Friedrich KUHL R 410A User Manual

Room Air Conditioners  
AUTO  
°F °C  
AUTO  
CONTINUOUS  
AUTO  
SYSTEM  
FAN MODE  
SCHEDULE  
FAN SPEED  
Standard Chassis R-410A Models  
Cool Only  
115-Volt: SS08M10, SS10M10, SS12M10, SS14M10  
208-230-Volt:  
SS12M30, SS15M30, SM18M30, SM21M30  
SM24M30, SL28M30, SL36M30  
Cool with Electric Heat  
208-230-Volt: ES12M33, ES15M33, EM18M34, EM24M35, EL36M35  
Heat Pump with Electric Heat  
208-230-Volt: YS12M33, YM18M34, YL24M35  
Heat Pump  
115-Volt: YS10M10  
Kuhl-ServMan (5-10)  
IMPORTANT SAFETY INFORMATION  
The information contained in this manual is intended for use by a qualied service technician who is familiar  
with the safety procedures required for installation and repair, and who is equipped with the proper tools  
and test instruments required to service this product.  
Installation or repairs made by unqualied persons can result in subjecting the unqualied person making  
such repairs as well as the persons being served by the equipment to hazards resulting in injury or  
electrical shock which can be serious or even fatal.  
Safety warnings have been placed throughout this manual to alert you to potential hazards that may be  
encountered. If you install or perform service on equipment, it is your responsibility to read and obey these  
warnings to guard against any bodily injury or property damage which may result to you or others.  
PERSONAL INJURY OR DEATH HAZARDS  
ELECTRICAL HAZARDS:  
Unplug and/or disconnect all electrical power to the unit before performing inspections,  
maintenance, or service.  
Make sure to follow proper lockout/tag out procedures.  
Always work in the company of a qualied assistant if possible.  
Capacitors, even when disconnected from the electrical power source, retain an electrical charge  
potential capable of causing electric shock or electrocution.  
Handle, discharge, and test capacitors according to safe, established, standards, and approved  
procedures.  
Extreme care, proper judgment, and safety procedures must be exercised if it becomes necessary  
to test or troubleshoot equipment with the power on to the unit.  
2
Do not spray or pour water on the return air grille, discharge air grille, evaporator coil, control panel,  
and sleeve on the room side of the air conditioning unit while cleaning.  
Electrical component malfunction caused by water could result in electric shock or other electrically  
unsafe conditions when the power is restored and the unit is turned on, even after the exterior is dry.  
Never operate the A/C unit with wet hands.  
Use air conditioner on a single dedicated circuit within the specied amperage rating.  
Use on a properly grounded outlet only.  
Do not remove ground prong of plug.  
Do not cut or modify the power supply cord.  
Do not use extension cords with the unit.  
Follow all safety precautions and use proper and adequate protective safety aids such as: gloves,  
goggles, clothing, adequately insulated tools, and testing equipment etc.  
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
REFRIGERATION SYSTEM REPAIR HAZARDS:  
Use approved standard refrigerant recovering procedures and equipment to relieve pressure before  
opening system for repair.  
Do not allow liquid refrigerant to contact skin. Direct contact with liquid refrigerant can result in minor  
to moderate injury.  
Be extremely careful when using an oxy-acetylene torch. Direct contact with the torch’s ame or hot  
surfaces can cause serious burns.  
Make sure to protect personal and surrounding property with re proof materials.  
Have a re extinguisher at hand while using a torch.  
Provide adequate ventilation to vent off toxic fumes, and work with a qualied assistant whenever  
possible.  
Always use a pressure regulator when using dry nitrogen to test the sealed refrigeration system for  
leaks, ushing etc.  
Make sure to follow all safety precautions and to use proper protective safety aids such as: gloves,  
safety glasses, clothing etc.  
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
MECHANICAL HAZARDS:  
Extreme care, proper judgment and all safety procedures must be followed when testing,  
troubleshooting, handling, or working around unit with moving and/or rotating parts.  
Be careful when, handling and working around exposed edges and corners of the sleeve, chassis,  
and other unit components especially the sharp ns of the indoor and outdoor coils.  
Use proper and adequate protective aids such as: gloves, clothing, safety glasses etc.  
Failure to follow proper safety procedures and/or these warnings can result in serious injury or death.  
3
PROPERTY DAMAGE HAZARDS  
FIRE DAMAGE HAZARDS:  
Read the Installation/Operation Manual for the air conditioning unit prior to operating.  
Use air conditioner on a single dedicated circuit within the specied amperage rating.  
Connect to a properly grounded outlet only.  
Do not remove ground prong of plug.  
Do not cut or modify the power supply cord.  
Do not use extension cords with the unit.  
Be extremely careful when using acetylene torch and protect surrounding property.  
Failure to follow these instructions can result in re and minor to serious property damage.  
WATER DAMAGE HAZARDS:  
Improper installation, maintenance or servicing of the air conditioner unit can result in water damage  
to personal items or property.  
Insure that the unit has a sufcient pitch to the outside to allow water to drain from the unit.  
Do not drill holes in the bottom of the drain pan or the underside of the unit.  
Failure to follow these instructions can result in damage to the unit and/or minor to serious property  
damage.  
4
INTRODUCTION  
This service manual is designed to be used in conjunction with the installation and operation manuals provided with  
each air conditioning system.  
This service manual was written to assist the professional RAC (Room Air Conditioner) service technician to quickly  
and accurately diagnose and repair malfunctions.  
This manual will deal with subjects in a general nature.  
Accumulator  
Outdoor Grille  
Discharge Air  
Compressor  
Fresh Air Vent  
Reversing Valve  
Evaporator Coil  
Condenser Coil  
Sleeve  
Air Intake Vents  
Electronic Control  
Board  
Control Key Pad  
Support Bar  
Blower Wheel  
Fan Blade  
Fan/Blower Motor  
Base Pan  
Air Intake From  
Sides and Bottom  
Control Key Pad  
(User Interface)  
Chassis Pull  
Out Handle  
IMPORTANT: It will be necessary for you to accurately identify the unit you are servicing, so you can be certain of a  
proper diagnosis and repair (See Unit Identication code on page 6).  
MODEL AND SERIAL NUMBER LOCATION  
Register the air conditioner  
Model information can be found on the  
name plate behind the front cover.  
For your future convenience, record  
the model information here.  
MODEL NUMBER  
MODEL NUMBER VOLTS 115  
AIR CONDITIONING CO. YS10M10A 60 HZ PH  
SAN ANTONIO, TEXAS SERIAL NUMBER VOLTS MIN 108 EER 12.0  
ASSEMBLED IN MEXICO LICY00008 AMPS 8.0  
COOLING  
HEATING  
REFRIGERANT XXXXXXXXX XXXXXXXXXX FUSE PROTECTED  
U
/
1
BTH/HR 6500 BTH/HR 6500 30.1 OZ R410A 600 PSIG HS XXXXXXXXX  
CIRCUITS USE 15A  
300 PSIG LS XXXXXXXXXX TIME DELAY FUSE  
XXXXXXXXXX  
X
L
XX  
XXXXX  
XXXXXXXXXX  
EER 10.4  
AMPS 7.0  
SERIAL NUMBER  
PURCHASE DATE  
MODEL NUMBER  
AIR CONDITIONING CO. YS10M10A  
SAN ANTONIO, TEXAS SERIAL NUMBER  
ASSEMBLED IN MEXICO LICY00008  
5
UNIT IDENTIFICATION  
Model Number Code  
S S 08 M 1 0 A  
8th Digit – Engineering  
Major change  
1st Digit – Function  
S = Straight Cool, Value Series  
Y = Heat Pump  
E = Electric Heat  
7th Digit – Options  
0 = Straight Cool &  
Heat Pump Models  
3 = 3 KW Heat Strip, Nominal  
4 = 4 KW Heat Strip, Nominal  
5 = 5 KW Heat Strip, Nominal  
2nd Digit  
S = Small Chassis  
M = Medium Chassis  
L = Large Chassis  
6th Digit – Voltage  
1 = 115 Volts  
3 = 230-208 Volts  
3rd and 4th Digit - Approximate  
BTU/HR in 1000s (Cooling)  
Heating BTU/Hr capacity listed in the  
Specication/Performance Data Section  
5th Digit  
Alphabetical Modier  
RAC Serial Number Identication Guide  
Serial Number  
Decade Manufactured  
A
K
A
R
00001  
L=0  
A=1  
B=2  
C=3  
D=4  
E=5  
F=6  
G=7  
H=8  
J=9  
Production Run Number  
Year Manufactured  
Product Line  
R = RAC  
A=1  
B=2  
C=3  
D=4  
E=5  
F=6  
G=7  
H=8  
J=9  
K=0  
Month Manufactured  
A=Jan D=Apr G=Jul K=Oct  
B=Feb E=May H=Aug L=Nov  
C=Mar F=Jun J=Sept M=Dec  
6
PERFORMANCE DATA  
EVAP. AIR TEMP. DEG.  
OPERATING  
PRESSURES  
R-410A  
REF.  
BREAKER  
FUSE  
60 Hertz  
Amps  
COOLING  
PERFORMANCE  
DATA*  
ELECTRICAL RATINGS  
F
CONDENSER Discharge Suction  
Sub-  
Cooling  
Super Heat  
Voltage  
Temp. TEMP DEG. F  
Drop F.  
Temp  
Temp  
Amps  
Cool  
Amps Locked Rotor Charge in  
Discharge Air  
Suction Discharge  
Heat  
Amps  
OZ.  
SS08M10-A  
SS10M10-A  
53  
52  
27  
28  
115  
119  
157  
150  
62  
65  
12  
15  
31  
28  
151  
145  
400  
455  
6.1  
8.0  
32.0  
50.0  
24.0  
51.0  
115  
115  
15  
15  
SS12M10-A  
SS14M10-A  
YS10M10-A  
50  
49  
56  
30  
31  
24  
118  
121  
114  
163  
170  
150  
60  
56  
64  
12  
10  
12  
23  
22  
14  
137  
132  
152  
435  
425  
395  
10.0  
12.0  
7.8  
57.0  
63.0  
34.5  
35.0  
29.0  
33.0  
115  
115  
115  
15  
15  
15  
7.6  
SS12M30-A  
ES12M33-A  
YS12M33-A  
SS15M30-A  
ES15M33-A  
SM18M30-A  
EM18M34-A  
YM18M34-A  
SM21M30-A  
SM24M30-A  
EM24M34-A  
YL24M34-A  
SL28M30-A  
SL36M30-A  
49  
51  
49  
53  
53  
54  
54  
50  
48  
46  
46  
56  
47  
51  
31  
29  
31  
27  
27  
26  
26  
30  
32  
34  
34  
24  
33  
29  
116  
115  
116  
121  
121  
122  
122  
118  
124  
129  
129  
121  
126  
129  
158  
158  
167  
171  
171  
160  
160  
168  
170  
179  
179  
176  
181  
188  
62  
62  
65  
62  
62  
62  
62  
60  
55  
55  
55  
62  
58  
56  
13  
13  
16  
14  
14  
9
21  
18  
21  
28  
28  
31  
31  
24  
28  
34  
34  
25  
26  
31  
142  
140  
140  
138  
138  
145  
145  
130  
137  
123  
123  
135  
133  
122  
405  
400  
455  
430  
430  
450  
450  
410  
455  
495  
495  
480  
430  
470  
4.8  
4.8  
5.2  
6.4  
6.4  
7.4  
7.4  
8.5  
9.4  
11.0  
11.0  
11.1  
13.5  
19.0  
30.0  
30.0  
26.0  
32.0  
32.0  
42.0  
42.0  
44.0  
46.0  
47.0  
47.0  
47.0  
60.0  
96.0  
33.0  
33.0  
34.5  
32.5  
32.5  
55.0  
55.0  
49.5  
55.0  
40.0  
40.0  
74.0  
78.5  
77.0  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208v  
230/208V  
230/208v  
230/208v  
15  
15  
15  
15  
15  
15  
30  
15  
15  
20  
30  
30  
20  
30  
16.0  
5.1  
16.0  
9
19.5  
8.5  
15  
10  
12  
12  
18  
12  
12  
12.2  
*Rating Conditions: 80 degrees F, room air temp. & 50% relative humidity, with 95 degree F, outside air temp & 40% relative humidity, all  
systems use R-410A.  
 ENERGY STAR® qualied  
SPECIFICATIONS  
Energy Estimated  
Room Side  
Air  
Efciency  
Ratio  
Yearly  
Moisture  
Net  
Weight  
Sleeve Lbs  
Cooling  
Heating  
Volts  
Cooling  
Amps  
Cooling  
Watts  
Heating  
Amps  
Heating  
Watts  
Operating Removal Circulation  
Model  
Capacity Btu Capacity Btu Rated  
COP  
EER  
Cost  
Pints/HR  
CFM  
Kühl  
SS08M10  
SS10M10  
SS12M10  
SS14M10  
SS12M30  
7900  
9500  
115  
115  
115  
115  
6.1  
7.7  
677  
848  
11.7  
11.2  
$54  
$68  
1.0  
2.0  
3.0  
3.5  
2.8  
3.5  
4.6  
6.0  
10.0  
8.5  
12.0  
265  
260  
300  
325  
275  
360  
350  
425  
390  
600  
725  
S
S
S
S
S
S
M
M
M
L
99  



106  
112  
116  
112  
116  
140  
132  
152  
193  
212  
12000  
10.0  
12.0  
1071  
11.2  
$86  
14000  
1444  
9.7  
$115  
$82  
11700/11200  
230/208 4.8/4.9  
1026/982  
11.4/11.4  
10.3/10.3  
10.7/10.7  
10.0/10.0  
9.4/9.4  
9.7/9.6  
8.5/8.5  

SS15M30 14500/14300  
SM18M30 17500/17200  
SM21M30 20800/20700  
SM24M30 23500/23300  
230/208 6.4/6.8 1405/1385  
230/208 7.4/8.0 1635/1617  
230/208 9.4/10.3 2080/2070  
230/208 11.2/11.9 2500/2479  
230/208 13.5/14.4 2865/2812  
230/208 19.0/20.5 4235/4200  
$112  
$131  
$166  
$200  
$229  
$338  




SL28M30  
SL36M30  
27800/27000  
36000/35700  
L
Kühl + Heat Pump  




YS10M10*  
9500  
7500  
115  
7.8  
812  
7.6  
743  
3.0  
11.7  
$65  
$89  
$147  
1.9  
3.0  
5.4  
7.0  
285  
265  
370  
600  
S
S
M
L
109  
115  
141  
197  
YS12M33 12100/12100 9400/9000 230/208 5.2/5.4 1120/1120  
YM18M34 18200/17800 15500/15400 230/208 8.5/8.9 1838/1798  
5.6/5.8  
1132/1139 2.4 10.8/10.8  
8.5/8.7 1833/1761 2.6  
9.9/9.9  
9.7/9.7  
YL24M35  
24000/23600 23500/23200 230/208 11.1/12.0 2474/2433 12.2/14.3 2610/2575 2.6  
Kühl + Electric Heat  
ES12M33  
11700/11200 10700/8900 230/208 4.8/4.9  
1026/982 16.0/14.7 3500/2900 3.3 11.4/11.4  
$82  
2.8  
3.5  
275  
360  
350  
390  
725  
S
S
M
M
L
113  
117  
141  
153  
213  
ES15M33 14500/14300 10700/8900 230/208 6.4/6.8 1405/1385 16.0/14.7 3500/2900 3.0 10.3/10.3  
EM18M34 17500/17200 13000/10600 230/208 7.4/8.0 1635/1617 19.5/17.0 4200/3500 3.1 10.7/10.7  
$112  
$131  
$200  
$338  
4.6  
EM24M34 23500/23300 13000/10600 230/208 11.2/11.9 2500/2479 19.5/17.0 4200/3500 3.1  
EL36M35 36000/35700 17300/14300 230/208 19.0/20.5 4235/4200 24.0/22.4 5500/4650 2.5  
9.4/9.4  
8.5/8.5  
10.0  
12.0  
R-410A  
* Operates on 115 volt and is not equipped with supplemental heat. Will not provide heat at temperatures below 40°F.  
Friedrich room air conditioners are designed to operate in outdoor temperatures from 60° F to 115°F.  
Due to continuing research in new energy-saving technology, specications are subject to change without notice.  
As an ENERGY STAR® partner, Friedrich Air Conditioning Co. has determined that the selected ENERGY STAR® () models meet the ENERGY  
STAR® guidelines for energy efciency.  
All models use  
environmentally  
friendly R-410A  
refrigerant.  
The consumer- through the AHAM Room Air Conditioner Certication Program- can be certain that the AHAM Certication Seal accurately states  
the unit’s cooling and heating capacity rating, the amperes and the energy efciency ratio.  
Estimated yearly operating cost based on a 2007 national average electricity cost of 10.65 cents per kWh.  
† The estimated yearly operating cost of this model was not available at the time the range was published.  
7
Installation Information / Sleeve Dimensions  
Thru-the-wall Installation  
Finished Hole  
Depth Shell Depth to  
Window Width  
Minimum  
Extension  
Into Room*  
Minimum  
Extension  
Outside*  
16 15/16”  
16 15/16”  
18 15/16”  
with Front  
Louvers  
Sleeve  
Height  
15 15/16"  
17 15/16"  
20 3/16"  
Width  
25 15/16"  
25 15/16"  
28"  
Minimum** Maximum Height  
Width  
26 3/16”  
26 3/16”  
28 ¼"  
Max. Depth  
7 3/8"  
S
M
L
29"  
29"  
27 3/8"  
27 3/8"  
29 7/8”  
42"  
42"  
42"  
16 3/16”  
18 3/16”  
20 3/8"  
8
8
¾"  
¾"  
5
5
¾”  
7 3/8”  
¾”  
35 ½”  
5 3/8”  
15 1/8”  
16 ½"  
* Minimum extensions when mounted in a window.  
** Minimum widths achieved using one side curtain assembly as opposed to both in a standard installation.  
NOTE: S,M and L sleeves may be installed in window with no side kits if properly installed.  
Circuit Rating/ Breaker  
Circuit Rating  
Breaker or  
T-D Fuse  
Wall Outlet  
Plug Face Power Cord  
(NEMA#) Length (ft.)  
Model  
Appearance  
SS08M10, SS10M10, SS12M10 and  
SS14M10. YS10M10.  
125V - 15A  
250V - 15A  
5 - 15P  
6 - 15P  
6
4
Front  
SS12M30, SS15M30, SM18M30 and  
SM21M30.  
SIDE VIEW  
(
SM24M30, SL28M30. ES12M33,  
ES15M33. YS12M33  
250V - 20A  
250V - 30A  
6 - 20P  
6 - 30P  
4
4
SL36M30. EM18M34, EM24M34,  
EL36M35. YM18M34 and YL24M35  
For the best cooling performance and highest energy efficiency  
Keep the filter clean  
Insulation  
Make sure that your air conditioner is always in top performing condition  
by cleaning the filter regularly.  
Good insulation will be a big help in maintaining desirable comfort levels.  
Doors should have weather stripping. Be sure to caulk around doors and  
windows.  
Provide good air flow  
Make sure the airflow to and from the unit is clear. Your air conditioner puts the  
conditioned air out at the top of the unit, and takes in unconditioned air at the  
bottom. Airflow is critical to good operation. It is just as important on the outside  
of the building that the airflow around the unit exterior is not blocked.  
Proper installation of seal gasket  
Make sure the seal gasket has been installed properly to minimize noise  
and improve efciency. If the seal gasket has not been installed, please  
refer to the installation instructions.  
Unit placement  
If your air conditioner can be placed in a window or wall that is shaded by a tree  
or another building, the unit will operate even more efficiently. Using drapes or  
blinds on the sunny side of the dwelling will also add to your unit’s efficiency.  
8
ELECTRICAL DATA  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
All electrical connections and wiring MUST be  
installed by a qualied electrician and conform to  
the National Electrical Code and all local codes  
which have jurisdiction.  
Failure to do so can result in personal injury or  
death.  
NOTICE  
FIRE HAZARD  
Not following the above WARNING could result in re or  
electically unsafe conditions which could cause moderate  
or serious property damage.  
Read, understand and follow the above warning.  
Wire Size  
Use ONLY wiring size recommended for single outlet branch circuit.  
Fuse/Circuit Breaker  
Use ONLY the correct HACR type and size fuse/circuit breaker. Read electrical ratings on unit’s  
rating plate. Proper circuit protection is the responsibiity of the homeowner.  
Grounding  
Receptacle  
Unit MUST be grounded from branch circuit through service cord to unit, or through separate  
ground wire provided on permanently connected units. Be sure that branch circuit or general  
purpose outlet is grounded.  
The eld supplied outlet must match plug on service cord and be within reach of service cord.  
Do NOT alter the service cord or plug. Do NOT use an extension cord. Refer to the table above  
for proper receptacle and fuse type.  
The consumer - through the AHAM Room Air Conditioner Certication Program - can  
be certain that the AHAM Certication Seal accurately states the unit’s cooling and  
heating capacity rating, the amperes and the energy efciency ratio.  
*HACR: Heating Air Conditioning and Refrigeration  
9
WARNING: Before Operating Your Unit  
WARNING  
NOTICE  
Do not use the LCDI device as an ON/OFF switch.  
Electrical Shock Hazard  
Make sure your electrical receptacle has the  
same configuration as your air conditioner’s  
plug. If different, consult a Licensed Electrician.  
Failure to adhere to this precaution may cause  
premature equipment malfunction.  
Do not use plug adapters.  
Do not use an extension cord.  
Do not remove ground prong.  
Once plugged in, the unit will operate normally without the need to reset  
the LCDI device. If the LCDI device fails to trip when tested or if the power  
supply cord is damaged, it must be replaced with a new power supply cord  
from the manufacturer. Contact our Technical Assistance Line at (800)  
541-6645. To expedite service, please have your model number available.  
Always plug into a grounded 3 prong oulet.  
Failure to follow these instructions can result in  
death, fire, or electrical shock.  
Make sure the wiring is adequate for your unit.  
Table 1.  
If you have fuses, they should be of the time delay type. Before you install  
or relocate this unit, be sure that the amperage rating of the circuit breaker  
or time delay fuse does not exceed the amp rating listed in Table 1.  
CIRCUIT RATING  
OR TIME DELAY  
FUSE  
REQUIRED  
WALL  
RECEPTACLE  
MODEL  
NEMA  
NO.  
AMP  
VOLT  
DO NOT use an extension cord.  
The cord provided will carry the proper amount of electrical power to the  
unit; an extension cord may not.  
SS08M10, SS10M10,  
SS12M10, SS14M10,  
YS10M10  
15  
125  
5-15R  
6-15R  
6-20R  
Make sure that the receptacle is compatible with  
the air conditioner cord plug provided.  
SS12M30, SS15M30,  
SM18M30, SM21M30  
15  
20  
250  
250  
SL25M30, SL28M30,  
ES12M33, ES15M33,  
YS12M33  
Proper grounding must be maintained at all times. Two prong receptacles  
The grounded receptacle should meet all national and local codes and  
ordinances. You must use the three prong plug furnished with the air  
conditioner. Under no circumstances should you remove the ground  
prong from the plug.  
SL36M30, EM18M34,  
EL25M35, EL36M35,  
YM18M34, YL24M35  
30  
250  
6-30R  
Test the power cord  
Figure 1  
All Friedrich room air conditioners are shipped from the factory with a  
Leakage Current Detection Interrupter (LCDI) equipped power cord. The  
LCDI device on the end of the cord meets the UL and NEC requirements  
for cord connected air conditioners.  
