Carrier 38AUZ User Manual

38AUZ  
Air-Cooled Condensing Units  
60 Hz  
with Puron® (R-410A) Refrigerant  
Sizes 07, 08, 12, 14  
Installation, Start-Up and  
Service Instructions  
CONTENTS  
SAFETY CONSIDERATIONS  
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . 1  
INSTALLATION GUIDELINES. . . . . . . . . . . . . . . . . . . . . . . 2  
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-13  
Step 1 — Plan for Unit Location . . . . . . . . . . . . . . . . . . 7  
Step 2 — Complete Pre-Installation Checks. . . . . . . . . 7  
Step 3 — Prepare Unit Mounting Support . . . . . . . . . 7  
Step 4 — Rig and Mount the Unit . . . . . . . . . . . . . . . . . 7  
Step 5 — Complete Refrigerant Piping Connections . 7  
Step 6 — Install Accessories . . . . . . . . . . . . . . . . . . . . . 9  
Step 7 – Complete Electrical Connections . . . . . . . . . . 9  
PRE-START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
Turn On Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . 14  
Preliminary Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
START-UP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 -18  
38AUZ Units. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14  
OPERATING SEQUENCE. . . . . . . . . . . . . . . . . . . . . . . . . . 18  
Cooling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
Heating. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18  
ROUTINE SYSTEM MAINTENANCE. . . . . . . . . . . . . . . 18  
Quarterly Inspection (and 30 days after initial start). 18  
Seasonal Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 18  
SERVICE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 - 23  
Comfort Alert Diagnostic Module. . . . . . . . . . . 19 - 21  
Crankcase Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Compressor Protection. . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Low-Pressure Switches . . . . . . . . . . . . . . . . . . . . . . . . . 21  
High-Pressure Switches. . . . . . . . . . . . . . . . . . . . . . . . . 21  
Outdoor Fans. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21  
NOVATION™ Coil Cleaning and Maintenance . . . . 22  
Repairing NOVATION Condenser Tube Leaks. . . . . 22  
Replacing NOVATION Condenser Coil . . . . . . . . . . 22  
Field Refrigerant Access Ports . . . . . . . . . . . . . . . . . 22  
Factory High-Flow Access Ports. . . . . . . . . . . . . . . . 22  
Fastener Torque Values . . . . . . . . . . . . . . . . . . . . . . . 23  
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 23, 24  
APPENDIX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25  
Improper installation, adjustment, alteration, service,  
maintenance, or use can cause explosion, fire, electrical shock  
or other conditions which may cause personal injury or  
property damage. Consult a qualified installer, service agency,  
or your distributor or branch for information or assistance. The  
qualified installer or agency must use factory-authorized kits or  
accessories when modifying this product. Refer to the  
individual instructions package  
Follow all safety codes. Wear safety glasses and work gloves.  
Use quenching cloths for brazing operations and have a fire  
extinguisher available. Read these instructions thoroughly and  
follow all warnings or cautions attached to the unit. Consult  
local building codes and appropriate national electrical codes  
(in USA, ANSI/NFPA70, National Electrical Code (NEC); in  
Canada, CSA C22.1) for special requirements.  
It is important to recognize safety information. This is the  
safety-alert symbol  
. When you see this symbol on the unit  
and in instructions or manuals, be alert to the potential for  
personal injury.  
Understand the signal words DANGER, WARNING,  
CAUTION, and NOTE. These words are used with the safety-  
alert symbol. DANGER identifies the most serious hazards  
which will result in severe personal injury or death.  
WARNING signifies hazards which could result in personal  
injury or death. CAUTION is used to identify unsafe practices,  
which may result in minor personal injury or product and  
property damage. NOTE is used to highlight suggestions  
which will result in enhanced installation, reliability, or  
operation.  
Air Conditioner and Heat Pump with Puron® —  
Quick Reference Guide . . . . . . . . . . . . . . . . . . . . . . . 25  
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . CL-1, CL-2  
Standard  
Weight  
Corner  
A
Corner  
B
Corner  
C
Corner  
D
Center of Gravity  
Unit Height  
UNIT  
lbs.  
kg.  
lbs.  
kg.  
58  
lbs.  
kg.  