TEST  
RESET  
TEST  
RESET  
To test your power supply cord:  
WARNING  
TEST BEFORE EACH USE  
1. PRESS RESET BUTTON  
1. Plug power supply cord into a grounded 3 prong outlet.  
2. PLUG LCDI INTO POWER  
RECEPTACLE  
3. PRESS TEST BUTTON,  
RESET BUTTON SHOULD  
POP UP  
WARNING  
TEST BEFORE EACH USE  
1. PRESS RESET BUTTON  
2. PLUG LCDI INTO POWER  
RECEPTACLE  
3. PRESS TEST BUTTON,  
RESET BUTTON SHOULD  
POP UP  
2. Press RESET (See Figure 1).  
4. PRESS TEST BUTTON,  
FOR USE  
DO NOT USE IF ABOVE TEST  
FAILS  
3. Press TEST, listen for click; the RESET button trips and pops out.  
4. PRESS TEST BUTTON,  
FOR USE  
DO NOT USE IF ABOVE TEST  
FAILS  
WHEN GREEN LIGHT IS ON  
IT IS WORKING PROPERLY  
4. Press and release RESET (Listen for click; RESET button latches  
WHEN GREEN LIGHT IS ON  
IT IS WORKING PROPERLY  
and remains in). The power cord is ready for use.  
15/20A LCDI Device  
30A LCDI Device  
FRR001  
10  
FAN SPEED Button – Used to sequentially select between fan speeds.  
Depending on your model, you can select between LOW, MED, HIGH,  
and MAX and AUTO. Max setting not available on SL and Kuhl+ models.  
Control Panel Operation  
Let’s check out how to control your air conditioner. On the control panel,  
just to the left of the POWER , is a liquid crystal display (LCD). All of the  
control panel function buttons and mode icons can be viewed in Figure 1.  
When the  
in the display window, plus a fan speed icon (triangle) changes to indicate  
the new speed level. W fan speed automatically varies  
button is pressed, the fan speed is temporarily displayed  
hen auto is selected,  
Power On – Press the  
button to turn on the air conditioner. The  
depending on the set temperature on the control panel and the actual  
room temperature. Let me explain. Say for example you’re working in  
your garage and you need to open the big door for several minutes. The  
air conditioner will sense a wide difference between the set temperature  
and the actual room temperature when this occurs the system fan speed  
increases to MAX. The fan speed decreases (in step) as the temperature  
difference decreases. When the set point temperature is reached the FAN  
speed returns to the original setting.  
power button will illuminate to indicate the power is on. The backlight on  
the power switch will automatically dim to 20% intensity after 120 seconds  
of inactivity. The remote control can also be used to turn power ON / OFF  
(See Remote Control).  
Display –  
light. The back light has an automatic two (2) step dim function. After 120  
seconds of inactivity, the display dims to 20% intensity. After an additional  
120 seconds, the display switches off. Touching buttons will automatically  
bring the display to full brightness.  
SCHEDULE Button – The  
and off. The current day of the week is indicated as a dot underneath  
the day symbol. Pressing the button a second time turns the  
button turns the schedule function on  
There are four control push buttons on each side of the display.  
schedule function off. The schedule function comes preprogrammed with  
recommended energy savings values (Addendum 1). The values may  
be changed through the schedule program function (See Programmable  
Thermostat).  
SYSTEM Button – Allows the user to sequentially select,  
, HEAT , and FAN ONLY operation. Press the  
the display advances to the next mode. A new icon appears. At the same  
time, the mode displays for two (2) seconds, then returns the display to  
the temperature set point for modes other than FAN. Note that on cool  
Cool  
button and  
UP and DOWN arrows – Pressing either  
(UP) or  
(DOWN) button  
only units, there are no HEAT and  
modes.  
changes the desired room temperature. The factory preset lower and  
upper limits are 63° F (16° C) and 99° F (37° C). These buttons are also  
used to navigate between function options when using the User Menu or  
Maintenance Mode.  
FAN MODE Button – Selects between automatic  
operation. In the mode, the fan only turns on and off when the  
compressor operates or the heat function is enabled.  
or  
BACK Button – This button is used after a menu item has been selected.  
It takes the user back to the previous menu level and to save and exit.  
In the SYSTEM FAN ONLY Mode,  
is not available. In the  
mode, fans speed is determined by your selection on the  
button.  
DISPLAY/ENTER Button This button is used in conjunction with User  
Menu and Maintenance Mode operation to select items. This button may  
also be used to alternatively display the ROOM TEMPERATURE,  
OUTDOOR TEMPERATURE, and TIME. If the display is left inactive for  
10 seconds it will reset to the TEMPERATURE SET POINT.  
Figure 1  
FRONT  
PANE L  
LOCK  
FAN  
ONLY  
MODE MODE  
MAINTENANCE  
REQUIRED  
AUTO  
MODE  
COOL  
MODE  
HEAT  
FILTER  
MAINTENANCE WAIT  
BACK  
CHECK  
FI LTER OFF RESET  
ON EXIT  
SYSTEM  
AUTO  
OUTDOOR TEMP  
ROOM TEMP 
FAN  
MODE  
AUTO  
HE AT -> SET POINT <- COOL  
CONTINUOUS  
F
A
M
AUTO  
FAN  
P
M
SPEED  
C
M T  
W
T
F
S
S
POWER  
WAKE  
AWAY  
R E TURN NIGHT  
DISPLAY  
ENTER  
SCHEDULE  
BUTTONS SCHEDULE  
ON/OFF  
SCHEDULE  
PERIODS  
BUTTONS  
11  
ALERTS (The control system has five (5) customer alerts)  
CHECK FILTER  
appears on screen. The word “  
” appears next to the  
button.  
The alert is issued when the fan run time is greater than 500 hours.  
This alert may be reset by the user (Refer to Special Functions, Filter Reset).  
Maintenance Required – When maintenance is required, a service icon  
appears on screen. This icon will not be dismissed until maintenance  
has been performed. If the service icon  
The hour digits flash first. The user presses the  
to change the hours. To change AM-PM, the hours must be  
advanced 12 hours. Press the key to change to the  
minutes. To exit the selection process, user presses the  
key which will go to the time screen.  
or  
the icon  
is on standby the system has sensed an abnormal condition.  
goes away.  
is established the service icon  
Wait – The WAIT icon illuminates when the compressor lockout is active.  
Whenever the compressor shuts off, system pressures must be allowed  
to equalize. At this time, an internal timer begins a count-down from up to  
240 seconds. If a demand for heat or cool occurs during this count-down  
The minutes digits flash. The user presses the  
or  
to change the minutes. Press the key to change the days.  
the WAIT icon  
displays letting you know that the compressor will not  
To exit the selection process, the user presses the  
which will go to the time screen.  
key  
operate until the count-down has completed. This timer prevents damage  
to the unit if it tries to start too quickly after it stops running. Normally the  
WAIT icon  
is off. Once the timer has cleared, the air conditioner will  
heat or cool based on the temperature setting. Electric heat is not affected  
by this timer.  
The dot underneath the days of the week begins to blink to  
indicate which day it is. If the user has not set the date before,  
the dot starts on Monday. If the user is making a correction to  
previously set information the dot appears under whichever  
Protection Alert (Freeze) – If the room freeze protection is active, the  
display indicates this by showing Room Freeze Protection "FRZ". Once  
day the unit thinks it is. The user can press  
the dot left or right (respectively) along the week. The user  
presses to loop back to the hours setting. To exit the  
or  
to move  
temperature is less than 40° F (4° C), and the air conditioner is equipped with  
electric heat, the room freeze protection will activate. The air conditioner  
will run high fan and electric heat until the room temperature reaches  
selection process, the user presses the  
to the time screen.  
key which will go  
46° F (8° C). Pressing the  
button delays the freeze protection function  
Low Battery – When the battery is low a warning display  
will be  
Tuesday has been selected. The user presses  
back to the hours setting. To exit the selection process and  
to loop  
inserted before other messages such as “COOL”. If the Low Battery  
alert is on, the battery in the control unit must be changed. Refer  
to the changing the battery procedure. Once the battery is changed, the  
alert message will go off. Refer to Troubleshooting Tips. Under normal  
conditions the battery life should be greater than 7 years.  
BACK  
accept the changes, the user presses the  
to the time screen.  
key which will go  
Special Functions  
Time Setting – When in the User Menu, on the Control Panel, use the  
Panel Lock  
– The front panel push buttons can be locked to prevent  
(UP) and  
(DOWN) to select TIME. Push  
, the hours segment  
SCHEDULE  
inadvertent operation. To lock the front panel, press and hold the  
+
(UP) and (DOWN) to set the hour, then push  
buttons for three (3) seconds. A double beep indicates your mode  
change was successful and a  
the display, press and hold the  
(UP) and  
(DOWN)  
icon appears on the display. To unlock  
buttons for three (3) seconds.  
to set the minutes, then push  
.
SCHEDULE  
+
NOTE: If the AM or PM indicator is incorrect, push  
until the hours  
(DOWN) to advance  
. The day of the week  
The  
icon will no longer be visible.  
(UP) or  
Filter Reset –  
and holding the  
icon displays, the timer may be reset by pressing  
button for three (3) seconds. A beep indicates the  
the hour segment 12 hours, then push  
displays. Use the  
day. Press the  
(UP) or  
(DOWN) to select the current  
system timer was reset and the  
no longer be visible.  
icon and the word " RESE T " will  
key to save and go back to the TIME screen.  
Press  
(UP) to go to the next menu 1224.  
User Menu Functions – The User Menu Functions allows you to change  
the following selections: Set TIME, 12/24 Hour Clock Format, BEEP ON /  
OFF, DIM ON / OFF, Emergency Heat (EMHT) ON / OFF, Auto BAND Adjust,  
F/ C Select, FRZ ON / OFF, Temp Offset (TO) and the Automatic Temperature  
Sensing Feature (ATSF).  
NOTE: Pressing the  
button again will exit the user menu function  
mode. Or simply leave the control inactive for 15 minutes and  
the control will return back to normal operation.  
To enter the User Menu, press and hold  
selection appears. Use the (UP) or  
through the User Menu. Press the  
for 3 seconds, the TIME  
(DOWN) buttons to scroll  
button to enter the displayed  
function. If left inactive for 15 minutes the User Menu display will no longer  
be visible and it returns to normal operation mode display. To manually  
exit the User Menu, press the  
button.  
12  
BACK  
EXIT  
BACK  
SYSTEM  
EXIT  
SYSTEM  
FAN  
MODE  
FAN  
MODE  
FAN  
SPEED  
FAN  
SPEED  
DISPLAY  
ENTER  
DISPLAY  
ENTER  
SCHEDULE  
SCHEDULE  
User presses  
and Emergency Heat Off. Press the  
change and exit the selection process.  
or  
to toggle between Emergency Heat On  
User presses  
24HR display. To exit the selection process and accept the  
change, press the key.  
or  
to toggle the format between 12HR and  
key to accept the  
Emergency Heat – The Kühl+ heat pump models (YS, YM, YL) have  
a special feature that is designed to keep the unit providing heat.  
Clock Type – You may select between a 12 hr and 24 hr clock. When  
1224 is displayed press the key then press (UP) or (DOWN)  
to toggle between 12 hr and 24 hr clock. To accept the change, press the  
key to return to the 1224 screen. Press the (UP) to go to the  
next menu BEEP.  
key then press  
(UP) or  
When EMHT is displayed press the  
(DOWN) to toggle between ON and OFF.  
To accept the change, press the  
key to return to the EMHT screen.  
Press the (UP) to go to the next menu BAND.  
In the unlikely event of a compressor failure, the heat pump unit may be  
switched to operate in the electric heat mode only until repairs can be  
made.  
BACK  
EXIT  
SYSTEM  
FAN  
MODE  
FAN  
SPEED  
BACK  
EXIT  
SYSTEM  
DISPLAY  
ENTER  
SCHEDULE  
FAN  
MODE  
FAN  
SPEED  
User presses  
Off. Press the  
selection process.  
or  
to toggle between Beep On and Beep  
key to accept the change and exit the  
DISPLAY  
ENTER  
SCHEDULE  
The menu allows the user to adjust the minimum spread  
between the Auto Cool set point and the Auto Heat set point.  
Press the  
or  
key to adjust. The adjust range is 3 to 10.  
Audible Alerts – You can select to have the control beep when entering  
When BEEP is displayed press the  
key then press  
(DOWN) to toggle between ON and OFF. To accept the change,  
key to return to the BEEP screen. Press the (UP) to go  
(UP)  
menus.  
or  
press the  
Auto Changeover ‘Dead Band’ – A buffer Zone between heating and  
cooling in which no conditioning occurs. For Kühl+ models with the auto  
changeover feature you can select the temperature band between heating  
and cooling. From the factory the band is set at 3° F (-16° C). The band is  
adjustable from 3° F (-16° C) to 10° F (-12° C). When BAND is displayed  
to the next menu EMHT on Kühl+ models or F C for Kühl models.  
press the  
3 and 10. To accept the change, press the  
screen. Press the  
key then press  
(UP) or  
(DOWN) to toggle between  
key to return to the BAND  
(UP) to go to the next menu F C.  
FAN  
SPEED  
DISPLAY  
SCHEDULE  
ENTER  
BACK  
EXIT  
SYSTEM  
FAN  
MODE  
User presses  
Press the  
or  
to select between AUTO, DM 20, OFF.  
key to accept the change and exit the  
FAN  
SPEED  
selection process.  
DISPLAY  
ENTER  
SCHEDULE  
The Dim Auto automatically dims the display to 20% and then  
turns it off after a period of time. The Dim 20 setting behavior  
is similar to AUTO, but prevents the display from turning off.  
Minimum brightness is 20%. The Dim Off setting forces the  
display to run at full brightness.  
User presses  
or  
at the same time to toggle between  
Fahrenheit or Celsius as their temperature unit of choice.  
Press the  
process.  
key to accept the change and exit the selection  
Fahrenheit / Celsius Selection – You may select between displaying  
temperature in F or C. When F C is displayed press the key then  
press  
change, press the  
(UP) or  
(DOWN) to toggle between F and C. To accept the  
key to return to the F C screen. Press the  
(UP) to go to the next menu FRZ.  
13  
BACK  
EXIT  
SYSTEM  
FAN  
MODE  
FAN  
SPEED  
DISPLAY  
ENTER  
SCHEDULE  
User presses  
Press the  
or  
to select between ATSF On or Off.  
key to accept the change and exit the  
selection process.  
User presses  
or  
to select between Freeze Protection On  
& Freeze Protection Off. Press the  
key to accept the  
change and exit the selection process.  
Freeze Protection – The Kühl+ models have a special feature that is  
designed to keep the interior space above freezing by energizing the  
electric heater anytime the indoor room temperature falls to 40° F (4° C).  
With the freeze protection feature turned on, when the unit senses the  
indoor temperature fall to 40° F (4° C) the unit will run the heater and high  
fan until the space reaches 46° F (8° C) When FRZ is displayed press  
the  
and OFF. To accept the change, press the  
screen. Press the  
key then press  
(UP) or  
(DOWN) to toggle between ON  
key to return to the FRZ  
Automatic Temperature Sampling Feature - The automatic temperature  
sampling feature maintains a balanced temperature throughout the room  
by circulating the air for 30 seconds once every 9 minutes that the unit is  
not running when it is set to cooling or heating mode. By circulating the air  
the unit can detect hot or cold areas in the room and operate the unit to  
cool or warm the room as necessary. This function is only available when  
the fan mode is set to ‘AUTO’ or in COOL or HEAT Mode. (Heating function  
only available on Kuhl+ units)  
(UP) to go to the next menu TO.  
BACK  
EXIT  
SYSTEM  
FAN  
MODE  
FAN  
SPEED  
DISPLAY  
ENTER  
SCHEDULE  
User presses  
or  
to increment/decrement the temperature  
offset (TO) for the room temperature sensor. (Maximum offset  
= +/- 8 degrees F). Press the  
and exit the selection process  
key to accept the change  
Y
For display only. No user selectable options.  
Temperature Offset – In some cases the built in thermostat on the unit  
may not display the temperature as it is felt in the room. This can be caused  
by many things including the size of the unit, the heat load on the room or  
other factors. Friedrich allows you to select the appropriate temperature  
offset to make the temperature readout as accurate as possible for your  
application. In many cases the factory 0° F (-18° C) offset will provide  
an accurate temperature readout. To change the offset follow these  
F
instructions. When TO is displayed press the  
(UP) or (DOWN) to toggle between 0° F (-18° C) and 8° F (-13° C).  
In most instances an offset from 0° F (-18° C) to 2° F (-17° C) is all that is  
necessary. To accept the change, press the key to return to the TO  
(UP) to go to the next menu ATSF.  
key then press  
Firmware Version - When VER is displayed press Display /  
Enter key. The firmware version is displayed as left digit  
(Major) and right digit (Minor). This version number should be  
used along with Model and Serial numbers for service.  
screen. Press the  
You may cycle through the menus using the  
to access any of the menus.  
(UP) or  
(DOWN) keys  
DIGITAL CONTROL PANEL'S ACCESS CODES SUMMARY  
Key Sequence  
Filter Reset  
Action  
Press BACK key for 3 sec+ play double beep ()  
Enter User Menu  
Enter Maintenance Menu  
Schedule ON/OFF  
PressDISPLAY/ENTER key for 3 sec+ play double beep ()  
Press SYSTEM + SCHEDULE + BACK + DISPLAY/ ENTER for 3 sec+ play double beep ()  
Press SCHEDULE once each time  
Enter & Exit Schedule Programming Press SCHEDULE for 3 sec+ play double beep ()  
Reset Error Codes & Error History  
Lock Control Panel  
Press  
+
for 3 sec+ play double beep ()  
Press SCHEDULE + DISPLAY/ENTER for 3 sec + play double beep ()  
14  
FAN SPEED Button – Used to sequentially select new fan speed, plus  
Remote Control Operation  
FA N  
SPEED  
AUTO operation. When the  
button is pressed, the fan speed is  
Remote Control – Refer to Figures 11 and 12 during operation description.  
temporarily displayed in the display window, plus a fan speed icon (triangle)  
changes to indicate the new speed level. Fan speed automatically varies  
depending on the set temperature on the control panel and the actual  
room temperature. Let me explain. Say for example you’re working in  
your garage and you need to open the big door for several minutes. Since  
there is a big difference between your set temperature and the actual room  
temperature the system fan speed increases to MAX. It remains at this  
speed until the room temperature matches the set temperature.  
Getting Started – Install two (2) AAA batteries in the battery compartment  
located on the back of the unit.  
Operation – The remote control should be within 25 feet of the air  
conditioner for operation (Refer to Figure 10 for effectiveness). Press the  
button to turn the remote on. The remote will automatically power off  
after 15 seconds if the buttons are not being pressed. The remote must  
be on to control the unit.  
SCHEDULE  
– The  
SCHEDULE Button  
off. Pressing the  
button turns the schedule function on and  
button a second time turns the schedule function  
SCHEDULE  
POWER Button – Turns remote and unit on and off.  
off. Only the schedule icon will be displayed.  
SYSTEM Button – Allows the user to sequentially select,  
Cool  
,
HEAT , and FAN ONLY operation. When the button is pressed, the  
display indicates which mode has been selected via a display message.  
Note that when the heating function is not available, the system will  
automatically skip the HEAT and AUTO modes.  
UP and DOWN Arrows – Pressing either the  
(UP) or  
(DOWN)  
button changes the desired room temperature. The factory preset lower  
and upper limits are 60° F (16° C) and 99° F (37° C). These buttons are  
also used to navigate between function options when using the User Menu  
or Maintenance Mode.  
FAN MODE Button – Selects between automatic (  
) or  
operation. In the AUTO mode, the fan only turns on and off when the  
compressor operates or the heat function is enabled.  
Remote Effectiveness  
Hand Held Remote – Has an operating range of up to 25 ft. The infrared  
remote control signal must have a clear path to transmit the command to  
the air conditioning unit. The remote signal has some ability to "bounce"  
off of walls and furniture similar to a television remote control. The diagram  
below shows the typical operating range of the control in a standard room  
with 8 ft high ceilings.  
NOTE: AUTO is not available in the FAN ONLY Mode, the display  
indicates  
. In the  
mode, fan speed is  
button.  
determined by your selection on the  
TOP VIEW  
25ft  
25ft  
7.5ft  
SIDE VIEW  
4ft  
60°  
60°  
6ft  
30°  
45°  
60°  
60°  
45°  
45°  
8ft  
25ft  
30°  
30°  
45°  
30°  
16ft  
8ft  
25ft  
25ft  
25ft  
25ft  
25ft  
Changing Temperature from F˚ (Fahrenheit) To C˚ (Celsius) or Reverse  
Be within 25' of unit with the remote control. Press the SYSTEM and FAN MODE buttons at the same time and hold for 3  
seconds. The display will show the temperature in Celcius. Do the same to reverse temperature to F˚ (Fahrenheit).  
15  
Remote Control Operation (Continued)  
DISPLAY  
SYSTEM  
FAN MODE  
POWER  
TEMPERATURE  
UP  
TEMPERATURE  
DOWN  
FAN SPEED  
SCHEDULE  
AUTO  
ICON  
COOL  
ICON  
HEAT  
ICON  
FAN ONLY  
ICON  
SYSTEM  
MODE  
°F / °C  
ICONs  
FAN  
MODE  
FAN  
SPEED  
SCHEDULE  
ICON  
2 X 16 SEGMENT  
DISPLAY  
16  
ELECTRONIC CONTROL SYSTEM MAINTENANCE  
Introduction  
This section contains information on the maintenance alerts, temperature limiting, diagnostic test and how to access. The electronic  
control system has a built in maintenance sub system which works constantly behind the scenes to help identify problems with the air  
conditioner or control system. When maintenance is required, a service icon appeasrs on the display screen.  
This icon  
will not be dismissed until maintenance has been performed or the problem cleared.  
Note: The wrench icon may be on steady or flash, depending on severity. Maintenance should only be performed by qualified service  
personell.  
Display  
Testing the Display  
Press the FAN MODE and FAN SPEED buttons at the same time for 3 seconds. All of the display's icons and functions  
should light up. If any of them do not light up, the display should be replaced. When the buttons are released, the display  
reverts to the original display.  
17  
Electronic Control System Maintenance Operation  
To Enter the Maintenance Section:  
Press SYSTEM+SCHEDULE+BACK+DISPLAY/ENTER for 6 seconds.  
There are 5 maintenance sub-menus M1 through M5.  
Access  
Maintenance Sub-Menus  
M1  
M2  
M3  
Service Only  
Service Only  
Service Only  
– Temperature High Limit  
– Temperature Low Limit  
– Test Mode Access  
M4 – Provision Switch Setting & State  
M5 – Alarms & History  
Factory Use Only  
Service Only  
M6  
Factory Use Only  
Factory Use Only  
Pressing the or key cycles through the sub-menus. Press DISPLAY/ENTER to  
enter a sub-menu. The BACK key is used to exit the menu. Extreme care must  
be taken when modifying parameters in the maintenance menus.  
18  
Temperature High Limit  
Maintenance function 1 is ready to be selected. Press DISPLAY/ENTER to access  
the function.  
User presses  
or  
to increment or decrement the upper temperature limit. 99°F  
is the maximum upper limit. The current stored high limit is displayed when the  
screen is selected. Press the BACK key to accept the value, and exit the sub-menu  
to the M1 screen.  
Temperature Low Limit  
Maintenance funtion 2 is ready to be selected. Press DISPLAY/ENTER to access  
the fuction  
User presses  
or  
to increment or decrement the lower temperature limit. 60°F is the  
minimum lower limit. The current stored lower limit must be displayed when the screen  
is selected. Press the BACK key to accept the value, and exit the sub-menu to the M2  
screen.  
M3 – Test Mode Access  
Maintenance function 3 is ready to be selected. Press  
DISPLAY/ENTER to access the function.  
User presses the or key to toggle the Test Mode  
ON/OFF. Press the BACK key to accept the change  
and exit the sub-menu to the M3 screen.  
This test selects the system mode of operation directly.  