31  
lbs.  
kg.  
28  
lbs.  
kg.  
32  
X
Y
Z
H
21.00  
[533.4]  
19.00  
[482.6]  
13.00  
[330.2]  
42.36  
[1076.0]  
38AUZ*07  
38AUZ*08  
38AUZ*12  
38AUZ*14  
328 149 128  
353 160 138  
418 190 165  
431 196 162  
68  
72  
85  
82  
62  
65  
78  
92  
70  
78  
90  
95  
19.00  
[482.6]  
23.00  
[584.2]  
13.00  
[330.2]  
42.36  
[1076.0]  
63  
75  
73  
33  
39  
37  
29  
35  
42  
35  
41  
43  
23.00  
[584.2]  
20.00  
[508.0]  
15.00  
[381.0]  
50.36  
[1279.2]  
19.00  
[482.6]  
23.00  
[584.2]  
15.00  
[381.0]  
50.36  
[1279.2]  
Fig. 1 — 38AUZ*07-14 Unit Dimensions  
3
Table 1A — Physical Data — 38AUZ*07-14 Units — 60 Hz English  
UNIT SIZE 38AU  
Z*07  
Z*08  
Z*12  
Z*14  
6
7.5  
10  
12.5  
NOMINAL CAPACITY (tons)  
OPERATING WEIGHT (lb)  
Aluminum-Fin Coils (Standard)  
328  
353  
418  
431  
R-410A  
Scroll  
REFRIGERANT TYPE*  
Operating Charge, Typical (lb)†  
Shipping Charge (lb)  
8.4  
4.4  
10.2  
4.9  
13.8  
6.3  
18.0  
7.3  
COMPRESSOR  
Qty...Model  
Oil Charge (oz)  
No. Cylinders  
Speed (rpm)  
1...ZP61  
56  
1...ZP83  
60  
1...ZP103  
110  
1...ZP137  
110  
N/A  
3500  
CONDENSER FANS  
Qty...Rpm  
Motor Hp  
2...1100  
1
/
4
Diameter  
Nominal Airflow (Cfm Total)  
Watts (Total)  
22  
6000  
610  
1...NOVATION  
CONDENSER COIL (Qty)  
Face Area (sq ft total)  
Rows/Fins per inch (FPI)  
Storage Capacity (lb)**  
17.5  
1/17  
5.5  
20.5  
25.0  
1/17  
7.4  
31.8  
1/17  
8.7  
1/17  
6.0  
CONTROLS  
Pressurestat Settings (psig)  
High Cutout  
Cut-in  
630 ± 10  
505 ± 20  
54 ± 3  
Low Cutout  
Cut-in  
117 ± 5  
PIPING CONNECTIONS (in. ODS)  
Qty...Suction  
Qty...Liquid  
1...11/8  
1...3/8  
1...11/8  
1...1/2  
1...13/8  
1...1/2  
1...13/8  
1...5/8  
LEGEND  
ODS — Outside Diameter Sweat (socket)  
* Unit is factory-supplied with partial charge only.  
† Typical operating charge with 25 ft of interconnecting piping.  