The Following functions Can be Tested  
1. System Mode: Cool/Heat Pump Compressor, Electric Heat, Fan Only  
2. Fan operation and speeds  
Test mode Bypasses:  
1. Compressor lock out (time delay)  
2. All relay switch’s delays  
3. All thermistors delay  
4. Automatic heat/cool changeover delay  
5. System settings  
If M3 switch is left ON it will reset to OFF automatcally after 15 minutes of inactivity.  
19  
M4 – Switch Access (Unit Configuration)  
FACTORY USE ONLY  
Error Code  
On/Off  
M5 – Error Codes & History  
Number of Errors  
Error Code  
Maintenance funtion 5 is ready to be selected. Press DISPLAY/ENTER to access the function.  
The error code display shows the error code number on the left, and the error code  
history on the right. User presses the  
or  
keys to cycle through the error codes.  
The current state of the error code is shown with the On/Off icon. To exit the  
maintenance sub-menu, press the BACK key to return to the M5 screen.  
Shown on this display is error code 1 with 4 occurances. The current state is on.The  
error code display shows the error code number on the left, and the error code history  
on the right. User presses the  
or  
keys to cycle through the error codes. The  
current state of the error code is shown with the On/Off icon. To exit to the  
maintenance sub-menu, press the BACK key to return to the M5 screen. Shown on  
this display is error code 6 with 3 occurances. The current state is off.  
To Clear Error Codes’ History:  
Hold the  
or  
keys simultaneously for 3 seconds. See page 56 for alarm status and error codes.  
M6 – Factory Use Only  
20  
UNIT OPERATION  
There are two basic ways to operate the unit - Front Panel and Wallstat. The Front Panel and Wallstat are never active at the  
same time. Switching between these modes is controlled via the (FP) jumper on the Wallstat connector. When the jumper is  
ON, the mode = Front Panel.  
Front Panel  
System Mode Sequence (SCHEDULE = OFF)  
There are two system modes of operation. One for a cool only unit (see figure 1) and one for a heat-cool unit (see figure 2).  
System parameters for each system mode are saved when exiting a system mode, and retrieved when entering a new  
system mode.  
Figure 1  
System Mode: Cool Only Units  
Figure 2  
System Mode: Heat - Cool Units  
21  
COOL-HEAT SET POINTS  
The air conditioner control system is designed to control different product configurations  
with a select set of features. Some models just cool, some cool and heat with electric  
heat, and others cool and heat with a heat pump and/or electric heat.  
The system set points are mapped to the internal controls as shown below.  
Control  
1.5  
1.5  
Deadband  
System Set Point Mapping Figure  
There are 8 stored & variable set points in the system:  
1 - ASPC: Auto Set Point Cool  
2 - ASPH: Auto Set Point Heat  
3 - CSP: Cool Only Set Point  
4 - HSP: Heat Only Set Point  
5 - SASPC: Scheduler Auto Set Point Cool  
6 - SASPH: Scheduler Auto Set Point Heat  
7 - SSPC: Scheduler Set Point Cool Only  
8 - SSPH: Scheduler Set Point Heat Only  
22  
ELECTRONIC CONTROL SEQUENCE OF OPERATION  
Compressor and Reversing Valve Control  
Active Mode  
Compressor  
Reversing Valve State  
De-Energized  
Energized  
Cooling  
On  
On  
Off  
Off  
Heat - Heat Pump  
Heat - Electric  
Fan Only  
* The Reversing valve stays in the last state until a call for heat or cooling (see gure below)  
Compressor Operation:  
The reversing valve only changes when required  
to provide cooling or heat pump. The RV valve  
stays in it's last state until required to change.  
Cooling Mode  
Once the ambient temperature rises past the cool demand threshold (Cool Set Point + 1.5 ˚F) (see gure below), and  
the compressor is not locked out, the cooling cycle begins. As shown in the gure below, the fan is started 5 seconds  
prior to the compressor. Once the ambient temperature has been lowered to the cool set point (Cool Set Point minus  
.25 ˚F), the cooling cycle starts to terminate by shutting off the compressor. After a 30 seconds delay, the fan is shut  
off. (See gure below for graphic details)  
23  
Heating Mode Control Operation  
There are two heating methods: Heat Pump and Electric Resistance Heat.  
There are 3 types of units that provide heating: Heat Pump Only (Model YS10M10)  
Heat Pump with Electric Heat and Cool with Electric Heat.  
Heat Control Operation Heat Pump Only  
Once the ambient temperature falls below the Heating Demand Threshold  
(1.5 ˚F Below the Heat Set Point Temperature), the heating cycle begins. The fan is turned on 5 seconds later. Once  
the ambient temperature has been raised to the Heat Satised Point (Set point + .25 ˚F), the compressor is turned  
off. The fan is turned off 30 seconds later. The gure below illustrates the basic heat pump operation.  
Heat Control (Heat Pump Only)  
24  
Heat Pump With Electric Heat Operation  
This heating is more complex due to the possibility of two heating methods. If the ambient indoor temperature is be-  
low the heat demand threshold (1.5˚F below the heat set point temperature), and the compressor is not locked out,  
turn on compressor. If the ambient indoor temperature is 0.25˚F above the heat set point turn off the compressor.  
If the compressor is locked out & electric heat is available:  
1. Turn on the electric heat until the compressor is not locked out.  
2. After lockout, turn off the electric heat, wait 5 seconds, then turn on the compressor.  
If Electric Heat is Available  
After the Heat button is initially pressed, the unit will run the electric heater until the initial set point is satised (Hot Start  
Feature). After the initial start, the unit will switch to Heat Pump heat and decide between Heat Pump heat and Electric  
heat based on the following two monitored conditions:  
Condition 1  
If the outdoor coil temperature sensor drops to 30 ˚F or less for 2 consecutive minutes, the unit will switch to electric heat  
if available. Thereafter, the unit will switch back to Heat Pump heat if the outdoor coil temperature sensor rises to 45 ˚F or  
greater.  
If Electric Heat is not available (out of order) and the outdoor coil temperature sensor drops to 30 ˚F or less for 2  
consecutive minutes, then the compressor and fan will turn off. Thereafter, the unit will switch back to Heat Pump heat if  
the outdoor coil temperature rises to 45 ˚F or greater.  
25  
Heat Pump With Electric Heat Operation (Continued)  
Condition 2  
If the Δ (delta) (set point temperature minus the ambient indoor temperature) is greater than 5 ˚F, then the unit will switch  
to electric heat, if available. The unit will continue to operate with electric heat until the heat demand is satised. Note that  
the electric heat switches on after the Δ temp passes 5°F and the heat pump switches off. Also note that the electric heat  
will run until the heat demand is satised. When another heat demand cycle is initiated, the heat pump will run unless the  
Δ temp is greater than the electric heat threshold.  
Emergency Heat  
If a compressor fails in the heating season, the Emergency Heat allows the user to override the Heat Pump and heat with  
electric heat only. This is controlled via the user interface (See the User Menu Functions page 12).  
Note that if heat is the rst demand cycle (demand cycle = call for heat or call for cooling) after power restoration, the  
control system will run electric heat for the entire cycle if the unit is equipped with electric heat.  
Electric Heat Operation in Cool with Electric Heat Units  
When in the Heat mode, with and without Fan Mode Auto (Fan cycling):  
If the indoor ambient temperature is below the Heat Demand Threshold (Heat Set Point minus 1.5 ˚F), turn on electric  
heat. If Ambient is 0.3 ˚F above the Heat Set Point turn off the electric heat.  
System Mode Auto  
This mode provides automatic change over between cool and heat. The auto mode runs based on the room ambient  
temperature vs. the Demand Thresholds. It is only available in Heat-Cool Unit.  
Notes:  
The Heat Demand Threshold and the Cool Demand Threshold values are derived from the Auto Set Point in the Auto  
Mode (refer to page 22). There is a buffer zone as shown in gure , where no heating or cooling is allowed to occur. It is  
critical that the Cool Demand Threshold be greater than the Heat Demand Threshold by a minimum of 3° while in the Auto  
System Mode. For example, if a user enters a value for the Auto Cooling Set Point that violates the minimum Δ 3° rule, the  
Auto Heating Set Point will adjust accordingly. This buffer zone (BAND) can be manually adjusted from 3 to 10° (see the  
BAND section page 13).  
When programming the schedule, the user has the exibility to enter the schedule automatic set point cooling (SASPC)  
and the schedule automatic set point heating (SSPH) set points directly. These values are monitored to ensure that they  
do not violate the minimum 3° Δ rule. If a violation is detected, the opposite set point will adjust to compensate. The  
individual heating and cooling rules apply to the auto mode.  
Automatic Change Over Delay (Cool with Heat Units)  
The change over delay ensures that any system heating or cooling over shoot does not trigger an opposite demand cycle.  
The change over delay = 15 min. This timer blocks the opposite demand cycle from running until the timer expires. As an  
example, if the last demand was a cool cycle, and another cool cycle is requested, the timer will not block the request.  
However, if the last demand cycle was a cool cycle, and heat cycle is requested, the timer will block the request until the  
change over delay is expired.  
26  
Compressor Lock Out Time  
The lockout feature ensures that the compressor is de-energized for a period of time. The timer varies randomly  
from 180 to 240 seconds  
The compressor lockout is initiated every time the compressor is “off” due to:  
(1) Satisfying the temperature set point  
(2) Changing mode to fan only or heat  
(3) Turning the unit off  
(4) Control is rst plugged in or power is restored after failure  
(5) Line power is restored from a brown out condition  
Wait ICON (Hour Glass)  
The wait icon will be turned on when the compressor is locked out and during demand for cooling or heat pump  
compressor operation. The Wait ICON will be turned off when the condition clears.  
Cooling Fan Delay  
Fan cycle/Auto mode only  
When unit cycles cooling ON – starts the fan 5 seconds EARLY. When unit cycles cooling OFF – DELAYS the fan  
off for 30 seconds  
Note: this fan delay is disabled during Test Mode  
Heating Fan Delay  
This is only for fan Mode Auto (Fan cycles with cool/heat operation) and not for continuous fan mode. When unit  
cycles Heating ON – starts the fan 5 seconds EARLY. When unit cycles Heating OFF – DELAYS the fan off for 15  
seconds  
Note: the fan delay is disabled during Test Mode  
Fan Speed Change Delay  
Relay activation is delayed by a minimum number of seconds. The default for this value is 2 seconds and is used to  
eliminate relay chatter.  
Fan Only System Mode  
The fan is turned on and runs at the specied manually set speed.  
Only the Fan is turned on. Cool or Heat operation are off.  
(This is different than FAN MODE CONTINUOUS where the fan is on with the cool or heat operation).  
Fan Only Rules  
1. If the SYSTEM FAN ONLY MODE is selected, the Auto fan mode is disabled, and the fan mode is forced to  
continuous. In addition, the auto fan speed is disabled. If the user presses the fan speed key, the menu will skip over  
the auto selection. The set point temperature display is off.  
2. Any fan speed may be manually selected during Fan Only Mode.  
27  
Fan Operation (Front Panel Mode)  
Heat – Cool – Auto – Fan Only  
Models starting with SS, SM have 4 speeds. Models with SL, and all Kuhl+ have 3 speeds  
Speed Selection  
1
2
3
4
AUTO  
AUTO Operation, but never  
turns Off. Uses cool set point  
or heat set point vs. ambient  
temperature. When there is  
no demand, operate at the  
lowest available speed.  
Continuous  
"On" "  
Turns  
On"  
Turns  
"On" "  
Turns  
On"  
Turns  
Fan  
On or  
On or  
On or  
On or  
AUTO operation turns On or  
Off with heat or cool demand  
Uses cool set point or heat  
set point vs. ambient  
Off with  
heat or  
cool  
Off with  
heat or  
cool  
Off with  
heat or  
cool  
Off with  
heat or  
cool  
AUTO  
demand  
demand  
demand  
demand  
temperature  
Mode  
Fan Only  
"On" "  
On"  
"On" "  
On"  
Disabled  
Fan ICON Detail  
The system may have a 3 or 4 speed fan. The Fan Speed ICON will Display as per the table below.  
Note that in the AUTO mode, the speed of the fan will be shown by illuminating the number of bars in the speed triangle.  
Fan Mapping  
28  
UNIT OPERATION WITH A WALL-STAT  
Front Panel Display Operation in Wall-Stat Mode  
The indoor ambient temperature sensor is disabled. All buttons are disabled with the following exception:  
A. Maintenance commands.  
B. The user menu for Freeze protection (Display/Enter button for Kuhl+ only units).  
C. First Button push to illuminate the back light (display will dim).  
Maintenance features are operational. This includes the Check Filter, Lock Panel, M3, M4, M5, and the Service  
wrench icon. Under T-stat operation, as a default, the selected operating Mode (Cool, Heat or Fan) will not show on  
the front panel. The Service ICON ( ) is displayed if a malfunction is detected.  
Cool/Heat/Fan modes and Fan speed operations are controlled by the remote wall thermostat.  
The fan speeds can be Low or Max for 4 speed units and Low or High for 3 speed units. (T-stat selected must have  
2 speed capabilities)  
Thermostat terminals requirements:  
Must be single stage heat/cool.  
For cooling only units: C, R, G, Y.  
For cooling with electric heat units: C, R, G, Y, W.  
For heat pump units: C, R, G, Y, W, B.  
(See page 68 for RT5 T-Stat wiring diagrams)  
During Heat Mode:  
The B terminal must be continuously energized. The W terminal from the T-Stat must have 24 V AC output to call  
for heat. The control board decides on whether to turn on the Heat Pump Heat (compressor) or Electric Resistance  
Heat. The Y terminal should not have 24 VAC output during Heat Mode.  
29  
REMOVING THE FRONT COVER  
REMOVING THE CHASSIS  
WARNING  
WARNING  
ELECTRIC SHOCK HAZARD  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Remove the decorative front cover. (See gure at  
left). Remove the chassis Entrygard Retainer Wire by  
removingthescrewatthefrontrightbottomcornerscrew  
(See Figure below). Save this screw for reattachment  
after reinstalling the chassis.  
Remove the decorative front cover by using the tool  
provided (see gure below).  
Tighten the four (4) captive screws as indicated by the  
arrows in the gure above before closing the front panel  
(do not over tighten). Ensure the lter is in place.  
Make sure curtains do not block the side air intake  
Hold the cabinet stationary then use the hand grips on  
both ends of the control unit support bracket to pull the  
chassis out of the cabinet (see below).  
Notes on reattaching the decorative front cover:  
Align the cord notch over the cord and center the fresh  
air lever. Align the cover over the User Interface  
(UI) to ensure it is clear around it and it does not  
depress any buttons. If not installed correctly the  
wrench alert symbol could ash.  
Before reinserting the chassis into the sleeve ensure to  
properly reinstall the chassis seal gasket.  
30  
REPLACING THE INDOOR COIL  
THERMISTOR  
Replace the indoor coil sensor. Ensure to properly clip  
and insulate it at the same location (see gure below).  
WARNING  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Remove the decorative front cover (see page 30).  
Remove all indicated screws below (8 total, see gure  
below). Remove the Discharge Sensor and the User  
Interface plugs from the control board.  
REPLACING THE CONTROL BOARD  
WARNING  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Remove the decorative front cover (see page 30).  
Disconnect discharge sensor plug (red)  
Disconnect the User Interface plug (white)  
Remove the 3 screws indicated below.  
Pull control board and mount plate out and disconnect  
the following connectors from it:  
Remove the screws indicated at the side and back plate  
(6 total, see gure below). Partially lift the top cover and  
at the same time carefully swing out from the top, the  
back and side plate.  
Power, capacitor, thermistors, fan, reversing valve  
and heater.  
Remove the hex screw holding the control board to  
its mount plate. Pull out the control board (see gure  
below).  
Up  
Swing  
Out  
31  
Low Voltage Interface Connector  
Adding a Remote Wall Thermostat  
An external thermostat may be added to the air conditioner to provide  
remote temperature sensing and control.  
WARNING  
ELECTRIC SHOCK HAZARD  
Thermostat Selection  
Friedrich recommends the use of either the Friedrich RT4 or RT5. These  
thermostats are single stage heat/cool, manual changeover. The RT4 is a  
digital display thermostat with single speed fan control. The RT5 features  
a digital display, two fan speed selection, lter check light, temperature  
limiting, status indicator light, room temperature offset, backlight and  
battery backup. Other thermostats may be used as long as they are single  
stage heat/cool and are congured correctly for the unit.  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
All Kuhl and Kuhl + units have a low voltage interface connector through  
which a Remote Wall Thermostat, Desk Control and Auxiliary Fan’s Relay  
can be connected. The interface connector is located on the left side behind  
the decorative front cover.  
Thermostat terminals requirements:  
For cooling only units: C, R, G, Y.  
For cooling with electric heat units: C, R, G, Y, W.  
For heat pump units: C, R, G, Y, W, B.  
Interface Connector Location  
Figure 1  
For two fan speeds, thermostat must have 2 fan speed selection.  
During Heat Pump Mode:  
The B terminal must be continuously energized. The W terminal must have  
24 VAC output to call for heat. The control board decides on whether to  
turn on the Heat Pump Heat (compressor) or Electric Heat. The Y terminal  
should not have 24 VAC output during heat mode.  
Connecting a Remote Wall  
Thermostat  
Table 1  
Interface Connector Definitions  
Front Panel. Wire jumper between FP and  
F2 enables front panel operation. Jumper off  
enables remote wall t-stat operation.  
FP  
F2  
Used with F1 to provide 24 VAC to external  
fan relay. (See above for use with FP)  
To enable the remote thermostat operation, remove the jumper between  
terminals FP & F2 on the interface connector. Connect the thermostat  
using Figure 1 and Table 1 as a guide.  
Used with F2 to provide 24 VAC to  
external fan relay.  
F1  
D2  
D1  
Procedure  
Used with D1 for desk control on or off  
operation.  
1) Unplug the unit.  
2) Unscrew and remove the decorative front cover. (Page 30)  
Used with D2 for desk control on or off  
operation.  
3) Locate the Interface Connector (24 VAC terminal strip (See gure 1 at  
left) and remove the jumper wire at FP and F2.  
Common Ground Terminal  
Call for high fan  
C
GH  
GL  
B
4) Make the wire connections according to the conguration needed for  
your unit (see above or page 68 for wiring diagrams).  
Call for low fan  
5) Once each wire is matched and connected, the unit is now ready to be  
controlled by the thermostat.  
Call for heat pump reversing valve  
Call for compressor  
6) Reattach the decorative front cover (see page 30).  
Note: Under T-Stat operation the front panel is disabled  
except the Maintenance functions (see page 29 for details).  
Y
W
Call for heating  
R
24V Power from Electronic Control to Wall  
32  
Airflow Selection and Adjustment  
Remote Wall Thermostat Location  
The thermostat should not be mounted where it may be affected by drafts,  
discharge air from registers (hot or cold), or heat radiated from the sun  
appliances, windows etc.. The thermostat should be located about 5 Ft.  
above the oor in an area of average temperature, with good air circulation.  
Air flow direction adjustment  
left or right side of the discharge opening. Each of the banks of louvers  
can be directed left, right, up or down in order to achieve the most optimum  
Mercury bulb type thermostats MUST be level to control temperature  
accurately to the desired set-point. Electronic digital type thermostats  
should be level for aesthetics.  
move it in the direction that you would like the air to be directed. Please  
louvers than the other.  
Fresh air and exhaust control  
Your air conditioner has the ability to bring fresh air into the room or exhaust  
stale air out of the room. The control slide is found on the upper part of  
the unit (See Figure).  
TO BRING IN FRESH AIR – Move the lever to the Fresh Air  
position  
which allows outside air to enter the room. This is useful in fall and spring as  
a means of bringing in fresh outside air when using FAN ONLY . It can also  
be used in the summer with the compressor in the Cooling Mode if you wish.  
TO EXHAUST INDOOR AIR – Move the lever to the Exhaust  
position. This will allow stale air to be expelled to the outside of the dwelling.  
This is especially handy in the spring or fall when indoor air tends to get  
stale, or after a social gathering involving smokers, or to remove cooking  
odors.  
BEST PERFORMANCE – Move the lever to the Re-Circulate Position  
Note: An improperly operating or poorly located remote wall thermostat  
can be the source of perceived equipment problems. A careful check of the  
thermostat’s location and wiring must be made then to ensure that it is not  
the source of problems.  
Desk Control  
The unit’s electronic control has built-in provisions for connection to an  
external switch to control power to the unit. The switch can be a central  
desk control system or even a normally open door switch.  
For desk control operation, connect one side of the switch to the D1  
terminal and the other to the D2 terminal (See page 32). Whenever the  
switch closes, the unit operation will stop.  
Maximum Wire Length for Desk Control Switch  
Auxiliary Fan Control  
The electronic control also has the ability to control a 24 VAC relay to  
activate an auxiliary, or transfer fan. The outputs are listed as F1 and F2 on  
the interface connector (See page 32).  
To connect the relay, simply wire one side of the relay to F1 and the other  
side to F2. Anytime that the fan runs, the terminals will send a 24 VAC  
signal to the relay. The relay must be 24 VAC, 50mA or less.  
Note: The Desk Control, Auxiliary Fan relay and wires must be eld supplied.  
33  
COMPONENTS TESTING  
CAPACITORS  
FAN MOTOR  
A single phase permanent split capacitor motor is used to drive  
the evaporator blower and condenser fan. A self-resetting  
overload is located inside the motor to protect against high  
temperature and high amperage conditions. (See Figure 23)  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before servicing.  
Discharge capacitor with a 20,000 Ohm 2 Watt  
resistor before handling.  
WARNING  
ELECTRIC SHOCK HAZARD  
Failure to do so may result in personal injury,  
or death.  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Many motor capacitors are internally fused. Shorting the  
terminals will blow the fuse, ruining the capacitor. A 20,000  
ohm 2 watt resistor can be used to discharge capacitors  
safely. Remove wires from capacitor and place resistor  
across terminals. When checking a dual capacitor with  
a capacitor analyzer or ohmmeter, both sides must be  
tested.  
BLOWER/FAN MOTOR - TEST  
1. Determine that capacitor is serviceable.  
2. Disconnect fan motor wires from fan speed switch or  
system switch.  
Capacitor Check with Capacitor Analyzer  
3. Apply “live” test cord probes on black wire and common  
terminal of capacitor. Motor should run at high speed.  
The capacitor analyzer will show whether the capacitor is  
“open” or “shorted.” It will tell whether the capacitor is within  
its micro farads rating and it will show whether the capacitor  
is operating at the proper power-factor percentage. The  
instrument will automatically discharge the capacitor when  
the test switch is released.  
4. Apply “live” test cord probes on red wire and common  
terminal of capacitor. Motor should run at low speed.  
5. Apply “live” test cord probes on each of the remaining  
wires from the speed switch or system switch to test  
intermediatespeeds. IfthecontrolisintheMoneySaver”  
mode and the thermostat calls for cooling, the fan will  
start - then stop after approximately 2 minutes; then the  
fan and compressor will start together approximately 2  
minutes later.  
Capacitor Connections  
The starting winding of a motor can be damaged by a  
shorted and grounded running capacitor. This damage  
usually can be avoided by proper connection of the running  
capacitor terminals.  
From the supply line on a typical 230 volt circuit, a 115 volt  
potential exists from the “R” terminal to ground through a  
possible short in the capacitor. However, from the “S” or  
start terminal, a much higher potential, possibly as high as  
400 volts, exists because of the counter EMF generated  
in the start winding. Therefore, the possibility of capacitor  
failure is much greater when the identied terminal is  
connected to the “S” or start terminal. The identied  
terminal should always be connected to the supply line, or  
“R” terminal, never to the “S” terminal.  
Blower/Fan Motor  
When connected properly, a shorted or grounded running  
capacitor will result in a direct short to ground from the “R”  
terminal and will blow the line fuse. The motor protector  
will protect the main winding from excessive temperature.  
Dual Rated Run Capacitor Hook-up  
34  
COMPONENTS TESTING  
HEATING ELEMENT  
TESTING THE HEATING ELEMENT  
All heat pumps and electric heat models are equipped  
with a heating element with the exception of model  
YS10M10. The other “YS” and “ES” models are  
equipped with a 3.3 KW element. The “YM” and “EM”  
models are equipped with a 4.0 KW element. The  
“YL” and “EL” models are equipped with a 5.2 KW  
element.  
WARNING  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before  
servicing. Failure to follow this warning  
could result in serious injury or death.  
Testing of the elements can be made with an ohmmeter  
across the terminals after the connecting wires  
have been removed. A cold resistance reading of  
approximately 14.5 ohms for the 3.3 KW heater, 11.9  
ohms for the 4.0 KW heater and 9.15 ohms for the 5.2  
KW heater should be registered.  
Heating Element  
Sample  
DRAIN PAN VALVE  
During the cooling mode of operation, condensate  
which collects in the drain pan is picked up by the con-  
denser fan blade and sprayed onto the condenser coil.  
This assists in cooling the refrigerant plus evaporating  
the water.  
The heating element contains a fuse link and a heater  
limit switch. The fuse link is in series with the power  
supply and will open and interrupt the power when the  
temperature reaches 199°F or a short circuit occurs in  
the heating element. Once the fuse link separates, a  
new fuse link must be installed.  
During the heating mode of operation, it is necessary  
that water be removed to prevent it from freezing during  
cold outside temperatures. This could cause the con-  
denser fan blade to freeze in the accumulated water  
and prevent it from turning.  
NOTE:  
Always replace with the exact  
replacement.  
The heater element has a high limit control. This  
control is a bimetal thermostat mounted in the top of  
the heating element.  
To provide a means of draining this water, a bellows  
type drain valve is installed over a drain opening in the  
base pan.  
Should the fan motor fail or lter become clogged,  
the high limit control will open and interrupt power to  
the heater before reaching an unsafe temperature  
condition.  
This valve is temperature sensitive and will open when  
the outside temperature reaches 40°F. The valve will  
close gradually as the temperature rises above 40°F to  
fully close at 60°F.  
The control is designed to open at 110°F ±6°F. Test  
continuity below 110°F and for open above 110°F.  
Bellows Assembly  
Drain Pan Valve  
HEATING ELEMENT (Heat Pump Models)  
The heating element for the “Y” model is energized  
by an outdoor thermistor via the electronic control  
board. The outdoor defrost thermistor is adjusted at  
a predetermined temperature to bring on the heating  
element and turn off the compressor. The room  
35  
REFRIGERATION SEQUENCE OF OPERATION  
A good understanding of the basic operation of the  
refrigeration system is essential for the service technician.  
Without this understanding, accurate troubleshooting of  
refrigeration system problems will be more difcult and time  
consuming, if not (in some cases) entirely impossible. The  
refrigeration system uses four basic principles (laws) in its  
operation they are as follows:  
The refrigerant leaves the condenser Coil through the liquid  
line as a warm high pressure liquid. It next will pass through  
the refrigerant drier (if so equipped). It is the function of the  
driertotrapanymoisturepresentinthesystem,contaminants,  
and large particulate matter.  
The liquid refrigerant next enters the metering device. The  
metering device is a capillary tube. The purpose of the  
metering device is to “meter” (i.e. control or measure) the  
quantity of refrigerant entering the evaporator coil.  
1. “Heat always ows from a warmer body to a cooler  
body.”  
2. “Heat must be added to or removed from a substance  
before a change in state can occur”  
In the case of the capillary tube this is accomplished (by  
design) through size (and length) of device, and the pressure  
difference present across the device.  
3. “Flow is always from a higher pressure area to a lower  
pressure area.”  
Since the evaporator coil is under a lower pressure (due to  
the suction created by the compressor) than the liquid line,  
the liquid refrigerant leaves the metering device entering the  
evaporator coil. As it enters the evaporator coil, the larger  
area and lower pressure allows the refrigerant to expand  
and lower its temperature (heat intensity). This expansion is  
often referred to as “boiling”. Since the unit’s blower is moving  
indoor air across the nned surface of the evaporator coil,  
the expanding refrigerant absorbs some of that heat. This  
results in a lowering of the indoor air temperature, hence the  
“cooling” effect.  
4. “The temperature at which a liquid or gas changes state  
is dependent upon the pressure.”  
The refrigeration cycle begins at the compressor. Starting  
the compressor creates a low pressure in the suction line  
which draws refrigerant gas (vapor) into the compressor.  
The compressor then “compresses” this refrigerant, raising  
its pressure and its (heat intensity) temperature.  
The refrigerant leaves the compressor through the discharge  
Line as a hot High pressure gas (vapor). The refrigerant  
enters the condenser coil where it gives up some of its  
heat. The condenser fan moving air across the coil’s nned  
surface facilitates the transfer of heat from the refrigerant to  
the relatively cooler outdoor air.  
The expansion and absorbing of heat cause the liquid  
refrigerant to evaporate (i.e. change to a gas). Once the  
refrigerant has been evaporated (changed to a gas), it is  
heated even further by the air that continues to ow across  
the evaporator coil.  
When a sufcient quantity of heat has been removed from  
the refrigerant gas (vapor), the refrigerant will “condense”  
(i.e. change to a liquid). Once the refrigerant has been  
condensed (changed) to a liquid it is cooled even further by  
the air that continues to ow across the condenser coil.  
The particular system design determines at exactly what  
point (in the evaporator) the change of state (i.e. liquid to a  
gas) takes place. In all cases, however, the refrigerant must  
be totally evaporated (changed) to a gas before leaving the  
evaporator coil.  
The RAC design determines at exactly what point (in the  
condenser) the change of state (i.e. gas to a liquid) takes  
place. In all cases, however, the refrigerant must be  
totally condensed (changed) to a Liquid before leaving the  
condenser coil.  
The low pressure (suction) created by the compressor  
causes the refrigerant to leave the evaporator through the  
suction line as a cool low pressure vapor. The refrigerant then  
returns to the compressor, where the cycle is repeated.  
Suction  
Line  
Discharge  
Line  
Condenser  
Coil  
Evaporator  
Coil  
Compressor  
Metering  
Device  
Refrigerant Drier  
Liquid  
Line  
Refrigerant  
Strainer  
36  
R-410A SEALED SYSTEM REPAIR CONSIDERATIONS  
WARNING  
Refrigeration system under high pressure  
Do not puncture, heat, expose to ame or incinerate.  
Only certied refrigeration technicians should  
service this equipment.  
R410A systems operate at higher pressures than  
R22 equipment. Appropriate safe service and  
handling practicces must be used.  
Only use gauge sets designed for use with R410A.  
Do not use standard R22 gauge sets.  
The following is a list of important considerations when working with R-410A equipment  
R-410A pressure is approximately 60% higher than R-22 pressure.  
R-410A cylinders must not be allowed to exceed 125 F, they may leak or rupture.  
R-410A must never be pressurized with a mixture of air, it may become  
ammable.  
Servicing equipment and components must be specically designed for use with R-410A and  
dedicated to prevent contamination.  
Manifold sets must be equipped with gauges capable of reading 750 psig (high side) and 200  
psig (low side), with a 500-psig low-side retard.  
Gauge hoses must have a minimum 750-psig service pressure rating  
Recovery cylinders must have a minimum service pressure rating of 400 psig, (DOT 4BA400  
and DOT BW400 approved cylinders).  
POE (Polyol-Ester) lubricants must be used with R-410A equipment.  
To prevent moisture absorption and lubricant contamination, do not leave the refrigeration  
system open to the atmosphere longer than 1 hour.  
Weigh-in the refrigerant charge into the high side of the system.  
Introduce liquid refrigerant charge into the high side of the system.  
For low side pressure charging of R-410A, use a charging adaptor.  
Use Friedrich approved R-410A lter dryers only.  
37  
R-410A SEALED REFRIGERATION SYSTEM REPAIRS  
IMPORTANT  
SEALED SYSTEM REPAIRS TO COOL-ONLY MODELS REQUIRE THE INSTALLATION OF A LIQUID LINE DRIER.  
EQUIPMENT REQUIRED:  
9. High Pressure Gauge - (0 to 750 lbs.)  
10. Low Pressure Gauge - (-30 to 200 lbs.)  
11. Vacuum Gauge - (0 - 1000 microns)  
1. Voltmeter  
2. Ammeter  
3. Ohmmeter  
12. Facilities for owing nitrogen through refrigeration tubing  
4. E.P.A. Approved Refrigerant Recovery System  
during all brazing processes.  
5. Vacuum Pump (capable of 200 microns or less  
vacuum.)  
EQUIPMENT MUST BE CAPABLE OF:  
6. Acetylene Welder  
1. Recovering refrigerant to EPA required levels.  
7. Electronic Halogen Leak Detector capable of  
2. Evacuation from both the high side and low side of the  
system simultaneously.  
detecting HFC (Hydrouorocarbon) refrigerants.  
8. Accurate refrigerant charge measuring device such  
as:  
3. Introducing refrigerant charge into high side of the  
system.  
a. Balance Scales - 1/2 oz. accuracy  
b. Charging Board - 1/2 oz. accuracy  
4. Accurately weighing the refrigerant charge introduced  
into the system.  
Proper refrigerant charge is essential to proper unit operation.  
Operating a unit with an improper refrigerant charge will  
result in reduced performance (capacity) and/or efciency.  
Accordingly, the use of proper charging methods during  
servicing will insure that the unit is functioning as designed  
and that its compressor will not be damaged.  
WARNING  
RISK OF ELECTRIC SHOCK  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
Failure to do so could result in electric shock,  
serious injury or death.  
Too much refrigerant (overcharge) in the system is just as bad  
(if not worse) than not enough refrigerant (undercharge). They  
both can be the source of certain compressor failures if they  
remain uncorrected for any period of time. Quite often, other  
problems (such as low air ow across evaporator, etc.) are  
misdiagnosed as refrigerant charge problems. The refrigerant  
circuit diagnosis chart will assist you in properly diagnosing  
these systems.  
WARNING  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
An overcharged unit will at times return liquid refrigerant  
(slugging) back to the suction side of the compressor eventually  
causing a mechanical failure within the compressor. This  
mechanical failure can manifest itself as valve failure, bearing  
failure, and/or other mechanical failure. The specic type of  
failure will be inuenced by the amount of liquid being returned,  
and the length of time the slugging continues.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow these procedures could  
result in serious injury or death.  
Refrigerant Charging  
Not enough refrigerant (undercharge) on the other hand, will  
cause the temperature of the suction gas to increase to the point  
where it does not provide sufcient cooling for the compressor  
motor. When this occurs, the motor winding temperature will  
increase causing the motor to overheat and possibly cycle open  
the compressor overload protector. Continued overheating of  
the motor windings and/or cycling of the overload will eventually  
lead to compressor motor or overload failure.  
NOTE: Because the RAC system is a sealed system, service  
process tubes will have to be installed. First install a line tap  
and remove refrigerant from system. Make necessary sealed  
system repairs and vacuum system. Crimp process tube  
line and solder end shut. Do not leave a service valve in the  
sealed system.  
38  
Method Of Charging / Repairs  
The acceptable method for charging the WallMaster system  
is the Weighed in Charge Method. The weighed in charge  
method is applicable to all units. It is the preferred method to  
use, as it is the most accurate.  
The weighed in method should always be used whenever  
a charge is removed from a unit such as for a leak repair,  
compressor replacement, or when there is no refrigerant  
charge left in the unit. To charge by this method, requires the  
following steps:  
1. Install a piercing valve to remove refrigerant from the  
sealedsystem. (Piercing valve must be removed from the  
system before recharging.)  
2. Recover Refrigerant in accordance with EPA regulations.  
WARNING  
BURN HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
Failure to follow these procedures could  
result in moderate or serious injury.  
3. Install a process tube to sealed system.  
CAUTION  
FREEZE HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with liquid refrigerant.  
Failure to follow these procedures could  
result in minor to moderate injury.  
4. Make necessary repairs to system.  
5. Evacuate system to 200 microns or less.  
6. Weigh in refrigerant with the property quantity of R-410A  
refrigerant.  
7. Start unit, and verify performance.  
WARNING  
BURN HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
Failure to follow these procedures could  
result in moderate or serious injury.  
8. Crimp the process tube and solder the end shut.  
39  
WARNING  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
Extreme care must be used, if it becomes  
necessary to work on equipment with power  
applied.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to do so could result in serious injury or  
death.  
Failure to follow these procedures could  
result in serious injury or death.  
Undercharged Refrigerant Systems  
An undercharged system will result in poor performance  
(low pressures, etc.) in both the heating and cooling  
cycle.  
A check of the amperage drawn by the compressor  
motor should show a lower reading. (Check the Unit  
Specication.) After the unit has run 10 to 15 minutes,  
check the gauge pressures. Gauges connected to system  
with an undercharge will have low head pressures and  
substantially low suction pressures.  
Whenever you service a unit with an undercharge of  
refrigerant, always suspect a leak. The leak must be  
repaired before charging the unit.  
To check for an undercharged system, turn the unit on,  
allow the compressor to run long enough to establish  
working pressures in the system (15 to 20 minutes).  
During the cooling cycle you can listen carefully at the exit  
of the metering device into the evaporator; an intermittent  
hissing and gurgling sound indicates a low refrigerant  
charge. Intermittent frosting and thawing of the evaporator  
is another indication of a low charge, however, frosting  
and thawing can also be caused by insufcient air over  
the evaporator.  
Checks for an undercharged system can be made at  
the compressor. If the compressor seems quieter than  
normal, it is an indication of a low refrigerant charge.  
of the evaporator will not be encountered because the  
refrigerant will boil later if at all. Gauges connected to  
system will usually have higher head pressure (depending  
upon amount of over charge). Suction pressure should be  
slightly higher.  
Overcharged Refrigerant Systems  
Compressor amps will be near normal or higher.  
Noncondensables can also cause these symptoms. To  
conrm, remove some of the charge, if conditions improve,  
system may be overcharged. If conditions don’t improve,  
Noncondensables are indicated.  
Whenever an overcharged system is indicated, always  
make sure that the problem is not caused by air ow  
problems. Improper air ow over the evaporator coil may  
indicate some of the same symptoms as an over charged  
system.  
An overcharge can cause the compressor to fail, since it  
would be “slugged” with liquid refrigerant.  
Thechargeforanysystemiscritical. Whenthecompressor  
is noisy, suspect an overcharge, when you are sure that  
the air quantity over the evaporator coil is correct. Icing  
40  
Restricted Refrigerant System  
Troubleshooting a restricted refrigerant system can be  
difcult. The following procedures are the more common  
problems and solutions to these problems. There are two  
types of refrigerant restrictions: Partial restrictions and  
complete restrictions.  
at the metering device entrance to the evaporator. The  
evaporator in a partial restriction could be partially frosted  
or have an ice ball close to the entrance of the metering  
device. Frost may continue on the suction line back to the  
compressor.  
A partial restriction allows some of the refrigerant to  
circulate through the system.  
Often a partial restriction of any type can be found by feel,  
as there is a temperature difference from one side of the  
restriction to the other.  
With a complete restriction there is no circulation of  
refrigerant in the system.  
With a complete restriction, there will be no sound at the  
metering device entrance. An amperage check of the  
compressor with a partial restriction may show normal  
current when compared to the unit specication. With a  
complete restriction the current drawn may be considerably  
less than normal, as the compressor is running in a deep  
vacuum (no load.) Much of the area of the condenser will  
be relatively cool since most or all of the liquid refrigerant  
will be stored there.  
Restricted refrigerant systems display the same symptoms  
as a “low-charge condition.”  
When the unit is shut off, the gauges may equalize very  
slowly.  
Gauges connected to a completely restricted system will  
run in a deep vacuum. When the unit is shut off, the gauges  
will not equalize at all.  
The following conditions are based primarily on a system  
in the cooling mode.  
A quick check for either condition begins at the evaporator.  
With a partial restriction, there may be gurgling sounds  
41  
HERMETIC COMPONENTS CHECK  
WARNING  
BURN HAZARD  
WARNING  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with a torch.  
CUT/SEVER HAZARD  
Be careful with the sharp edges and corners.  
Wear protective clothing and gloves, etc.  
Failure to follow these procedures could  
result in moderate or serious injury.  
Failure to do so could result in serious injury.  
METERING DEVICE  
Capillary Tube Systems  
All units are equipped with capillary tube metering  
devices.  
3. Switch the unit to the heating mode and observe the  
gauge readings after a few minutes running time. If  
the system pressure is lower than normal, the heating  
capillary is restricted.  
Checking for restricted capillary tubes.  
1. Connect pressure gauges to unit.  
4. If the operating pressures are lower than normal in both  
the heating and cooling mode, the cooling capillary is  
restricted.  
2. Start the unit in the cooling mode. If after a few minutes  
of operation the pressures are normal, the check valve  
and the cooling capillary are not restricted.  
CHECK VALVE  
In the heating mode of operation, high pressure refrigerant  
enters the check valve from the opposite direction, closing  
the port (liquid line) to the outdoor coil. The ow path of  
the refrigerant is then through the lter drier and heating  
capillary to the outdoor coil.  
A unique two-way check valve is used on the reverse cycle  
heat pumps. It is pressure operated and used to direct the  
ow of refrigerant through a single lter drier and to the  
proper capillary tube during either the heating or cooling  
cycle.  
Failure of the slide in the check valve to seat properly in  
either mode of operation will cause ooding of the cooling  
coil. This is due to the refrigerant bypassing the heating or  
cooling capillary tube and entering the liquid line.  
One-way Check Valve  
(Heat Pump Models)  
COOLING MODE  
In the cooling mode of operation, liquid refrigerant from  
condenser (liquid line) enters the cooling check valve  
forcing the heating check valve shut. The liquid refrigerant  
is directed into the liquid dryer after which the refrigerant  
is metered through cooling capillary tubes to evaporator.  
(Note: liquid refrigerant will also be directed through the  
heating capillary tubes in a continuous loop during the  
cooling mode).  
NOTE: The slide (check) inside the valve is made of teon.  
Should it become necessary to replace the check valve,  
place a wet cloth around the valve to prevent overheating  
during the brazing operation.  
CHECK VALVE OPERATION  
HEATING MODE  
In the cooling mode of operation, high pressure liquid enters  
the check valve forcing the slide to close the opposite port  
(liquid line) to the indoor coil. Refer to refrigerant ow chart.  
This directs the refrigerant through the lter drier and cooling  
capillary tube to the indoor coil.  
In the heating mode of operation, liquid refrigerant from  
the indoor coil enters the heating check valve forcing the  
cooling check valve shut. The liquid refrigerant is directed  
into the liquid dryer after which the refrigerant is metered  
through the heating capillary tubes to outdoor coils. (Note:  
liquid refrigerant will also be directed through the cooling  
capillary tubes in a continuous loop during the heating  
mode).  
42  
REVERSING VALVE DESCRIPTION/OPERATION  
WARNING  
ELECTRIC SHOCK HAZARD  
Disconnect power to the unit before servicing.  
Failure to follow this warning could result in  
serious injury or death.  
The Reversing Valve controls the direction of refrigerant  
“AandBportsofthepilotvalve.Athirdcapillaryisacommon  
return line from these ports to the suction tube on the main  
valve body. Four-way reversing valves also have a capillary  
tube from the compressor discharge tube to the pilot valve.  
ow to the indoor and outdoor coils. It consists of a  
pressure-operated, main valve and a pilot valve actuated  
by a solenoid plunger. The solenoid is energized during the  
heating cycle only. The reversing valves used in the RAC  
system is a 2-position, 4-way valve.  
The piston assembly in the main valve can only be shifted  
by the pressure differential between the high and low sides  
of the system. The pilot section of the valve opens and  
closes ports for the small capillary tubes to the main valve  
to cause it to shift.  
The single tube on one side of the main valve body is the  
high-pressure inlet to the valve from the compressor. The  
center tube on the opposite side is connected to the low  
pressure (suction) side of the system. The other two are  
connected to the indoor and outdoor coils. Small capillary  
tubes connect each end of the main valve cylinder to the  
NOTE: System operating pressures must be near  
normal before valve can shift.  
43  
TESTING THE REVERSING VALVE  
SOLENOID COIL  
Should the valve fail to shift from coooling to heating,  
block the air ow through the outdoor coil and allow the  
discharge pressure to build in the system. Then switch  
the system from heating to cooling.  
WARNING  
ELECTRIC SHOCK HAZARD  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
If the valve is stuck in the heating position, block the air  
ow through the indoor coil and allow discharge pressure  
to build in the system. Then switch the system from  
heating to cooling.  
Failure to do so could result in electric shock,  
serious injury or death.  
Should the valve fail to shift in either position after  
increasing the discharge pressure, replace the valve.  
The solenoid coil is an electromagnetic type coil mounted  
on the reversing valve and is energized during the  
operation of the compressor in the heating cycle.  
Dented or damaged valve body or capillary tubes can  
prevent the main slide in the valve body from shifting.  
1. Turn off high voltage electrical power to unit.  
2. Unplug line voltage lead from reversing valve coil.  
If you determing this is the problem, replace the reversing  
valve.  
3. Check for electrical continuity through the coil. If you  
do not have continuity replace the coil.  
After all of the previous inspections and checks have  
been made and determined correct, then perform the  
Touch Test” on the reversing valve.  
4. Check from each lead of coil to the copper liquid line  
as it leaves the unit or the ground lug. There should  
be no continuity between either of the coil leads  
and ground; if there is, coil is grounded and must be  
replaced.  
5. If coil tests okay, reconnect the electrical leads.  
6. Make sure coil has been assembled correctly.  
NOTE: Do not start unit with solenoid coil removed from  
valve, or do not remove coil after unit is in operation. This  
will cause the coil to burn out.  
CHECKING THE REVERSING VALVE  
NOTE: You must have normal operating pressures before  
the reversing valve can shift.  
WARNING  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
Reversing Valve in Heating Mode  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow these procedures could  
result in serious injury or death.  
Check the operation of the valve by starting the system  
and switching the operation from “Cooling” to “Heating”  
and then back to “Cooling”. Do not hammer on valve.  
Occasionally, the reversing valve may stick in the heating  
or cooling position or in the mid-position.  
When sluggish or stuck in the mid-position, part of the  
discharge gas from the compressor is directed back to the  
suction side, resulting in excessively high suction pressure.  
44  
Touch Test in Heating/Cooling Cycle  
6. Protectnewvalvebodyfromheatwhilebrazingwith plastic  
heat sink (Thermo Trap) or wrap valve body with wet  
rag.  
WARNING  
BURN HAZARD  
Certain unit components operate at  
temperatures hot enough to cause burns.  
7. Fit all lines into new valve and braze lines into new  
valve.  
Proper safety procedures must be followed,  
and proper protective clothing must be  
worn.  
WARNING  
EXPLOSION HAZARD  
Failure to follow these procedures could  
result in minor to moderate injury.  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
The only definite indications that the slide is in the mid-  
position is if all three tubes on the suction side of the valve  
are hot after a few minutes of running time.  
Failure to follow proper safety procedures  
could result in serious injury or death.  
8. Pressurize sealed system with a combination of R-410A  
and nitrogen and check for leaks, using a suitable leak  
detector. Recover refrigerant per EPA guidelines.  
NOTE: A condition other than those illustrated above, and  
on Page 44, indicate that the reversing valve is not shifting  
properly. Both tubes shown as hot or cool must be the same  
corresponding temperature.  
9. Once the sealed system is leak free, install solenoid coil  
on new valve and charge the sealed system by weighing  
in the proper amount and type of refrigerant as shown  
on rating plate. Crimp the process tubes and solder the  
ends shut. Do not leave Schrader or piercing valves in  
the sealed system.  