** Storage capacity of condenser coil with coil 80% full of liquid R-410A at 95°F.  
4
Table 1B — Physical Data — 38AUZ*07-14 Units — 60 Hz SI  
UNIT SIZE 38AU  
Z*07  
Z*08  
Z*12  
Z*14  
21.1  
26.4  
35.1  
44  
NOMINAL CAPACITY (kW)  
OPERATING WEIGHT (kg)  
Aluminum-Fin Coils (Standard)  
149  
160  
190  
196  
R-410A  
Scroll  
REFRIGERANT TYPE*  
Operating Charge, Typical (kg)†  
Shipping Charge (kg)  
3.8  
2.0  
4.6  
2.2  
6.3  
2.9  
8.2  
3.3  
COMPRESSOR  
Qty...Model  
Oil Charge (L)  
No. Cylinders  
Speed (r/s)  
1...ZP61  
1.7  
1...ZP83  
1.8  
1...ZP103  
3.3  
1...ZP137  
3.3  
N/A  
58  
CONDENSER FANS  
Qty...r/s  
Motor Hp NEMA  
2...18  
1
/
4
Diameter (mm)  
Nominal Airflow (L/s)  
Watts (Total)  
560  
2832  
610  
1...NOVATION  
CONDENSER COIL (Qty)  
Face Area (sq m total)  
Rows/Fins per Meter (Fins/m)  
Storage Capacity (kg)**  
1.6  
1...670  
2.5  
1.9  
2.3  
1...670  
3.4  
3.0  
1...670  
3.9  
1...670  
2.7  
CONTROLS  
Pressurestat Settings (kPa)  
High Cutout  
Cut-in  
4347 ± 70  
3482 ±138  
372 ± 21  
807 ± 34  
Low Cutout  
Cut-in  
PIPING CONNECTIONS (in. ODS)  
Qty...Suction  
Qty...Liquid  
1...11/8  
1...3/8  
1...11/8  
1...1/2  
1...13/8  
1...1/2  
1...13/8  
1...5/8  
LEGEND  
NEMA — National Electrical Manufacturers Association  
ODS — Outside Diameter Sweat (socket)  
* Unit is factory-supplied with partial charge only.  
† Typical operating charge with 7.62 m of interconnecting piping.  
** Storage capacity of condenser coil with coil 80% full of liquid R-410A at 35°C.  
5
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18  
3
8 A U Z A 0 4 A 0  
6
– 0 A 0 A 0  
G
_____________  
____  
Model Type  
Packaging  
0 = Standard  
1 = LTL  
38AU= Carrier Condensing Unit  
Puronr R---410A Refrigerant  
Type of Coil  
Z = Single Circuit, A/C Scroll Compressor  
Electrical Options  
A = None  
C = Non-Fused Disconnect  
Refrigerant Options  
A = None  
Service Options  
B = Low Ambient  
0 = None  
1 = Un-powered Convenience Outlet  
2 = Powered Convenience Outlet  
Nominal Tonnage  
07 = 6 Tons  
08 = 7.5 Tons  
12 = 10 Tons  
14 = 12.5 Tons  
Not Used  
A = Place Holder  
Base Unit Controls  
Not Used  
0 = Electro-Mechanical Controls  
A = Not Used  
Design Rev  
--- = Catalog Model Number  
Not Used  
0 = Not Used  
Voltage  
1 = 575/3/60  
5 = 208/230/3/60  
6 = 460/3/60  
Coil Options  
G = Al/Al  
Fig. 2 — Model Number Nomenclature  
POSITION NUMBER  
TYPICAL  
1
4
2
8
3
0
4
8
5
G
6
1
7
2
8
3
9
4
10  
5
POSITION  
1−2  
DESIGNATES  
Week of manufacture (fiscal calendar)  
3−4  
Year of manufacture (”08” = 2008)  
5
Manufacturing location (G = ETP, Texas, USA)  
Sequential number  
6−10  
Fig. 3 — Serial Number Nomenclature  
6
• Locate the unit so that the outdoor coil (condenser) air-  
flow is unrestricted on all sides and above.  
.INSTALLATION  
• The unit may be mounted on a level pad directly on the  
base channels or mounted on raised pads at support  
points. See Tables 1A and 1B for unit operating weights.  
See Fig. 1 for weight distribution based on recommended  
support points.  
Jobsite Survey  
Complete the following checks before installation.  
1. Consult local building codes and the NEC (National  
Electrical Code) ANSI/NFPA 70 for special installation  
requirements.  
2. Determine unit location (from project plans) or select unit  
location.  
NOTE: If vibration isolators are required for a particular  
installation, use the data in Fig. 1 to make the proper  
selection.  
3. Check for possible overhead obstructions which may in-  
terfere with unit lifting or rigging.  
Step 3 — Prepare Unit Mounting Support  
Slab Mount —  
Provide a level concrete slab that extends a minimum of 6 in.  
(150 mm) beyond unit cabinet. Install a gravel apron in front of  
condenser coil air inlet to prevent grass and foliage from  
obstructing airflow.  
Step 1 — Plan for Unit Location  
Select a location for the unit and its support system (pad, rails  
or other) that provides for the minimum clearances required for  
safety. This includes the clearance to combustible surfaces, unit  
performance and service access below, around and above unit  
as specified in unit drawings. See Fig. 4.  