Procedure For Changing Reversing Valve  
WARNING  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
NOTE: When brazing a reversing valve into the system, it is  
of extreme importance that the temperature of the valve does  
not exceed 250°F at any time.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Wrap the reversing valve with a large rag saturated with  
water. “Re-wet” the rag and thoroughly cool the valve after  
each brazing operation of the four joints involved.  
Failure to follow these procedures could  
result in serious injury or death.  
The wet rag around the reversing valve will eliminate  
conduction of heat to the valve body when brazing the line  
connection.  
NOTICE  
FIRE HAZARD  
The use of a torch requires extreme care and proper  
judgment. Follow all safety recommended precautions  
and protect surrounding areas with re proof materials.  
Have a re extinguisher readily available. Failure to follow  
this notice could result in moderate to serious property  
damage.  
1. Install Process Tubes. Recover refrigerant from sealed  
system. PROPER HANDLING OF RECOVERED  
REFRIGERANT ACCORDING TO EPA REGULATIONS  
IS REQUIRED.  
2. Remove solenoid coil from reversing valve. If coil is to  
be reused, protect from heat while changing valve.  
3. Unbraze all lines from reversing valve.  
4. Clean all excess braze from all tubing so that they will  
slip into ttings on new valve.  
5. Remove solenoid coil from new valve.  
45  
COMPRESSOR CHECKS  
Heat generated within the compressor shell, usually due  
to recycling of the motor, is slow to dissipate. It may take  
anywhere from a few minutes to several hours for the  
overload to reset.  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment with  
power applied.  
Checking the Overloads  
Failure to do so could result in serious injury or  
death.  
WARNING  
ELECTRIC SHOCK HAZARD  
Locked Rotor Voltage (L.R.V.) Test  
Turn off electric power before service or  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment  
with power applied.  
Locked rotor voltage (L.R.V.) is the actual voltage available  
at the compressor under a stalled condition.  
Single Phase Connections  
Failure to do so could result in serious injury or  
death.  
Disconnect power from unit. Using a voltmeter, attach one  
lead of the meter to the run “R” terminal on the compressor  
and the other lead to the common “C” terminal of the com-  
pressor. Restore power to unit.  
WARNING  
BURN HAZARD  
Certain unit components operate at  
temperatures hot enough to cause burns.  
Determine L.R.V.  
Start the compressor with the volt meter attached; then stop  
the unit. Attempt to restart the compressor within a couple  
of seconds and immediately read the voltage on the meter.  
The compressor under these conditions will not start and will  
usually kick out on overload within a few seconds since the  
pressures in the system will not have had time to equalize.  
Voltage should be at or above minimum voltage of 197 VAC,  
as specied on the rating plate. If less than minimum, check  
for cause of inadequate power supply; i.e., incorrect wire  
size, loose electrical connections, etc.  
Proper safety procedures must be followed,  
and proper protective clothing must be  
worn.  
Failure to follow this warning could result  
in moderate to serious injury.  
External Overloads  
With power off, remove the leads from compressor  
terminals. If the compressor is hot, allow the overload  
to cool before starting check. Using an ohmmeter, test  
continuity across the terminals of the external overload.  
If you do not have continuity; this indicates that the  
overload is open and must be replaced.  
Amperage (L.R.A.) Test  
The running amperage of the compressor is the most  
important of these readings. A running amperage higher  
than that indicated in the performance data indicates that a  
problem exists mechanically or electrically.  
Interrnal Overloads  
Some model compressors are equipped with an internal  
overload. The overload is embedded in the motor  
windings to sense the winding temperature and/or current  
draw. The overload is connected in series with the  
common motor terminal.  
Single Phase Running and L.R.A. Test  
NOTE: Consult the specication and performance section  
for running amperage. The L.R.A. can also be found on the  
rating plate.  
Select the proper amperage scale and clamp the meter  
probe around the wire to the “C” terminal of the compressor.  
Should the internal temperature and/or current draw  
become excessive, the contacts in the overload will  
open, turning off the compressor. The overload will  
automatically reset, but may require several hours before  
the heat is dissipated.  
Turn on the unit and read the running amperage on the  
meter. If the compressor does not start, the reading will  
indicate the locked rotor amperage (L.R.A.).  
Checking the Internal Overload  
1. With no power to unit, remove the leads from the  
compressor terminals.  
2. Using an ohmmeter, test continuity between terminals  
C-S and C-R. If no continuity, the compressor overload is  
open and the compressor must be replaced.  
Overloads  
The compressor is equipped with either an external or  
internal overload which senses both motor amperage  
and winding temperature. High motor temperature or  
amperage heats the overload causing it to open, breaking  
the common circuit within the compressor.  
46  
Single Phase Resistance Test  
Many compressor failures are caused by the following  
conditions:  
WARNING  
ELECTRIC SHOCK HAZARD  
1. Improper air ow over the evaporator.  
Turn off electric power before service or  
2. Overcharged refrigerant system causing liquid to be  
returned to the compressor.  
installation. Extreme care must be used, if it  
becomes necessary to work on equipment  
with power applied.  
3. Restricted refrigerant system.  
4. Lack of lubrication.  
Failure to do so could result in serious injury or  
death.  
Remove the leads from the compressor terminals and set  
the ohmmeter on the lowest scale (R x 1).  
5. Liquid refrigerant returning to compressor causing oil  
to be washed out of bearings.  
Touch the leads of the ohmmeter from terminals common  
to start (“C” to “S”). Next, touch the leads of the ohmmeter  
from terminals common to run (“C” to “R”).  
6.  
Noncondensables such as air and moisture in  
the system. Moisture is extremely destructive to a  
refrigerant system.  
Add values “C” to “S” and “C” to “R” together and  
check resistance from start to run terminals (“S” to “R”).  
Resistance “S” to “R” should equal the total of “C” to “S”  
and “C” to “R.”  
7. Capacitor (see page 34).  
CHECKING COMPRESSOR EFFICIENCY  
In a single phase PSC compressor motor, the highest  
value will be from the start to the run connections (“S” to  
“R”). The next highest resistance is from the start to the  
common connections (“S” to “C”). The lowest resistance  
is from the run to common. (“C” to “R”) Before replacing a  
compressor, check to be sure it is defective.  
The reason for compressor inefciency is normally due  
to broken or damaged suction and/or discharge valves,  
reducing the ability of the compressor to pump refrigerant  
gas.  
WARNING  
HIGH PRESSURE HAZARD  
GROUND TEST  
Use an ohmmeter set on its highest scale. Touch one  
lead to the compressor body (clean point of contact as  
a good connection is a must) and the other probe in turn  
to each compressor terminal. If a reading is obtained the  
compressor is grounded and must be replaced.  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Check the complete electrical system to the compressor  
and compressor internal electrical system, check to be  
certain that compressor is not out on internal overload.  
Failure to follow these procedures could  
result in serious injury or death.  
This condition can be checked as follows:  
Complete evaluation of the system must be made  
whenever you suspect the compressor is defective. If  
the compressor has been operating for sometime, a  
careful examination must be made to determine why the  
compressor failed.  
1. Install a piercing valve on the suction and discharge or  
liquid process tube.  
-
2. Attach gauges to the high and low sides of the system.  
3. Start the system and run a “cooling or heating perfor  
mance test.” If test shows:  
A. Below normal high side pressure  
B. Above normal low side pressure  
C. Low temperature difference across coil  
The compressor valves are faulty - replace the  
compressor.  
47  
COMPRESSOR REPLACEMENT  
Recommendedprocedureforcompressor  
replacement  
3. After all refrigerant has been recovered, disconnect  
suction and discharge lines from the compressor and  
remove compressor. Be certain to have both suction  
and discharge process tubes open to atmosphere.  
WARNING  
4. Carefully pour a small amount of oil from the suction  
RISK OF ELECTRIC SHOCK  
Unplug and/or disconnect all electrical power  
to the unit before performing inspections,  
maintenances or service.  
stub of the defective compressor into a clean  
container.  
5. Using an acid test kit (one shot or conventional kit), test  
the oil for acid content according to the instructions  
with the kit.  
Failure to do so could result in electric shock,  
serious injury or death.  
6. If any evidence of a burnout is found, no matter how  
slight, the system will need to be cleaned up following  
proper procedures.  
1. Be certain to perform all necessary electrical and  
refrigeration tests to be sure the compressor is  
actually defective before replacing.  
7. Install the replacement compressor.  
WARNING  
WARNING  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
EXPLOSION HAZARD  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow proper safety procedures  
result in serious injury or death.  
Failure to follow these procedures could  
result in serious injury or death.  
8. Pressurize with a combination of R-410A and nitrogen  
and leak test all connections with an electronic or  
Halide leak detector. Recover refrigerant and repair  
any leaks found.  
2. Recover all refrigerant from the system though  
the process tubes. PROPER HANDLING OF  
RECOVERED REFRIGERANT ACCORDING TO  
EPA REGULATIONS IS REQUIRED. Do not use  
gauge manifold for this purpose if there has been  
a burnout. You will contaminate your manifold and  
hoses. Use a Schrader valve adapter and copper  
tubing for burnout failures.  
Repeat Step 8 to insure no more leaks are present.  
9. Evacuate the system with a good vacuum pump capable  
of a nal vacuum of 200 microns or less. The system  
should be evacuated through both liquid line and suction  
line gauge ports. While the unit is being evacuated, seal  
all openings on the defective compressor. Compressor  
manufacturers will void warranties on units received not  
properly sealed. Do not distort the manufacturers tube  
connections.  
WARNING  
HIGH TEMPERATURES  
Extreme care, proper judgment and all safety  
procedures must be followed when testing,  
troubleshooting, handling or working around  
unit while in operation with high temperature  
components. Wear protective safety aids  
such as: gloves, clothing etc.  
CAUTION  
FREEZE HAZARD  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with liquid refrigerant.  
Failure to do so could result in serious burn  
injury.  
Failure to follow these procedures could  
result in minor to moderate injury.  
NOTICE  
FIRE HAZARD  
10. Recharge the system with the correct amount of  
refrigerant. The proper refrigerant charge will be  
found on the unit rating plate. The use of an accurate  
measuring device, such as a charging cylinder,  
The use of a torch requires extreme care and proper  
judgment. Follow all safety recommended precautions  
and protect surrounding areas with re proof materials.  
Have a re extinguisher readily available. Failure to follow  
this notice could result in moderate to serious property  
damage.  
electronic scales or similar device is necessary.  
48  
SPECIAL PROCEDURE IN THE CASE OF MOTOR  
COMPRESSOR BURNOUT  
WARNING  
ELECTRIC SHOCK HAZARD  
Turn off electric power before service or  
installation.  
Failure to do so may result in personal injury,  
or death.  
WARNING  
HIGH PRESSURE HAZARD  
Sealed Refrigeration System contains refrigerant  
and oil under high pressure.  
Proper safety procedures must be followed,  
and proper protective clothing must be worn  
when working with refrigerants.  
Failure to follow these procedures could  
result in serious injury or death.  
WARNING  
EXPLOSION HAZARD  
The use of nitrogen requires a pressure  
regulator. Follow all safety procedures and  
wear protective safety clothing etc.  
Failure to follow proper safety procedures  
result in serious injury or death.  
1.  
2.  
Recover all refrigerant and oil from the system.  
Remove compressor, capillary tube and lter drier  
from the system.  
3.  
Flush evaporator condenser and all connecting  
tubing with dry nitrogen or equivalent. Use approved  
ushing agent to remove all contamination from  
system. Inspect suction and discharge line for  
carbon deposits. Remove and clean if necessary.  
Ensure all acid is neutralized.  
4. Reassemble the system, including new drier strainer  
and capillary tube.  
5. Proceed with step 8-10 on previous page.  
ROTARY AND SCROLL COMPRESSOR SPECIAL  
TROUBLESHOOTING AND SERVICE  
Basically, troubleshooting and servicing rotary compres-  
sors is the same as on the reciprocating compressor with  
only one main exception:  
NEVER, under any circumstances, liquid charge a rotary-  
compressor through the LOW side. Doing so would cause  
permanent damage to the new compressor.  
49  
ROUTINE MAINTENANCE  
COILS AND BASE PAN  
WARNING  
The indoor coil (evaporator coil), the outdoor coil  
(condenser coil) and base pan should be inspected  
periodically (yearly or bi-yearly) and cleaned of all  
debris (lint, dirt, leaves, paper, etc.). Clean the coils  
and base pan with a soft brush and compressed air  
or vacuum. If using a pressure washer, be careful  
not to bend the aluminium n pack. Use a sweeping  
up and down motion in the direction of the vertical  
aluminum n pack when pressure cleaning coils.  
Cover all electrical components to protect them from  
water or spray. Allow the unit to dry thoroughly before  
reinstalling it in the sleeve.  
ELECTRIC SHOCK HAZARD  
Turn off electric power before inspections,  
maintenances, or service.  
Extreme care must be used, if it becomes  
necessary to work on equipment with power  
applied.  
Failure to do so could result in serious injury  
or death.  
NOTE: Do not use a caustic coil cleaning agent on coils or base pan.  
Use a biodegradable cleaning agent and degreaser. The use  
of harsh c leaning materials may lead to deterioration of the  
WARNING  
EXCESSIVE WEIGHT HAZARD  
Use two people to lift or carry the unit, and wear  
proper protective clothing.  
NOTE: It is extremely important to insure that none of the electrical  
and/or electronic parts of the unit get wet. Be sure to cover all  
electrical components to protect them from water or spray.  
Failure to do so may result in personal injury.  
BLOWER WHEEL / HOUSING / CONDENSER FAN /  
SHROUD  
WARNING  
Inspect the indoor blower and its housing, evaporator  
blade, condenser fan blade and condenser shroud  
periodically (yearly or bi-yearly) and clean of all debris  
(lint, dirt, mold, fungus, etc.). Clean the blower housing  
area and blower wheel with an antibacterial / antifungal  
cleaner. Use a biodegradable cleaning agent and  
degreaser on condenser fan and condenser shroud.  
Use warm or cold water when rinsing these items.  
Allow all items to dry thoroughly before reinstalling  
them.  
CUT/SEVER HAZARD  
Be careful with the sharp edges and corners.  
Wear protective clothing and gloves, etc.  
Failure to do so could result in serious injury.  
NOTICE  
Units are to be inspected and serviced by qualied service  
personnel only. Use proper protection on surrounding  
property. Failure to follow this notice could result in  
moderate or serious property damage.  
ELECTRONIC / ELECTRICAL / MECHANICAL  
Periodically (at least yearly or bi-yearly): inspect  
all control components: electronic, electrical and  
mechanical, as well as the power supply. Use proper  
testing instruments (voltmeter, ohmmeter, ammeter,  
wattmeter, etc.) to perform electrical tests. Use an air  
conditioning or refrigeration thermometer to check  
room, outdoor and coil operating temperatures.  
NOTICE  
Do not use a caustic coil cleaning agent on coils or base  
pan. Use a biodegradable cleaning agent and degreaser,  
to prevent damage to the coil and/or base pan.  
AIR FILTER  
BLOWER/FAN MOTOR  
The motor is permanently lubricated.  
The air lter should be inspected weekly and cleaned  
if needed by vacuuming with a dust attachment or  
by cleaning in the sink using warm water and a mild  
dishwashing detergent. Dry the lter thoroughly before  
reinstalling. Use caution as the coil surface can be sharp.  
TO REMOVE, WASH AND REPLACE FILTER  
Lower front panel. Use handle on lter to ex lter  
up and out of retainer. Remove lter from unit. Clean  
lter monthly or more frequently if needed. Refer to  
accessories section for lter options.  
50  
ROUTINE MAINTENANCE (Continued)  
NOTICE  
Do not drill holes in the bottom of the drain pan or the  
underside of the unit. Not following this notice could  
result in damage to the unit or condensate water leaking  
inappropriately which could cause water damage to  
surrounding property.  
SLEEVE / DRAIN  
Inspect the sleeve and drain system periodically (at least yearly or bi-yearly) and clean of all obstructions and  
debris. Clean both areas with an antibacterial and antifungal cleaner. Rinse both items thoroughly with water and  
ensure that the drain outlets are operating correctly. Check the sealant around the sleeve and reseal areas as  
needed.  
DECORATIVE FRONT COVER  
Clean the front cover when needed. Use a mild detergent. Wash and rinse with warm water. Allow it to dry  
thoroughly before reinstalling it in the chassis.  
The decorative front and the cabinet can be cleaned with warm water and a mild liquid detergent. Do NOT use  
solvents or hydrocarbon based cleaners such as acetone, naphtha, gasoline, benzene, etc.  
Use a damp (not wet) cloth when cleaning the control area to prevent water from entering the unit, and possibly  
damaging the electronic control.  
CLEARANCES  
Inspect the surrounding area (inside and outside) to ensure that the unit’s clearances have not been compromised or  
altered.  
Accumulator  
Outdoor Grille  
Discharge Air  
Compressor  
Fresh Air Vent  
Reversing Valve  
Evaporator Coil  
Condenser Coil  
Sleeve  
Air Intake Vents  
Electronic Control  
Board  
Control Key Pad  
Support Bar  
Blower Wheel  
Fan Blade  
Fan/Blower Motor  
Base Pan  
Air Intake From  
Sides and Bottom  
Control Key Pad  
(User Interface)  
Chassis Pull  
Out Handle  
51  
ROUTINE MAINTENANCE (Continued)  
Standard Filter Cleaning Installation Instructions  
STEP 2.  
3
STEP 1.  
NOTE:  
Figure 1  
Figure 3  
FILTER  
FILTER  
GRIP  
Remove the filter by grabbing it from its handle, lifting it up and swinging  
it out.  
STEP 3.  
Swing the front frame open. Clean the front frame by washing  
Figure 2  
Figure 4  
A
FILTER  
GRIP  
TOP TAB  
FRONT  
FRAME WITH  
STANDARD  
MESH FILTER  
HANDLE  
STEP 4.  
STEP 5.  
the inside of the front door.  
NOTE:  
the tab in the frame stops the handle from sliding in, slide the  
filter halfway up, tilt it towards the front of you, then gently slide  
it up fully. Do not force the handle into the frame.  
52  
ROUTINE MAINTENANCE (Continued)  
Heat pumps operate differently  
If your unit is a "Y", or heat pump model, there are some things that you  
will want to be aware of. Some functions of a heat pump differ from your  
unit when it is used for heating:  
After Maintenance/Repair  
Start-up Checklist and Notes  
Inspect and ensure that all components and accessories have been  
installed properly and that they have not been damaged during the  
installation progress.  
1. It is normal for ice to form on the outdoor coil of the heat pump.  
Moisture in the outside air, passing over the coil when very cold,  
will form ice.  
Check the condensate water drain(s) to ensure that they are adequate  
for the removal of condensate water, and that they meet the approval  
of the end user.  
2. If the outdoor temperature drops below 37° F (3° C), your heat  
pump will automatically turn on the electric resistance heat. When  
the temperature rises to 40° F (4° C), the compressor will resume  
the heat pump operation. If your unit is a 115 volt model (YS10),  
it is designed for use in warmer climates and does not have an  
electrical heat feature, and will not provide adequate heat below  
37° F (2.8° C).  
Ensure that all installation instructions concerning clearances around  
the unit have been adhered to. Check to ensure that the unit air lter,  
indoor coil, and outdoor coil are free from any obstructions.  
Ensure that the circuit breaker(s) or fuse(s) and supply circuit wire  
size have been sized correctly. If the unit was supplied with a power  
supply cord, insure that it is stored properly.  
CONTROL PANEL BATTERY CHANGE  
PROCEDURE  
Remove the grille, by loosening four (4) captive screws (See Figure 1).  
Remove one (1) screw on the battery retaining door (See Figure 2). Remove  
and replace the battery (CR2450). Reinstall the battery retaining door. Align  
the grille guide pins then tighten the four (4) captive screws. Before closing  
the grille panel door, check the lter. Clean or replace it as necessary.  
Ensure that the entire installation is in compliance with all applicable  
national and local codes and ordinances having jurisdiction.  
Secure components and accessories, such as a decorative front  
cover.  
Start the unit and check for proper operation of all components in  
each mode of operation.  
Instruct the owner or operator of the units operation, and the  
manufacturer's Routine Maintenance.  
Figure 1  
NOTE: A log for recording the dates of maintenance and/or service is  
recommended.  
Present the owner or operator of the equipment with the name,  
address and telephone number of the Authorized Friedrich Warranty  
Service Company in the area for future reference if necessary.  
NOTE: This is a warm weather appliance  
USE HAND TOOLS  
DO NOT OVER TIGHTEN  
The air conditioner is designed to cool in warm weather when the outside  
temperature is above 60° F (15.6° C) and below 115° F (46.1° C), so it won't  
cool a room if it is already cool outside. If you want to cool a room in the  
spring or fall, select the FAN ONLY mode and set the Fresh Air/Exhaust  
air control to Fresh Air. This will bring in a supply of cooler outside air.  
Condensation is normal  
Air conditioners actually pump the heat and humidity from your room to the  
outside. Humidity becomes water, and your air conditioner will use most of  
the water to keep the outside coil cool. If there is excessive humidity, there  
may be excess water that will drip outside. This is normal operation.  
1. USE HAND TOOLS WHEN INSTALLING AND  
REMOVING FRONT PANEL.  
DO NOT OVERTIGHTEN SCREWS.  
2. DISCONNECT POWER AND FOLLOW ALL  
LABELED WARNINGS WHEN FRONT PANEL  
IS REMOVED.  
Frosting  
This usually occurs because of insufcient airow across the coils, a dirty  
lter, cool damp weather, or all of these. Set the SYSTEM mode to FAN  
ONLY and the frost will disappear. Setting the thermostat a little warmer  
will probably prevent the frosting from recurring.  
Figure 2  
Noises  
All air conditioners make some noise. Friedrich units are designed to operate  
as quietly as possible. An air conditioner mounted in a wall is quieter than  
one mounted in a window. It is important to ensure that the chassis seal  
gasket is properly installed (refer to installation instructions).  
Battery type: Lithium, 3 Volts, #CR2450  
53  
Service and Assistance  
Before calling for service, please check the “Troubleshooting Tips” section  
on pages 40 and 41. This may help you to nd the answer to your problem,  
avoid unnecessary service calls, and save you the cost of a service call if  
the problem is not due to the product itself. If you have checked the “Basic  
Troubleshooting” section and still need help, it is available as follows:  
You can nd the name of your local Authorized Service Provider by visiting  
If you require further assistance  
You can call the Customer Support Call Center at 1-800-541-6645.  
Before calling, please make sure that you have the complete model and  
serial number, and date of purchase of your equipment available. By  
providing us with this information, we will be better able to assist you.  
Our specialists are able to assist you with:  
Specications and Features of our equipment.  
Referrals to dealers, and distributors.  
Use and Care Information.  
Recommended maintenance procedures.  
Installation information.  
Referrals to Authorized Service Providers and Parts depots.  
Available Accessories  
DC-2 Drain Kit – Part No. 01900235  
In some installations, excess condensate water caused by extremely humid  
conditions, may result in an undesirable water drip such as on a patio or  
over an entryway. MODEL DC-2 DRAIN KIT (Part No. 01900-235) can be  
installed to drain excess condensation to an alternate location.  
Carbon Filter Kits  
The kits vary depending on the chassis size (small, medium, large). Each  
kit contains three (3) lters.  
WCFS – Carbon lter kit for small chassis models.  
WCFM – Carbon lter kit for medium chassis models.  
WCFL – Carbon lter kit for large chassis models.  
Remote Wall Thermostats  
RT4 – Digital wall thermostat hard wired with single speed fan.  
RT5 – Digital wall thermostat hard wired with a digital display, two fan speed  
selection, lter check light, temperature limiting, status indicator light, room  
temperature offset, backlight and battery backup.  
Window Installation Kits (Standard in Kühl  
Models without Heat)  
KWIKS – For all ES and YS models.  
KWIKM – For all EM and YM models.  
KWIKL – For all EL and YL models.  
54  
ROOM AIR CONDITIONER UNIT PERFORMANCE TEST DATA SHEET  
JOB NAME________________________________ TECHS NAME____________________________________  
DATE: _______________ MODEL:_______________ SERIAL:________________  
HOW IS ALL OF THE INSTALLATION?  
GOOD BAD  
YES  
____  
____  
____  
____  
____  
NO  
____  
____  
____  
____  
____  
IS A C HAS S IS S E AL G AS K E T INT ALLE D ?  
IS THE FR E S H/E XAUS T AIR V E NT OP E N?  
IS A FR IE DR IC H S LE E VE INS TAL LE D?  
IS A FR IE DR IC H OUT DOOR G R IL LE INS T ALLE D?  
IS MAINTE NANC E B E ING PE R FOR ME D?  
If NO is checked use back of sheet for explanation  
E LE C T R IC AL:  
LINE VOLTAGE (STATIC)  
START UP VOLTAGE  
AMPERAGE DRAW  
AMPERAGE DRAW  
C OMP R E S S OR  
--------- VOLTS  
-------- VOLTS  
--------- AMPS (COOL)  
--------- AMPS (HEAT)  
LOCKED ROTOR AMPS  
AMPERAGE DRAW  
--------- AMPS  
--------- AMPS  
INDOOR TE MP E R AT UR E S :  
INDOOR AMBIENT TEMPERATURE  
RELATIVE HUMIDITY (RH) INDOOR  
-------- F  
-------- %  
C OOL  
---------- F --------- F  
---------- F --------- F  
HE AT  
DISCHARGE AIR TEMPERATURE (INDOOR)  
RETURN AIR TEMPERATURE (INDOOR)  
OUTDOOR T E MPE R AT UR E :  
OUTDOOR AMBIENT TEMPERATURE  
RH OUTDOOR  
--------- F  
--------- %  
DISCHARGE AIR TEMPERATURE (OUTDOOR)  
INTAKE AIR TEMPERATURE (OUTDOOR)  
--------- F ---------- F  
--------- F ---------- F  
APPLICATION USE ------------------------- ROOM (RESIDENTIAL OR COMMERCIAL)  
COOLING OR HEATING AREA W ---------- X L ----------- X H ----------- = SQ/CU/FT ------------  
T his is a general guide. pleas e c ons ult manual J or M.  
This is a general guide.  
Please consult manual J or M for exact load calculations.  
55  
ERROR CODES AND ALARM STATUS  
Maintenance  
ICON  
Error  
Code  
Problem  
Control Board's Action  
Continue to monitor for "OPEN" (Unstuck) switch. Do not process switch  
Front Panel Button Stuck For More  
Than 20 Seconds  
1
Flash  
ENSURE FRONT COVER DOES NOT DEPRESS BUTTONS  
input.  
Input Voltage Out of Specification (103  
- 127 / 187 - 253)  
Indoor Temperature Sensor is Open or Set temp to 75°F in COOLING or 68°F in HEATING. Unit continues to  
2
3
4
Flash  
Flash  
Flash  
Stop.Open all relays until voltage is back within specs. Resume operation  
Shorted  
operate  
Indoor Coil Temperature Sensor is  
Open or Shorted  
Control Board sets temp to 40°F. Override sensor. Unit Continues to  
operate.  
Sets temp to 20°F. Override sensor. Continue operation. Use Elec Heat if  
available for HEATING. If not available use HEAT PUMP if outdoor temp  
allows.  
Shut down for 5 min. Resume operation for 3 min. Continues to monitor. If  
test fails 3 times, the severity is increased and the unit operation is locked  
out.  
Outdoor Coil Temperature Sensor is  
Open or Shorted  
5
6
Flash  
Flash  
Outdoor Coil > (grater than) 175 F  
Indoor Coil < (less than) 30 F for 2  
consecutive minutes  
Unit Cycles > (grater than) 9 Times per  
hour  
Unit Cycles < (less than) 3 Times per  
Hour  
Turn compressor off. Run High Fan speed. When coil temp reachs 45°F  
resume operation after lockout time.  
7
8
9
Flash  
Log Only  
Log Only  
Continue operation. Continue to monitor. Take no action. Log Only.  
Continue operation. Continue to monitor. Take no action. Log Only.  
Only used if Electric Heat is available. Run High Speed and Electric heat  
until room temp reaches 46°F. Display "FRZ" during operation. Logged  
Only  
Severity 4 error is. Unit operates based on standard input mapping.  
Severity 2 error opens all relays. Unit will not operate.  
10  
11  
12  
Log Only  
On  
Room Freeze Protection  
WallStat Problem or Connection Issue  
Discharge Air > (greater than) 185 F  
Shutdown heat pump and electric heater. Run high fan speed until temp is  
100°F. Resume operation. Third occurance in 1 hour locks unit out.  
Flash  
If unit is cooling or heat pump on,shut down compressor. Run high fan until  
switch closes. Resume operation. Third occurance in 1 hour locks unit out.  
13  
Flash  
Prerssure Limit Switch Open  
Discharge Air Temperature Sensor is Override Sensor. Set temp to 75°F. Continue to monitor. Set error code 14  
14  
15  
16  
17  
Flash  
Solid On  
Flash  
Open or Shorted  
ON.  
If indoor coil temp < (Lesser than) ambient temp for 3 minutes. Unit uses  
electric heat to satisfy heating demand.  
Heat Pump Error  
Ambient temp < (less than) 0°F and ambient temp > (greater than) 130°F.  
Set error code 16 ON. When cleared return unit to normal.  
Temperature Beyond Operating Limits  
Equipment Doesn't Meet Minimum  
Configuration  
Flash  
Must have compressor enabled and at least 2 fan speeds  
Unit shuts down. Inputs via front panel or t-stat are ignored. Qualified  
Technical Service required URGENT  
Unit operates. Qualified Technical Service required  
Error is Logged Only. Unit operates. Severity 3 keeps unit running.  
Attention is needed  
18  
19  
20  
21  
22  
Flash  
Flash  
Special Test 1 Severity Level 1  
Special Test 2 Severity Level 2  
Special Test 3 Severity Level 3  
Solid On  
OFF, Log Only Special Test 4 Severity Level 4  
Error is Logged Only. Unit operates. Severity 4 keeps unit running.  
Outdoor Coil Temperature < 30 F for 2 Unit will use electric heat to satisfy heating demands until temp > 45°F.  
consecutive Minutes Unit must be a Heat Pump.  
OFF, Log Only  
OFF, Log Only  
Flash  
Frost Protection (for Heat Pump Only Unit will run active defrost for a minimum of 6 minutes when Heat Pump  
23  
24  
Unit- YS10M10)  
run time is greater than 60 minutes and outdoor coil temp is 26 F or less.  
Outdoor Air Temperature Sensor is  
Open or Shorted  
Continue with normal operation. Continue to monitor sensor.  
Key Sequence  
Action  
Enter Maintenance Menu  
Reset Error Codes & Error History Press  
Press SYSTEM + SCHEDULE + BACK + DISPLAY/ENTER for 6 secs or until double beep sounds()  
for 3 secs or until double beep sounds ()  
+
56  
TROUBLESHOOTING TIPS  
NOTE: To more accurately identify the problem, rst check for current maintenance  
alerts and their history.  
Problem  
Possible Cause  
Possible Solution  
Turn the unit to the on position and raise or  
lower temperature setting (as appropriate) to  
call for operation.  
The unit is turned to the off position,  
Plug into a properly grounded 3 prong  
receptacle. See “Electrical Rating Tables” on  
pg. 6 for the proper receptacle type for your  
unit.  
The LCDI power cord is unplugged.  
Press and release RESET (listen for click;  
Reset button latches and remains in) to resume  
operation.  
Unit does not operate.  
The LCDI power cord has tripped  
(Reset button has popped out).  
Reset the circuit breaker, or replace the fuse as  
applicable. If the problem continues, contact a  
licensed electrician.  
The circuit breaker has tripped or  
the supply circuit fuse has blown.  
There has been a local power  
failure.  
The unit will resume normal operation once  
power has been restored.  
Other appliances are being used on  
the same circuit.  
The unit requires a dedicated outlet circuit, not  
shared with other appliances.  
Do NOT use an extension cord with this or any  
other air conditioner.  
An extension cord is being used.  
Unit Trips Circuit Breaker or  
Blows Fuses.  
Replace with a circuit breaker or time-delay  
fuse of the proper rating. See “Electrical  
Rating Tables” on pg. 6 for the proper circuit  
breaker/fuse rating for your unit. If the problem  
continues, contact a licensed electrician.  
The circuit breaker or time-delay  
fuse is not of the proper rating.  
The LCDI power cord can trip  
(Reset button pops out) due to  
disturbances on your power supply  
line.  
Press and release RESET (listen for click;  
Reset button latches and remains in) to resume  
normal operation.  
LCDI Power Cord Trips (Reset  
Button Pops Out).  
Once the problem has been determined and  
corrected, press and release RESET (listen for  
click; Reset button latches and remains in) to  
resume normal operation.  
Electrical overload, overheating, or  
cord pinching can trip (Reset button  
pops out) the LCDI power cord.  
NOTE: A damaged power supply cord must be replaced with a new power supply cord  
obtained from the product manufacturer and must not be repaired.  
Ensure that the return and/or discharge air  
The return/discharge air grille is  
paths are not blocked by curtains, blinds,  
blocked.  
furniture, etc.  
Windows or doors to the outside are  
Ensure that all windows and doors are closed.  
open.  
The temperature is not set at a cool  
enough/warm enough setting.  
Adjust the Temperature control to a cooler or  
warmer setting as necessary.  
Unit Does Not Cool/Heat  
On And Off Too Frequently.  
remove obstruction.  
The indoor coil or outdoor coil is  
dirty or obstructed.  
Clean the coils, (See Routine Maintenance), or  
remove obstruction.  
Be sure to use exhaust vent fans while cooking  
or bathing and, if possible, try not to use heat  
producing appliances during the hottest part of  
the day.  
There is excessive heat or moisture  
(cooking, showers, etc.) in the room.  
The temperature of the room you  
are trying to cool is extremely hot.  
Allow additional time for the air conditioner to  
cool off a very hot room.  
57  
TROUBLESHOOTING TIPS (Continued)  
Problem  
Possible Cause  
Possible Solution  
Do not try to operate your air conditioner in the  
cooling mode when the outside temperature  
is below 60° F (16° C). The unit will not cool  
properly, and the unit may be damaged.  
The outside temperature is below  
60° F (16° C).  
Since the fan does not circulate the room  
air continuously at this setting, the room air  
does not mix as well and hot (or cold) spots  
may result. Using the continuous fan setting  
is recommended to obtain optimum comfort  
levels.  
The digital control is set to fan  
cycling mode.  
Unit Does Not Cool/Heat  
On And Off Too Frequently  
(continued).  
Check the cooling capacity of your unit to  
ensure it is properly sized for the room in which  
it is installed. Room air conditioners are not  
designed to cool multiple rooms.  
cooling capacity to match the heat  
gain of the room.  
Check the heating capacity of your unit. Air  
conditioners are sized to meet the cooling load,  
and heater size is then selected to meet the  
heating load. In extreme northern climates,  
room air conditioners may not be able to be  
used as a primary source of heat.  
heating capacity to match the heat  
loss of the room.  
If there are heat producing appliances in use  
in the room, or if the room is heavily occupied,  
the unit will need to run longer to remove the  
additional heat.  
This may be due to an excessive  
heat load in the room.  
Be sure to use exhaust vent fans while cooking  
or bathing and, if possible, try not to use heat  
producing appliances during the hottest part of  
the day.  
It may also be due to an improperly  
sized unit.  
your new air conditioner may result in the  
unit running longer than you feel it should.  
This may be more apparent, if it replaced an  
This may be normal for higher  
Unit Runs Too Much.  
compared to older models.  
You may notice that the discharge  
air temperature of your new air  
conditioner may not seem as cold  
as you may be accustomed to from  
older units. This does not, however,  
indicate a reduction in the cooling  
capacity of the unit.  
capacity rating (Btu/h) listed on the unit’s rating  
58  
COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS  
Possible Solution  
Problem  
Possible Cause  
Low voltage  
Check voltage at compressor. 115V & 230V  
units will operate at 10% voltage variance  
Temperature not set cold enough or Set temperature to lower than ambient position.  
room air thermistor inoperative  
Test thermistor and replace if inoperative.  
Compressor hums but cuts off on  
overload  
Hard start compressor. Direct test compressor.  
If compressor starts, add starting components  
Compressor  
does not run  
Open or shorted compressor  
windings  
Check for continuity & resistance  
Open overload  
Test overload protector & replace if inoperative  
Test capacitor & replace if inoperative  
Test for continuity in all positions. Replace if  
inoperative switch or electronic board.  
Refer to appropriate wiring diagrams to check  
wiring. Correct as needed.  
Open capacitor  
Inoperative system button  
Broken, loose or incorrect wiring  
Possible Solution  
Problem  
Possible Cause  
Inoperative system button  
Broken, loose or incorrect wiring  
Open capacitor  
Test button & replace user interface if inoperative  
Refer to applicable wiring diagram  
Fan motor  
Test capacitor & replace if inoperative  
Replace user interface if inoperative  
does not run  
Fan speed button defective  
Test fan motor & replace if inoperative (be sure  
internal overload has had time to reset)  
Inoperative fan motor  
Problem  
Possible Cause  
Possible Solution  
Undersized unit  
Refer to industry standard sizing chart  
Indoor ambient thermistor open  
or shorted  
See alarms and replace thermistor if needed.  
Dirty lter  
Clean as recommended in Owner’s Manual  
Use pressure wash or biodegradable cleaning  
agent to clean  
Dirty or restricted condenser or  
evaporator coil  
Does not cool or  
only cools slightly  
Poor air circulation  
Adjust discharge louvers. Use high fan speed  
Close doors. Instruct customer on use of this  
feature  
Fresh air or exhaust air door open  
Low capacity - undercharge  
Check for leak & make repair  
Check amperage draw against nameplate. If  
not conclusive, make pressure test  
Compressor not pumping properly  
59  
COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS  
Problem  
Possible Cause  
Possible Solution  
Replace fuse, reset breaker. If repeats, check  
fuse or breaker size. Check for shorts in unit  
wiring & components  
Fuse blown or circuit tripped  
Power cord not plugged in  
Plug it in  
System button in “OFF” position  
Set correctly  
Unit does not run  
Inoperative system button or open  
electronic control board  
Test for continuity. Check alarms. Correct  
as needed.  
Loose or disconnected wiring  
Check wiring & connections. Reconnect per  
wiring diagram  
control board or other components  
Problem  
Possible Cause  
Possible Solution  
Clean as recommended in Owner’s Manual  
Check for dirty or obstructed coil. Use  
pressure wash or biodegradable cleaning  
agent to clean  
Dirty lter  
Restricted airow  
Inoperative thermistor  
Short of refrigerant  
Check alarms. Replace as necessary.  
De-ice coil & check for leak  
Evaporator coil  
freezes up  
Inoperative fan motor  
Partially restricted capillary tube  
Test fan motor & replace if inoperative  
De-ice coil. Replace capillary tube.  
Possible Solution  
Problem  
Possible Cause  
Unit undersized. Test cooling performance &  
replace with larger unit if needed. See sizing chart.  
Check for partially iced coil & check  
temperature split across coil  
Excessive heat load  
Restriction in line  
Refrigerant leak  
Compressor runs  
continually & does  
not cycle off  
Find leak and repair.  
Check operation of t-stat. Replace if contacts  
remain closed.  
Compressor relay contacts stuck  
Remote wall T-stat incorrectly wired Refer to appropriate wiring diagram  
Thermistor shorted  
Replace thermistor or electronic control board  
Problem  
Possible Cause  
Possible Solution  
Compressor relay contacts stuck  
Temperature set at coldest point  
Incorrect wiring  
Replace electronic control board  
Turn to higher temp. setting to see if unit  
cycles off. If not, replace control board.  
Electronic control  
board does not  
turn unit off  
Refer to appropriate wiring diagrams  
Refer to industry standard sizing chart  
Replace thermistor or electronic control board  
Unit undersized for area to be  
cooled  
Defective thermistor  
60  
COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS  
Problem  
Possible Cause  
Overload inoperative. Opens too  
soon  
Possible Solution  
Check operation of unit. Replace overload if  
system operation is satisfactory  
Compressor restarted before  
system pressures equalized  
Control’s default of 3 minutes wait delay timer  
inoperative. Replace board.  
Check voltage with unit operating. Check for  
other appliances on circuit. Air conditioner  
should be in a dedicated circuit for proper  
voltage & fused separately  
Compressor runs  
for short periods  
only. Cycles on  
overload  
Low or uctuating voltage  
Incorrect wiring  
Refer to appropriate wiring diagram  
Shorted or incorrect capacitor  
Test capacitor and replace if needed.  
Restricted or low air flow through  
condenser coil or evaporator coil  
Check for proper fan speed or blocked  
coils. Correct as needed.  
Check for kinked discharge line or restricted  
Compressor running abnormally  
hot  
condenser. Refrigerant overcharge. Check  
amperage, connections.  
Problem  
Possible Cause  
Possible Solution  
Check power supply. Check LCDI plug. Check  
wire connections. Check if panel is locked.  
No power  
Unit does not  
turn on  
Incorrect wiring  
Refer to appropriate wiring diagram  
Defective thermistor  
Replace thermistor or electronic control board  
Problem  
Possible Cause  
Poorly installed  
Possible Solution  
Refer to Installation Manual for proper  
installation  
Fan blade striking chassis  
Reposition - adjust motor mount  
Check that compressor grommets have not  
deteriorated. Check that compressor mounting  
parts are not missing  
Noisy operation  
Compressor vibrating  
Improperly mounted or loose  
cabinet parts refrigerant tubes  
Check assembly & parts for looseness,  
rubbing & rattling pipes, etc.  
Problem  
Possible Cause  
Possible Solution  
Evaporator drain pan overowing  
Clean obstructed drain trough  
Evaporator drain pan broken or cracked.  
Reseal or replace. No chassis gasket installed.  
Install chassis gasket  
Condensation forming underneath  
base pan  
Poor installation resulting in rain  
entering the room  
Check installation instructions. Reseal as  
required  
Water leaks into  
the room  
Dirty evaporator coil. Use pressure wash  
or biodegradable cleaning agent to clean.  
Environmental phenomena: point supply  
louvers upward. Put on high fan.  
Condensation on discharge grille  
louvers  
Chassis gasket not installed  
Downward slope of unit is too  
steep inward  
Install gasket, per Installation manual  
Refer to installation manual for proper  
installation  
61  
COOLING ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS  
Problem  
Possible Cause  
Sublimation:  
Possible Solution  
Ensure that foam gaskets are installed in  
between window panes & in between the  
unit & the sleeve. Also, ensure that fresh  
air/exhaust vents (on applicable models) are in  
the closed position & are in tact  
When unconditioned saturated,  
outside air mixes with conditioned  
air, condensation forms on the  
cooler surfaces  
Water “spitting”  
into room  
Follow installation instructions to ensure that  
downward pitch of installed unit is no less than  
1/4” & no more than 3/8”  
Downward pitch of installation is  
too steep towards back of unit  
Clean & advise customer of periodic cleaning  
& maintenance needs of entire unit  
Restricted coil or dirty lter  
Problem  
Possible Cause  
Insufcient air circulation thru area  
to be air conditioned  
Possible Solution  
Adjust louvers for best possible air circulation  
Operate in “MoneySaver” position  
Advise customer  
Excessive  
moisture  
Oversized unit  
Inadequate vapor barrier in building  
structure, particularly oors  
Problem  
Possible Cause  
Defective thermistor  
Unit oversized  
Possible Solution  
Replace thermistor or electronic control board  
See sizing chart. Correct as needed.  
Unit  
Chassis seal gasket not sealing or  
absent causting unit to short cycle  
Check gasket. Reposition or replace as  
needed  
short cycles  
Clean & advise customer of periodic cleaning  
& maintenance needs of entire unit  
Restricted coil or dirty lter  
Problem  
Possible Cause  
Possible Solution  
Defective indoor ambient thermistor  
or electronic control board  
Check alarms. Replace thermistor or electronic  
control board  
Prolonged off  
cycles  
Defective remote wall t-stat  
Replace t-stat  
Problem  
Possible Cause  
Evaporator drain pan cracked or  
obstructed  
Possible Solution  
Repair, clean or replace as required  
Detach shroud from pan & coil. Clean &  
remove old sealer. Reseal, reinstall & check  
Use pressure wash or biodegradable cleaning  
agent to clean  
Water in compressor area  
Obstructed condenser coil  
Outside water  
leaks  
Fan blade/slinger ring improperly  
positioned  
Adjust fan blade to 1/2” of condenser coil n  
pack  
62  
HEAT / COOL ONLY ROOM AIR CONDITIONERS: TROUBLESHOOTING TIPS  
Problem  
Possible Cause  
Possible Solution  
Bad indoor ambient thermistor  
Check error codes. Replace as needed.  
Room temperature  
uneven  
(Heating cycle)  
Fan speed too low  
Set at higher fan speed.  
Close doors, windows, etc.  
Enable ATSF  
Opened door, windows, etc.  
ATSF (room air sampling feature) disabled  
Problem  
Possible Cause  
Possible Solution  
Bad outdoor coil thermistor  
Replace thermistor.  
Unit will not defrost  
• On heat pumps with electric heat: no action needed  
• On model YSM10: do not operate below 32°F/ 0°C  
(Heat pump  
only models)  
• If outdoor air temp is higher than freezing, check  
reversing valve, electric coil, outdoor thermistor,  
refrigerant circuits, etc.  
Temperature below 32°F/ 0°C  
• For proper operation: correct as needed  
Problem  
Possible Cause  
Exhaust or fresh air door open  
Dirty lter  
Possible Solution  
Check if operating properly. Instruct customer on  
proper use of control  
Clean as recommended in Owner's Manual  
Check heat rise across coil. If unit operates  
efciently, check if insulation can be added  
to attic or walls. If insulation is adequate,  
recommend additional unit or larger one  
Unit undersized  
Does not heat  
adequately  
Outdoor coil thermistor or electronic control  
board defective  
Check alarms (error codes). Replace thermistor  
or electronic control board.  
Check for adequate fan air across heater. Check  
for open hi-limit control.  
Heater hi-limit control cycling on & off  
Shorted or open supplementary heater  
Incorrect wiring  
Do ohmmeter check.  
Check applicable wiring diagram  
63  
HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS  
Problem  
Possible Cause  
Incorrect wiring  
Action  
Refer to applicable wiring diagram  
Check for continuity of coil  
Defective solenoid coil  
Reversing valve fails to shift  
Inoperative system switch  
Possible Cause  
Block condenser coil & switch unit to cooling.  
Allow pressure to build up in system, then  
switch to heating. If valve fails to shift, replace  
valve.  
Unit cools when  
heat is called for  
Check for continuity of system switch  
Problem  
Action  
Heating capillary tube partially  
restricted  
Check for partially starved outer coil. Replace  
heating capillary tube  
Switch unit several times from heating to  
cooling. Check temperature rise across  
coil. Refer to specication sheet for correct  
temperature rise  
Cooling adequate,  
but heating  
Check valve leaking internally  
insufcient  
Denergize solenoid coil, raise head pressure,  
energize solenoid to break loose. If valve fails  
to make complete shift, replace valve.  
Reversing valve failing to shift  
completely; bypassing hot gas  
TROUBLESHOOTING CHART - HEAT PUMP  
REFRIGERANT SYSTEM DIAGNOSIS - COOLING CYCLE  
LOW SUCTION PRESSURE  
HIGH SUCTION PRESSURE  
LOW HEAD PRESSURE  
HIGH HEAD PRESSURE  
Low Load Conditions  
High Load Conditions  
Low Load Conditions  
High Load Conditions  
Low Air Flow Across  
Indoor Coil  
High Air Flow Across  
Indoor Coil  
Refrigerant System  
Restriction  
Low Air Flow Across  
Outdoor Coil  
Refrigerant System  
Restriction  
Reversing Valve not  
Fully Seated  
Reversing Valve not  
Fully Seated  
Overcharged  
Undercharged  
Overcharged  
Undercharged  
in System  
Noncondensables (air)  
Moisture in System  
Defective Compressor  
Defective Compressor  
64  
HEAT PUMP ROOM AIR CONDITIONERS: TROUBLE SHOOTING TIPS  
REFRIGERANT SYSTEM DIAGNOSIS - HEATING CYCLE  
HIGH SUCTION PRESSURE  
HIGH HEAD PRESSURE  
LOW SUCTION PRESSURE  
LOW HEAD PRESSURE  
Low Airow  
Across Outdoor Coil  
Outdoor Ambient Too High  
for Operation in Heating  
Refrigerant System  
Restriction  
Outdoor Ambient Too High  
For Operation In Heating  
Refrigerant System  
Restriction  
Reversing Valve not  
Fully Seated  
Reversing Valve not  
Fully Seated  
Low Airow Across  
Indoor Coil  
Undercharged  
Overcharged  
Undercharged  
Overcharged  
Noncondensables (air)  
in System  
Moisture in System  
Defective Compressor  
Defective Compressor  
ELECTRICAL TROUBLESHOOTING CHART - HEAT PUMP  
HEAT PUMP  
SYSTEM COOLS WHEN  
HEATING IS DESIRED.  
Is the Selector Switch  
Set for Heat?  
Is Line Voltage  
Present at the Solenoid  
YES  
NO  
NO  
Is the Solenoid Coil Good?  
Replace the Solenoid Coil  
YES  
Reversing Valve Stuck  
Replace the Reversing Valve  
65  
TROUBLESHOOTING TOUCH TEST CHART: TO SERVICE REVERSING VALVES  
NORMAL FUNCTION OF VALVE  
NOTES:  
VALVE  
OPERATING  
CONDITION  
ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ  
* TEMPERATURE OF VALVE BODY  
** WARMER THAN VALVE BODY  
1
2
3
4
5
6
POSSIBLE CAUSES  
CORRECTIONS  
ꢀꢀ  
Cool  
as (2)  
Hot  
as (1)  
Hot  
Cool  
*TVB  
TVB  
Normal Cooling  
ꢀꢀ  
ꢀꢀ  
ꢀꢀ  
ꢀꢀ  
Hot  
as (1)  
Cool  
as (2)  
Hot  
Cool  
*TVB  
TVB  
Normal Heating  
MALFUNCTION OF VALVE  
No voltage to coil.  
Repair electrical circuit.  
Check Electrical circuit and coil  
Check refrigeration charge  
Defective coil.  
Replace coil.  
Low charge.  
Repair leak, recharge system.  
Recheck system.  
Pressure differential too high.  
Deenergize solenoid, raise head pressure,  
reenergize solenoid to break dirt loose.  
If unsuccessful, remove valve, wash  
out. Check on air before installing. If no  
movement, replace valve, add strainer to  
discharge tube, mount valve horizontally.  
Valve will not  
shift from cool  
to heat.  
Cool,  
as (2)  
Hot,  
as (1)  
Hot  
Cool  
*TVB  
Hot  
Pilot valve okay. Dirt in one bleeder hole.  
Stop unit. After pressures equalize, restart  
with solenoid energized. If valve shifts,  
reattempt with compressor running. If still  
no shift, replace valve.  
Piston cup leak  
ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ  
Cool,  
as (2)  
Hot,  
as (1)  
Raise head pressure, operate solenoid to  
free. If still no shift, replace valve.  
Hot  
Cool  
*TVB  
*TVB  
Clogged pilot tubes.  
Raise head pressure, operate solenoid  
to free  
partially clogged port. If still no shift,  
replace  
valve.  
Valve will not  
shift from cool  
to heat.  
Cool,  
as (2)  
Hot,  
as (1)  
Both ports of pilot open. (Back seat port  
did not close).  
Hot  
Cool  
Hot  
Hot  
Cool,  
as (2)  
Hot,  
as (1)  
Warm  
Hot  
Cool  
*TVB  
*TVB  
Warm  
Hot  
Defective Compressor.  
Replace compressor  
Not enough pressure differential at start  
of stroke or not enough ow to maintain and charge. Raise head pressure. If no  
Check unit for correct operating pressures  
Warm  
Warm  
Hot  
pressure differential.  
shift, use valve with smaller port.  
Body damage.  
Replace valve  
ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ  
Starts to shift  
but does not  
complete  
Raise head pressure, operate solenoid. If  
no shift, use valve with smaller ports.  
Hot  
Warm  
Warm  
Hot  
Hot  
Hot  
Both ports of pilot open.  
Body damage.  
Hot  
Hot  
Hot  
Hot  
*TVB  
Hot  
Replace valve  
Valve hung up at mid-stroke. Pumping  
volume of compressor not sufcient to  
maintain reversal.  
reversal.  
Raise head pressure, operate solenoid. If  
no shift, use valve with smaller ports.  
ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ  
Raise head pressure, operate solenoid.  
Hot  
Hot  
Hot  
Hot  
Hot  
Hot  
Both ports of pilot open.  
If no  
shift, replace valve.  
Hot,  
as (1)  
Cool,  
as (2)  
Operate valve several times, then recheck.  
If excessive leak, replace valve.  
Apparent  
leap in heat-  
ing.  
Hot  
Hot  
Hot  
Cool  
Cool  
Cool  
*TVB  
**WVB  
*TVB  
*TVB  
**WVB  
*TVB  
Piston needle on end of slide leaking.  
Pilot needle and piston needle leaking.  
Pressure differential too high.  
Clogged pilot tube.  
Hot,  
as (1)  
Cool,  
as (2)  
Operate valve several times, then recheck.  
If excessive leak, replace valve.  
Hot,  
as (1)  
Cool,  
as (2)  
Stop unit. Will reverse during equalization  
period. Recheck system  
Raise head pressure, operate solenoid to  
free dirt. If still no shift, replace valve.  
ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ ꢀꢀ  
ꢀꢀ  
Raise head pressure, operate solenoid.  
Remove valve and wash out. Check on air  
before reinstalling, if no movement, replace  
valve. Add strainer to discharge tube.  
Mount valve horizontally.  
Hot,  
as (1)  
Cool,  
as (2)  
Hot  
Cool  
Hot  
*TVB  
Dirt in bleeder hole.  
Piston cup leak.  
Will not shift  
from heat to  
cool.  
Stop unit. After pressures equalize, restart  
with solenoid deenergized. If valve shifts,  
reattempt with compressor running. If it  
still will not reverse while running, replace  
the valve.  
Hot,  
as (1)  
Cool,  
as (2)  
Hot  
Cool  
Hot  
*TVB  
1
Hot,  
as (1)  
Cool,  
as (2)  
Hot  
Cool  
Cool  
Hot  
Hot  
Defective pilot.  
Replace valve.  
Warm,  
as (1)  
Cool,  
as (2)  
Warm  
Warm  
*TVB  
Defective compressor.  
Replace compressor  
66  
ELECTRONIC CONTROL BOARD COMPONENTS IDENTIFICATION  
Front  
Back  
Reversing Valve  
Battery Compartment  
Max Speed  
High Speed  
Med Speed  
Low Speed  
DISCHARGE  
Transformer  
115/230 Volts  
User Interface  
connector  
T-stat Terminals  
Transformer voltage  
Selector Switch  
115/230 Volts  
Sample board for Kuhl+ unit  
67  
REMOTE WALL THERMOSTAT WIRING DIAGRAMS  
LEGEND FOR T-STAT WIRING HARNESS  
C
Common Terminal  
Call for High Fan  
Call for Low Fan  
Reversing Valve  
Coil for Cooling  
Call for Heat  
GH  
GL  
B
Y
W
R
24 VAC Power From Unit  
RT5 - Two Speeds Fan T-Stat - Field Provided  
-- -- -- Field Wiring  
COOL W/O ELECTRIC HEAT  
COOL WITH ELECTRIC HEAT  
Electronic Control Board  
24 VAC Connections  
Electronic Control Board  
24 VAC Connections  
Y
R
Y
R
W
GL  
W
C
GH GL  
B
C
GH  
B
Jumper  
Wire  
Jumper  
Wire  
GH GL  
O
B
Y
W
RC RH  
C
GH GL  
O
B
Y
W
RC RH  
C
RT5 Thermostat  
RT5 Thermostat  
HEAT PUMP ONLY AND  
HEAT PUMP WITH ELECTRIC HEAT  
Electronic Control Board  
24 VAC Connections  
Y
R
W
C
GH GL  
B
Jumper  
Wire  
GH GL  
O
B
Y
W
RC RH  
C
68  
KUHL  
ELECTRONIC CONTROL  
COOL ONLY MODELS  
SS08M10A, SS10M10A, SS12M10A, SS14M10A  
SS12M30A, SS15M30A  
SM18M30A, SM21M30A, SM24M30A  
WIRING DIAGRAM  
COMPRESSOR  
UI HOLDER ELECTRONICS ASY  
OLP  
OD AIR SENSOR  
OD COIL SENSOR  
ID COIL SENSOR  
F4  
BLACK  
BLUE  
RELAY  
F3  
RELAY  
ORANGE  
RED  
F2  
RELAY  
F1  
RELAY  
DCHRG  
AIR  
SENSOR  
TO  
DISPLAY  
L2 or ACN  
AMBIENT  
AIR SENSOR  
COMP  
RELAY  
BLACK  
L1  
BLACK  
WHITE  
WHITE  
SUPPLY CORD  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
MOTOR  
TO CHASSIS  
BLUE  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
(115 V)  
NEUTRAL  
USER I  
NTERFACE  
MAX  
L2 (230/208 V)  
4
F4  
L1  
R
HIGH  
3
F3  
F2  
OLP  
FAN MTR  
MEDIUM  
LOW  
FAN  
COM  
2
1
S
CAP  
F1  
L2 OR N  
COMP  
R
OLP  
COMPRESSOR  
C
COMPRESSOR  
5
L1  
HERM  
S
COM  
ELECTRONIC CONTROL  
CAP  
L E G E N D  
T
CAP  
- CAPACITOR  
- THERMISTER  
COMPR - COMPRESSOR  
- COMBINATION TERMINAL  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
- FAN MOTOR  
MTR  
OLP  
UI  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
TF  
HTR  
- HEATER ELEMENT  
HL  
- HEATER LIMIT FUSE  
PART NO.  
92170000  
REV.  
04  
69  
KUHL  
ELECTRONIC CONTROL  
COOL ONLY MODELS  
SL28M30A, SL36M30A  
COMPRESSOR  
OLP  
WIRING DIAGRAM  
UI HOLDER ELECTRONICS ASY  
OD AIR SENSOR  
OD COIL SENSOR  
ID COIL SENSOR  
F4  
RELAY  
F3  
RELAY  
BLACK  
BLUE  
RED  
F2  
RELAY  
F1  
RELAY  
DCHRG  
AIR  
SENSOR  
TO  
DISPLAY  
SOLID STATE RELAY  
WHITE  
L2 or ACN  
BLACK  
2
4
AMBIENT  
AIR SENSOR  
SSR  
BLUE  
1
3
COMP  
RELAY  
BLACK  
L1  
BLACK  
WHITE  
WHITE  
SUPPLY CORD  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
TO CHASSIS  
BLUE  
MOTOR  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
(115 V)  
NEUTRAL  
USER INT  
ERFAC  
E
L2  
(230/208 V)  
4
L1  
R
HIGH  
3
F3  
OLP  
FAN MTR  
MEDIUM  
LOW  
COM  
2
1
F2  
F1  
FAN  
S
CAP  
L2 OR N  
COMP  
R
OLP  
COMPRESSOR  
C
COMPRESSOR  
5
L1  
HERM  
S
COM  
ELECTRONIC CONTROL  
CAP  
L E G E N D  
T
CAP  
- CAPACITOR  
- THERMISTER  
COMPR - COMPRESSOR  
- COMBINATION TERMINAL  
MTR  
OLP  
UI  
- FAN MOTOR  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
TF  
HTR  
- HEATER ELEMENT  
HL  
- HEATER LIMIT FUSE  
PART NO.  
92170001  
REV.  
04  
70  
KUHL+  
ELECTRONIC CONTROL  
COOL WITH ELECTRIC HEAT MODELS  
ES12M33A, ES15M33A  
EM18M34A, EM24M34A  
WIRING DIAGRAM  
COMPRESSOR  
UI HOLDER ELECTRONICS ASY  
OLP  
OD AIR SENSOR  
OD COIL SENSOR  
RV  
RELAY  
ID COIL SENSOR  
FAN  
4
RELAY  
FAN 3  
RELAY  
BLACK  
BLUE  
FAN 2  
RELAY  
HEATER  
ORANGE  
RED  
ORANGE  
FAN 1  
RELAY  
HEAT  
RELAY  
DCHRG  
AIR  
TO  
DISPLAY  
SENSOR  
L2 or ACN  
HEAT  
RELAY  
BLACK  
AMBIENT  
AIR SENSOR  
COMP  
RELAY  
L1  
BLACK  
WHITE  
WHITE  
SUPPLY CORD  
RED  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
MOTOR  
TO CHASSIS  
BLUE  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
USER INT  
ERFAC  
E
HIGH  
L2  
(230/208 V)  
3
F3  
F2  
F1  
L1  
R
MEDIUM  
LOW  
2
OLP  
FAN MTR  
COM  
FAN  
1
S
ELECTRIC HEAT  
CAP  
HL  
TF  
6
7
HTR  
EH1  
EH2  
ELECTRIC HEAT  
L2 OR N  
COMP  
R
OLP  
COMPRESSOR  
C
COMPRESSOR  
5
L1  
COM  
HERM  
S
CAP  
ELECTRONIC CONTROL  
L E G E N D  
T
CAP  
- CAPACITOR  
- THERMISTER  
COMPR - COMPRESSOR  
- COMBINATION TERMINAL  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
MTR  
OLP  
UI  
- FAN MOTOR  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
TF  
HTR  
- HEATER ELEMENT  
HL  
- HEATER LIMIT FUSE  
PART NO.  
92170002  
REV.  
04  
71  
KUHL+  
ELECTRONIC CONTROL  
COOL WITH ELECTRIC HEAT MODEL  
EL36M35A  
WIR ING DIAG R AM  
UI HOLDE R E LE C TR ONIC S AS Y  
C OMP R E S S OR  
OLP  
O UTDO OR AIR  
S
E
NS OR  
R V  
R E LAY  
OUT DOOR C OIL S E NS OR  
INDOOR C OIL NS OR  
S
E
S OLID S TATE R E LAY  
S S R  
F AN  
R E LAY  
4
F AN  
R E LAY  
3
BLAC K  
BLUE  
R E D  
HE ATE R  
F AN  
R E LAY  
2
OR ANG E  
R E D  
F AN  
R E LAY  
1
HE AT  
R E LAY  
DS C HR G  
AIR  
S E NS OR  
T O  
DIS P LAY  
R E D  
L2 or AC N  
HE AT  
R E LAY  
S OLID S TATE R E LAY  
WHITE  
BLUE  
BLAC K  
AMB IE NT  
AIR S E NS OR  
C OMP  
R E LAY  
S S R  
B LUE  
B LAC K  
L1  
BLAC K  
WHIT E  
BLAC K  
WHIT E  
S UP P LY C OR D  
WHITE  
C AP AC ITOR  
C OM  
BR OWN  
R E D  
C AP AC ITOR  
BR AC KE T  
TO C AP AC ITOR  
BR AC KE T  
G R E E N  
MOTOR  
T O C HAS S IS  
BLUE  
TO INNE R WALL/  
MOT OR MOUNT  
S C HE MATIC  
(115 V)  
NE UTR AL  
US E R  
INTE R FAC E  
HIG H  
L2 (230/208 V)  
3
F3  
F 2  
F1  
L1  
R
ME DIUM  
LOW  
2
FAN MTR  
C OM  
C AP  
FAN  
1
S
E LE C T R IC HE AT  
HL  
TF  
6
HTR  
E H1  
E LE C T R IC HE AT  
L2  
R
C OMP R E S S OR  
OLP  
C OMP R E S S OR  
C
5
L1  
C OMP  
C OM  
HE R M  
S
C AP  
L E G E N D  
T
- THE R MIS TE R  
- C OMBINATION TE R MINAL  
C AP  
- C AP AC ITOR  
C OMP R - C OMP R E S S OR  
MTR  
OLP  
UI  
- F AN MOTOR  
- GR OUNDE D LE AD S Y MB OL  
- INS ULATOR  
- OVE R LOAD PR OTE C TOR  
- US E R INTE R FAC E  
- THE R MAL FUS E  
TF  
HTR  
- HE ATE R E LE ME NT  
HL  
- HE ATE R LIMIT F US E  
P AR T NO.  
92170007  
R E V.  
00  
72  
KUHL+  
ELECTRONIC CONTROL  
HEAT PUMP ONLY MODEL  
YS10M10A  
WIRING DIAGRAM  
COMPRESSOR  
OLP  
UI HOLDER ELECTRONICS ASY  
COIL, SOLENOID  
OD AIR SENSOR  
OD COIL SENSOR  
ID COIL SENSOR  
RV  
RELAY  
BLACK  
F4  
RELAY  
F3  
RELAY  
BLACK  
BLUE  
F2  
RELAY  
ORANGE  
F1  
RELAY  
DCHRG  
AIR  
SENSOR  
HEAT  
RELAY  
TO  
DISPLAY  
L2 or ACN  
HEAT  
RELAY  
BLACK  
AMBIENT  
AIR SENSOR  
COMP  
RELAY  
L1  
BLACK  
WHITE  
WHITE  
SUPPLY CORD  
RED  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
MOTOR  
TO CHASSIS  
BLUE  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
NEUTRAL (115 V)  
(230/208 V)  
USER I  
NTERFACE  
HIGH  
L2  
3
F3  
F2  
F1  
L1  
R
MEDIUM  
LOW  
2
OLP  
FAN MTR  
COM  
FAN  
1
S
CAP  
RV  
REVERSE CYCLE  
6
HP  
L2 OR N  
COMP  
R
OLP  
COMPRESSOR  
C
COMPRESSOR  
5
L1  
COM  
HERM  
S
ELECTRONIC CONTROL  
CAP  
L E G E N D  
- REVERSING VALVE  
- THERMISTER  
CAP  
- CAPACITOR  
- COMPRESSOR  
- FAN MOTOR  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
T
COMPR  
MTR  
OLP  
UI  
- COMBINATION TERMINAL  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
TF  
HL  
- HEATER LIMIT FUSE  
HTR  
- HEATER ELEMENT  
PART NO.  
92170003  
REV.  
04  
73  
KUHL+  
ELECTRONIC CONTROL  
HEAT PUMP WITH ELECTRIC HEAT MODELS  
YS12M33A, YM18M34A  
WIRING DIAGRAM  
COMPRESSOR  
UI HOLDER ELECTRONICS ASY  
COIL, SOLENOID  
OLP  
OD AIR SENSOR  
OD COIL SENSOR  
RV  
RELAY  
BLACK  
ID COIL SENSOR  
FAN  
4
RELAY  
FAN 3  
RELAY  
BLACK  
BLUE  
HEATER  
FAN  
RELAY  
2
ORANGE  
RED  
ORANGE  
FAN 1  
RELAY  
HEAT  
RELAY  
DCHRG  
AIR  
TO  
DISPLAY  
SENSOR  
L2 or ACN  
HEAT  
RELAY  
BLACK  
AMBIENT  
AIR SENSOR  
COMP  
RELAY  
L1  
BLACK  
WHITE  
WHITE  
SUPPLY CORD  
RED  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
MOTOR  
TO CHASSIS  
BLUE  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
NEUTRAL (115 V)  
(230/208 V)  
USER  
INTERFA  
CE  
L2  
HIGH  
3
F3  
F2  
F1  
L1  
R
MEDIUM  
LOW  
2
OLP  
FAN MTR  
S
COM  
FAN  
1
CAP  
ELECTRIC HEAT  
HL  
6
7
TF  
HTR  
EH1  
EH2  
ELECTRIC HEAT  
L2  
RV  
REVERSING CYCLE  
COMPRESSOR  
OLP  
R
8
5
RV  
C
COMPRESSOR  
L1  
COMP  
COM  
HERM  
S
ELECTRONIC CONTROL  
CAP  
L E G E N D  
- REVERSING VALVE  
- THERMISTER  
CAP  
- CAPACITOR  
T
COMPR - COMPRESSOR  
MTR  
OLP  
UI  
- FAN MOTOR  
- COMBINATION TERMINAL  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
TF  
HL  
- HEATER LIMIT FUSE  
HTR  
- HEATER ELEMENT  
PART NO.  
92170004  
REV.  
04  
74  
KUHL+  
ELECTRONIC CONTROL  
HEAT PUMP WITH ELECTRIC HEAT MODEL  
YL24M35A  
WIRING DIAGRAM  
COMPRESSOR  
UI HOLDER ELECTRONICS ASY  
OLP  
OUTDOOR AIR SENSOR  
RV  
RELAY  
OUTDOOR COIL SENSOR  
INDOOR COIL SENSOR  
SOLID STATE RELAY  
FAN 4  
RELAY  
4
2
SSR  
FAN 3  
RELAY  
BLACK  
BLUE  
RED  
1
3
HEATER  
FAN 2  
RELAY  
ORANGE  
FAN 1  
RED  
RELAY  
DSCHRG  
AIR  
SENSOR  
HEAT  
RELAY  
TO  
DISPLAY  
RED  
L2 or ACN  
HEAT  
RELAY  
SOLID STATE RELAY  
WHITE  
BLUE  
BLACK  
AMBIENT  
4
2
AIR SENSOR  
COMP  
RELAY  
SSR  
YELLOW  
BLACK  
1
3
L1  
BLACK  
WHITE  
BLACK  
WHITE  
SUPPLY CORD  
WHITE  
CAPACITOR  
COM  
BROWN  
RED  
CAPACITOR  
BRACKET  
TO CAPACITOR  
BRACKET  
GREEN  
MOTOR  
TO CHASSIS  
BLUE  
TO INNERWALL/  
MOTOR MOUNT  
SCHEMATIC  
(115 V)  
NEUTRAL  
USER  
INTERFA  
CE  
HIGH  
L2  
(230/208 V)  
3
F3  
F2  
F1  
L1  
R
MEDIUM  
LOW  
2
FAN MTR  
COM  
FAN  
1
S
CAP  
ELECTRIC HEAT  
HL  
TF  
6
HTR  
EH1  
ELECTRIC HEAT  
L2  
RV  
REVERSING CYCLE  
COMPRESSOR  
R
7
5
OLP  
RV  
C
COMPRESSOR  
L1  
COMP  
COM  
HERM  
ELECTRONIC CONTROL  
S
CAP  
SWITCH LOGIC X = CLOSED  
O = OPEN  
CIRCUIT  
L E G E N D  
SWITCH POSITION  
T
- THERMISTER  
CAP  
- CAPACITOR  
1
2
3
4
5
6
7
COMPR - COMPRESSOR  
O
O
O
X
O
0
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
X
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
X
X
X
X
X
X
O
O
O
O
O
O
O
O
O
O
O
O
O
X
O
O
O
O
X
OFF  
HI COOL  
- COMBINATION TERMINAL  
- GROUNDED LEAD SYMBOL  
- INSULATOR  
- FAN MOTOR  
MTR  
OLP  
UI  
- OVERLOAD PROTECTOR  
- USER INTERFACE  
- THERMAL FUSE  
MED COOL  
LOW COOL  
HI HEAT (HP)  
MED HEAT (HP)  
LOW HEAT (HP)  
HI HEAT (EH)  
MED HEAT (EH)  
LOW HEAT (EH)  
HI FAN  
TF  
HTR  
- HEATER ELEMENT  
X
HL  
- HEATER LIMIT FUSE  
X
O
O
O
O
O
O
X
X
O
O
O
MED FAN  
LOW FAN  
PART NO.  
92170008  
REV.  
00  
75  
THERMISTORS’ RESISTANCE VALUES  
(This Table Applies to All Thermistors)  
INDOOR AIR SENSOR  
RESISTENCE (K Ohms)  
CENTR  
RESISTANCE  
TEMP  
TOLERANCE %  
F
-25  
-20  
-15  
-10  
-5  
0
MIN  
MAX  
MIN  
MAX  
210.889  
178.952  
151.591  
128.434  
108.886  
92.411  
78.541  
66.866  
57.039  
48.763  
41.786  
35.896  
34.832  
33.803  
32.808  
31.846  
30.916  
30.016  
29.144  
28.319  
27.486  
26.697  
23.116  
20.071  
17.474  
15.253  
13.351  
13.004  
12.668  
12.341  
12.024  
11.716  
11.418  
11.128  
10.846  
10.574  
10.308  
10.051  
9.800  
225.548  
190.889  
161.325  
136.363  
115.340  
97.662  
82.812  
70.339  
59.864  
51.060  
43.654  
37.415  
36.290  
35.202  
34.150  
33.133  
32.151  
31.200  
30.281  
29.425  
28.532  
27.701  
23.931  
20.731  
18.008  
15.684  
13.697  
13.335  
12.984  
12.644  
12.313  
11.993  
11.682  
11.380  
11.088  
10.804  
10.528  
10.260  
10.000  
9.748  
240.224  
202.825  
171.059  
144.292  
121.794  
102.912  
87.083  
73.812  
62.688  
53.357  
45.523  
38.934  
37.747  
36.601  
35.492  
34.421  
33.386  
32.385  
31.418  
30.534  
29.579  
28.704  
24.745  
21.391  
18.542  
16.115  
14.043  
13.666  
13.301  
12.947  
12.603  
12.269  
11.946  
11.633  
11.329  
11.034  
10.748  
10.469  
10.200  
9.945  
6.50  
6.25  
6.03  
5.81  
5.60  
5.38  
5.16  
4.94  
4.72  
4.50  
4.28  
4.06  
4.02  
3.97  
3.93  
3.89  
3.84  
3.80  
3.75  
3.76  
3.67  
3.62  
3.40  
3.18  
2.96  
2.75  
2.53  
2.48  
2.44  
2.39  
2.35  
2.31  
2.26  
2.22  
2.18  
2.13  
2.09  
2.04  
2.00  
2.03  
2.07  
2.10  
2.13  
2.17  
2.20  
2.23  
2.27  
2.30  
2.33  
2.37  
2.40  
2.43  
2.47  
2.50  
2.53  
2.57  
2.60  
2.63  
2.67  
2.70  
2.73  
2.77  
2.93  
3.10  
3.27  
3.43  
6.51  
6.25  
6.03  
5.81  
5.60  
5.38  
5.16  
4.94  
4.72  
4.50  
4.28  
4.06  
4.02  
3.97  
3.93  
3.89  
3.84  
3.80  
3.75  
3.77  
3.67  
3.62  
3.40  
3.18  
2.96  
2.75  
2.53  
2.48  
2.44  
2.39  
2.35  
2.31  
2.26  
2.22  
2.18  
2.13  
2.09  
2.04  
2.00  
2.03  
2.07  
2.10  
2.13  
2.17  
2.20  
2.23  
2.27  
2.30  
2.33  
2.37  
2.40  
2.43  
2.47  
2.50  
2.53  
2.57  
2.60  
2.63  
2.67  
2.70  
2.73  
2.77  
2.93  
3.10  
3.27  
3.43  
5
10  
15  
20  
25  
30  
31  
32  
33  
34  
35  
36  
37  
38  
39  
40  
45  
50  
55  
60  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
75  
76  
77  
78  
79  
80  
81  
82  
83  
84  
85  
86  
87  
88  
89  
90  
91  
92  
93  
94  
95  
96  
97  
98  
99  
100  
105  
110  
115  
120  
9.550  
9.306  
9.503  
9.699  
9.070  
9.265  
9.459  
8.841  
9.033  
9.226  
8.618  
8.809  
9.000  
8.402  
8.591  
8.780  
8.192  
8.379  
8.566  
7.987  
8.172  
8.358  
7.789  
7.972  
8.155  
7.596  
7.778  
7.959  
7.409  
7.589  
7.768  
7.227  
7.405  
7.583  
7.050  
7.226  
7.402  
6.878  
7.052  
7.226  
6.711  
6.883  
7.055  
6.548  
6.718  
6.889  
6.390  
6.558  
6.727  
6.237  
6.403  
6.569  
6.087  
6.252  
6.417  
5.942  
6.105  
6.268  
5.800  
5.961  
6.122  
5.663  
5.822  
5.981  
5.529  
5.686  
5.844  
4.912  
5.060  
5.208  
4.371  
4.511  
4.651  
3.898  
4.030  
4.161  
3.482  
3.606  
3.730  
76  
Kühl Remote Control  
Replacement Remote Control Configuration Instructions  
For Use with Kühl (cool only models) and Kühl + (cool & heat models)  
Contents:  
Remote Control with Holder  
(2) AAA-batteries  
Instruction Sheet  
ATTENTION! – You May Need to Configure The Replacement Remote Control  
Please read instructions completely before attempting configuration of the Remote Control. Failure to  
do so could result in the Remote Control not being able to operate the Air Conditioning Unit properly.  
Step 1. A. Locate the Model # of your Air Conditioner.  
B. Identify the prefix (First 2 Letters) of your unit’s model #.  
C. Look at the chart below and in it, find the prefix of your AC unit’s model #.  
D. Note the Option # Code (OPT#) next to it and the required action. The unit’s  
display is supposed to show this OPT# Code.  
Model Prefix  
Option Code  
OPT 1  
OPT 2  
Required Action  
SS, SM  
SL  
None – Remote Control configured for use with air conditioner  
Perform Steps 2 - 5  
YS, YM, YL, ES, EM, EL  
OPT 3  
Perform Steps 2 - 5  
Step 2. Point the Remote Control at Air Conditioning Unit and then press the Remote Control’s  
POWER Key once to illuminate the Air Conditioning Unit’s display.  
Step 3. Once the display on the Air Conditioning Unit is illuminated, check the Option Code  
number (OPT#) shown in the display and ensure it matches the OPT# code for your unit  
as per the chart above.  
Air Conditioner Unit’s Display (see example below Fig 1)  
OPT1  
OPT2  
OPT3 Displayed example  
Figure 1  
77  
Kühl Remote Control  
Step 4  
Checking the Remote Control’s OPT # Code  
With the Remote Control’s display illuminated, press and hold the Remote Control’s  
SCHEDULE and the FAN SPEED Keys simultaneously for approximately 6 seconds until  
the Remote Control displays its current OPT# Code.  
If the OPT# Code is different than the AC Unit’s OPT# Code see instructions below:  
Remote Control  
Remote Control’s OPT# Code (see example below Fig 2)  
Figure 2  
Using the Remote Control’s S Increase or d Decrease Keys, change the OPT# Code  
displayed on the Remote Control to match the OPT # Code shown on the Air  
Conditioning Unit’s display (see examples below).  
Air Conditioning Unit Display  
Remote Control Display  
Step 5. To save the setting in the Remote Control, press and hold the Remote Control SCHEDULE  
and FAN SPEED Key simultaneously for approximately 6 seconds until the displayed  
configuration number on the Remote Control flashes.  
The Remote Control is now configured to work with the air conditioner.  
78  
Kühl User Interface Service Kit  
Replacement Instructions  
For Use with Kühl (cool only models) and Kühl + (cool and heat models)  
ATTENTION! - Please read these instructions completely before attempting replacement.  
Always unplug the power supply from the power supply receptacle.  
Contents:  
User Interface (UI)  
Ribbon Cable  
2 – Mounting screws for UI  
Instruction Sheet  
Step 1. Disconnect ribbon cable by pulling straight out  
Step 2. Remove 2 –mounting screws securing UI and disconnect ribbon cable  
Step 3. Remove UI and ribbon cable from handle assembly  
Step 4. Install new UI using the 2-screws, route new ribbon cable and reattach ribbon cable to UI  
and Main control board  
Step 5. Verify control operation  
Ribbon cable connection  
Mounting screws  
79  
INSTRUCTIONS FOR USING COOLING LOAD ESTIMATE  
FORM FOR ROOM AIR CONDITIONERS  
(AHAM PUB. NO. RAC-1)  
A. This cooling load estimate form is suitable for estimating the cooling load for comfort air conditioning installations  
which do not require specific conditions of inside temperature and humidity.  
B. The form is based on an outside design temperature of 95°F dry bulb and 75°F wet bulb. It can be used for areas  
in the continental United States having other outside design temperatures by applying a correction factor for the  
particular locality as determined from the map.  
C. The form includes “day” factors for calculating cooling loads in rooms where daytime comfort is desired (such as  
living rooms, offices, etc.)  
D. The numbers of the following paragraphs refer to the corresponding numbered item on the form:  
1. Multiply the square feet of window area for each exposure by the applicable factor. The window area is the  
area of the wall opening in which the window is installed. For windows shaded by inside shades or venetian  
blinds, use the factor for “Inside Shades.” For windows shaded by outside awnings or by both outside aw-  
nings and inside shades (or venetian blinds), use the factor for “Outside Awnings.” “Single Glass” includes  
all types of single thickness windows, and “Double Glass” includes sealed airspace types, storm windows,  
and glass block. Only one number should be entered in the right hand column for Item 1, and this number  
should represent only the exposure with the largest load.  
2. Multiply the total square feet of all windows in the room by the applicable factor.  
3a. Multiply the total length (linear feet) of all walls exposed to the outside by the applicable factor. Doors should  
be considered as being part of the wall. Outside walls facing due north should be calculated separately from  
outside walls facing other directions. Walls which are permanently shaded by adjacent structures should be  
considered “North Exposure.” Do not consider trees and shrubbery as providing permanent shading. An  
uninsulated frame wall or a masonry wall 8 inches or less in thickness is considered “Light Construction.” An  
insulated wall or masonry wall over 8 inches in thickness is considered “Heavy Construction.”  
3b. Multiply the total length (linear feet) of all inside walls between the space to be conditioned and any uncondi-  
tioned spaces by the given factor. Do not include inside walls which separate other air conditioned rooms.  
4. Multiply the total square feet of roof or ceiling area by the factor given for the type of construction most nearly  
describing the particular application (use one line only.)  
5. Multiply the total square feet of floor area by the factor given. Disregard this item if the floor is directly on the  
ground or over a basement.  
6. Multiply the number of people who normally occupy the space to be air conditioned by the factor given. Use  
a minimum of 2 people.  
7. Determine the total number of watts for light and electrical equipment, except the air conditioner itself, that  
will be in use when the room air conditioning is operating. Multiply the total wattage by the factor given.  
8. Multiply the total width (linear feet) of any doors or arches which are continually open to an unconditioned  
space by the applicable factor.  
NOTE: Where the width of the doors or arches is more than 5 feet, the actual load may exceed the calculated  
value. In such cases, both adjoining rooms should be considered as a single large room, and the room air  
conditioner unit or units should be selected according to a calculation made on this new basis.  
9. Total the loads estimated for the foregoing 8 items.  
10. Multiply the subtotal obtained in item 9 by the proper correction factor, selected from the map, for the particular  
locality. The result is the total estimated design cooling load in BTU per hour.  
E. For best results, a room air conditioner unit or units having a cooling capacity rating (determined in accordance  
with the NEMAStandards Publication for RoomAir Conditioners, CN 1-1960) as close as possible to the estimated  
load should be selected. In general, a greatly oversized unit which would operate intermittently will be much less  
satisfactory than one which is slightly undersized and which would operate more nearly continuously.  
F. Intermittent loads such as kitchen and laundry equipment are not included in this form.  
80  
COOLING LOAD ESTIMATE FORM  
FACTORS  
BTU/Hr.  
(Quantity x Factor)  
HEAT GAIN FROM  
QUANTITY  
DAY  
No  
Shades*  
60  
Outside  
(Area  
Inside  
1.  
WINDOWS: Heat gain from the sun.  
Awnings* X Factor)  
Shades*  
Northeast  
East  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
20 ____  
25 ____  
20 ____  
20 ____  
30 ____  
45 ____  
35 ____  
0 ____  
Use  
only  
the  
largest ____  
load. ____  
Use  
only  
one.  
____  
____  
____  
25  
40  
30  
35  
45  
65  
50  
0
* These factors are for single glass  
only. For glass block, multiply the  
above factors by 0.5; for double  
glass or storm windows, multiply the  
above factors by 0.8.  
80  
Southeast  
South  
Southwest  
West  
75  
75  
110  
150  
120  
0
____  
____  
____  
Northwest  
North  
2.  
3.  
WINDOWS: Heat by conduction  
(Total of all windows.)  
_____  
_____  
Single glass  
14  
7
____sq. ft.  
____sq. ft.  
Double glass or glass block  
WALLS: (Based on linear feet of wall)  
a. Outside walls  
Light Construction  
Heavy Construction  
_____  
_____  
North Exposure  
30  
60  
____ ft.  
____ ft.  
20  
30  
Other than North exposure  
b. Inside Walls (between conditioned and  
unconditioned spaces only.)  
_____  
30  
____sq. ft.  
4.  
5.  
ROOF OR CEILING: (Use one only)  
a. Roof, uninsulated  
b. Roof, 1 inch or more insulation  
c. Ceiling, occupied space above  
d. Ceiling, insulated, with attic space above  
e. Ceiling, uninsulated, with attic space above  
_____  
_____  
_____  
_____  
_____  
19  
8
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
____sq. ft.  
3
5
12  
_____  
Floor: (Disregard if floor is directly on ground or  
over a basement.  
3
____sq. ft.  
_____  
_____  
6.  
7.  
8.  
NUMBER OF PEOPLE  
600  
3
____  
LIGHTS AND ELECTRICAL EQUIPMENT IN USE  
____watts  
DOORS AND ARCHES CONTINUOUSLY  
OPENED TO UNCONDITIONED SPACE: (TOTAL  
LINEAR FEET OF WIDTH.)  
_____  
_____  
300  
____ft.  
*****  
9.  
SUBTOTAL  
*****  
10. TOTAL COOLING LOAD (BTU per hour to be used  
for selection of room air conditioner(s).)  
____ Total in Item 9 X ____ (Factor from Map) =  
____  
81  
HEAT LOAD FORM  
The heat load form on the following page may be used by  
Following is an example using the heat load form:  
servicingpersonneltodeterminetheheatlossofaconditioned  
space and the ambient winter design temperatures in which  
the unit will heat the calculated space.  
A space to be conditioned is part of a house geographically  
located in an area where the lowest outdoor ambient winter  
temperature is 40°F. The calculated heat loss is 184 BTU/  
Hr./°F.  
The upper half of the form is for computing the heat loss of  
the space to be conditioned. It is necessary only to insert  
the proper measurements on the lines provided and multiply  
by the given factors, then add this result for the total heat  
loss in BTU/Hr./°F.  
Subtract 40°F (lowest outdoor ambient temperature for the  
geographical location) from 70°F (inside design temperature  
of the unit) for a difference of 30°F. Multiply 184 by 30 for a  
5500 BTU/Hr. total heat loss for the calculated space.  
The BTU/Hr. per °F temperature difference is the 70°F  
inside winter designed temperature minus the lowest outdoor  
ambient winter temperature of the area where the unit is  
installed. This temperature difference is used as the multiplier  
when calculating the heat loss.  
On the graph, plot the base point (70°) and a point on the  
40°F line where it intersects with the 5500 BTU/Hr. line on  
the left scale. Draw a straight line from the base point 70  
through the point plotted at 40°F. This is the total heat loss  
line.  
The graph shows the following:  
Knowing that we have a 5500 BTU/Hr. heat loss, and  
we expect that our heat pump will maintain a 70°F inside  
temperature at 40°F outdoor ambient, we plot the selected  
unit capacity BTU/Hr. of the unit between 35° and 60° on the  
graph and draw a straight line between these points. Where  
the total heat loss line and the unit capacity line intersect,  
read down to the outdoor ambient temperature scale and  
find that this unit will deliver the required BTU/Hr. capacity  
to approximately 30°F.  
Left Hand Scale  
Unit capacity BTU/Hr. or heat loss  
BTU/Hr.  
Bottom Scale  
Outdoor ambient temperature, base  
point.  
Heat Pump Model  
Balance Point  
BTU/Hr. capacity heat pump will  
deliver at outdoor temperatures.  
Maximum BTU/Hr. heat pump  
will deliver at indicated ambient  
temperature.  
82  
HEATING LOAD FORM  
FRIEDRICH ROOM UNIT HEAT PUMPS  
BTU/HR PER  
WALLS: (Linear Feet)  
2” Insulation  
°F TEMP. DIFFERENCE  
Lin. Ft. x 1.6  
Average  
Lin. Ft. x 2.6  
WINDOWS & DOORS (Area, sq. ft.)  
Single Glass:  
Sq. Ft. x 1.13  
Sq. Ft. x 0.61  
Double Glass:  
INFILTRATION - WINDOWS & DOORS: AVG.  
Lin. Ft. x 1.0  
Lin. Ft. x 2.0  
Loose  
CEILING: (Area, Sq. Ft.)  
Insulated (6”)  
Sq. Ft. x 0.07  
Sq. Ft. x 0.10  
Sq. Ft. x 0.10  
Sq. Ft. x 0.20  
Sq. Ft. x 0.33  
Insulated (2”)  
Built-up Roof (2” insulated  
Built-up Roof (1/2” insulated)  
No Insulation  
FLOOR: (Area, Sq. Ft.)  
Above Vented Crawl space  
Insulated (1:)  
Sq. Ft. x 0.20  
Sq. Ft. x 0.50  
Uninsulated  
* Slab on Ground  
1” Perimeter insulation  
* Based on Linear Feet of outside wall  
Lin. Ft. x 1.70  
Lin. Ft. x 1.00  
TOTAL HEAT LOSS PER °F BTU/HR/°F  
Multiply total BTU/HR/°F X 30 and plot on the graph below at 40°F. Draw a straight line from  
the 70 base point thru the point plotted at 40°F. The intersection of this heat loss line with the  
unit capacity line represents the winter design heating load.  
83  
Friedrich Air Conditioning Company  
P.O. Box 1540  
San Antonio, TX 78295  
210.357.4400  
ROOM AIR CONDITIONERS  
LIMITED WARRANTY  
FIRST YEAR  
ANY PART: If any part supplied by FRIEDRICH fails because of a defect in workmanship or material within twelve months from date of original  
purchase, FRIEDRICH will repair the product at no charge, provided room air conditioner is reasonably accessible for service. Any additional  
labor cost for removing inaccessible units and/or charges for mileage related to travel by a Service Agency that exceeds 25 miles one way will  
be the responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy within twelve months from the date of the original  
purchase.  
SECOND THROUGH FIFTH YEAR  
SEALED REFRIGERANT SYSTEM: If the Sealed Refrigeration System (dened for this purpose as the compressor, condenser coil, evaporator  
coil, reversing valve, check valve, capillary, lter drier, and all interconnecting tubing) supplied by FRIEDRICH in your Room Air Conditioner fails  
because of a defect in workmanship or material within sixty months from date of purchase, FRIEDRICH will pay a labor allowance and parts  
necessary to repair the Sealed Refrigeration System; PROVIDED FRIEDRICH will not pay the cost of diagnosis of the problem, removal, freight  
charges, and transportation of the air conditioner to and from the Service Agency, and the reinstallation charges associated with repair of the  
Sealed Refrigeration System. All such cost will be the sole responsibility of the owner. This remedy is expressly agreed to be the exclusive remedy  
within sixty months from the date of the original purchase.  
APPLICABILITY AND LIMITATIONS: This warranty is applicable only to units retained within the Fifty States of the U.S.A., District of Columbia,  
and Canada. This warranty is not applicable to:  
1. Air lters or fuses.  
2. Products on which the model and serial numbers have been removed.  
3. Products which have defects or damage which results from improper installation, wiring, electrical current characteristics, or  
maintenance; or caused by accident, misuse or abuse, re, ood, alterations and/or misapplication of the product and/or units  
installed in a corrosive atmosphere, default or delay in performance caused by war, government restrictions or restraints, strikes,  
material shortages beyond the control of FRIEDRICH, or acts of God.  
OBTAINING WARRANTY PERFORMANCE: Service will be provided by the FRIEDRICH Authorized Dealer or Service Organization in your  
area. They are listed in the Yellow Pages. If assistance is required in obtaining warranty performance, write to: Room Air Conditioner Service  
Manager, Friedrich Air Conditioning Co., P.O. Box 1540, San Antonio, TX 78295-1540.  
LIMITATIONS: THIS WARRANTY IS GIVEN IN LIEU OF ALL OTHER WARRANTIES. Anything in the warranty notwithstanding, ANY  
IMPLIED WARRANTIES OF FITNESS FOR PARTICULAR PURPOSE AND/OR MERCHANTABILITY SHALL BE LIMITED TO THE DURATION  
OF THIS EXPRESS WARRANTY. MANUFACTURER EXPRESSLY DISCLAIMS AND EXCLUDES ANY LIABILITY FOR CONSEQUENTIAL  
OR INCIDENTAL DAMAGE FOR BREACH OF ANY EXPRESSED OR IMPLIED WARRANTY.  
Performance of Friedrich’s Warranty obligation is limited to one of the following methods:  
1. Repair of the unit  
2. A refund to the customer for the prorated value of the unit based upon the remaining warranty period of the unit.  
3. Providing a replacement unit of equal value  
The method of fulllment of the warranty obligation is at the sole discretion of Friedrich Air Conditioning.  
NOTE: Some states do not allow limitations on how long an implied warranty lasts, or do not allow the limitation or exclusion of consequential or  
incidental damages, so the foregoing exclusions and limitations may not apply to you.  
OTHER: This warranty gives you specic legal rights, and you may also have other rights which vary from state to state.  
PROOF OF PURCHASE: Owner must provide proof of purchase in order to receive any warranty related services.  
All service calls for explaining the operation of this product will be the sole responsibility of the consumer.  
All warranty service must be provided by an Authorized FRIEDRICH Service Agency, unless authorized by FRIEDRICH prior to repairs being  
made.  
(10-08)  
84  
TECHNICAL SUPPORT  
CONTACT INFORMATION  
FRIEDRICH AIR CONDITIONING CO.  
Post Ofce Box 1540 · San Antonio, Texas 78295-1540  
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212  
(210) 357-4400 · 877-599-5665 x 846 · FAX (210) 357-4490  
Printed in the U.S.A.  
FRIEDRICH AIR CONDITIONING CO.  
Post Ofce Box 1540 · San Antonio, Texas 78295-1540  
4200 N. Pan Am Expressway · San Antonio, Texas 78218-5212  
(210) 357-4400 · FAX (210) 357-4490  
Kuhl-ServMan (5-10)  
Printed in the U.S.A.  

BT paperjet 50 User Manual
Epson WorkForce 600 User Manual
Friedrich Air Conditioner CP05 User Manual
Frigidaire FSC12CH7M User Manual
General Electric Air Conditioner AGE21 User Manual
Haier HSU 12LEK03 User Manual
Haier HSU 229M07 User Manual
Hisense Group KFR 33GWE User Manual
HP Hewlett Packard HP PHOTOSMART PREMIUM C309 User Manual
HP Hewlett Packard K510 User Manual