Step 4 — Rig and Mount the Unit  
NOTE: Consider also the effect of adjacent units on airflow  
performance and control box safety clearance.  
Do not install the outdoor unit in an area where fresh air supply  
to the outdoor coil may be restricted or when recirculation from  
the condenser fan discharge is possible. Do not locate the unit  
in a well or next to high walls.  
UNIT DAMAGE HAZARD  
Failure to follow this caution may result in equipment  
damage.  
All panels must be in place when rigging. Unit is not  
designed for handling by fork truck.  
Evaluate the path and required line length for interconnecting  
refrigeration piping, including suction riser requirements (out-  
door unit above indoor unit), liquid line lift (outdoor unit below  
indoor unit) and hot gas bypass line. Relocate sections to mini-  
mize the length of interconnecting tubing.  
.
RIGGING — These units are designed for overhead rigging.  
Refer to the rigging label for preferred rigging method. Spread-  
er bars are not required if top crating is left on the unit. All pan-  
els must be in place when rigging. As further protection for coil  
faces, plywood sheets may be placed against the sides of the  
unit, behind cables. Run cables to a central suspension point so  
that the angle from the horizontal is not less than 45 degrees.  
Raise and set the unit down carefully.  
DO NOT BURY REFRIGERATION LINES.  
Although unit is weatherproof, avoid locations that permit  
water from higher level runoff and overhangs to fall onto the  
unit.  
If it is necessary to roll the unit into position, mount the unit on  
longitudinal rails, using a minimum of 3 rollers. Apply force to  
the rails, not the unit. If the unit is to be skidded into position,  
place it on a large pad and drag it by the pad. Do not apply any  
force to the unit.  
RIGHT:  
Min 18” (457 mm)  
REAR:  
requried for service  
Min 18” (457 mm)  
requried for service  
Raise from above to lift the unit from the rails or pad when unit  
is in its final position.  
After the unit is in position, remove all shipping materials and  
top crating.  
LEFT:  
Min 18” (457 mm)  
FRONT:  
requried for service  
42” (1067 mm)  
Step 5 — Complete Refrigerant Piping  
Connections  
Note: Observe requirements for 39” (914 mm) operating clearance  
on either Left or Rear coil opening.  
IMPORTANT: Do not bury refrigerant piping underground.  
Fig. 4 — Service Clearance Dimensional Drawing  
Step 2 — Complete Pre-Installation Checks  
IMPORTANT: A refrigerant receiver is not provided with  
the unit. Do not install a receiver.  
CHECK UNIT ELECTRICAL CHARACTERISTIC —  
Confirm before installation of unit that voltage, amperage and  
circuit protection requirements listed on unit data plate agree  
with power supply provided.  
UNCRATE UNIT — Remove unit packaging except for the  
top skid assembly, which should be left in place until after the  
unit is rigged into its final location.  
PROVIDE SAFETY RELIEF — The 38AUZ unit is provided  
with a fusible joint in the suction line in accordance with  
applicable UL standards for pressure relief. If local codes  
dictate an additional safety relief device, purchase locally and  
install locally. Installation will require the recovery of the  
factory shipping charge before the factory tubing can be cut  
and the supplemental relief device is installed.  
INSPECT SHIPMENT — File a claim with shipping compa-  
ny if the shipment is damaged or incomplete.  
SIZE REFRIGERANT LINES — Consider the linear length  
of piping required between the outdoor unit and indoor unit  
(evaporator), the amount of liquid lift (indoor section installed  
above the outdoor section), and compressor oil return.  
Consider and identify also the arrangement of the tubing path  
(quantity and type of elbows in both lines), liquid line solenoid  
size, filter drier and any other refrigeration specialties located  
CONSIDER SYSTEM REQUIREMENTS  
• Consult local building codes and National Electrical  
Code (NEC, U.S.A.) for special installation requirements.  
• Allow sufficient space for airflow clearance, wiring,  
refrigerant piping, and servicing unit. See Fig. 1 for unit  
dimensions and weight distribution data.  
7
Table 3 — Refrigerant Piping Sizes —  
38AUZ*07-14 60 Hz Units  
in the liquid line. Refer to the indoor unit installation  
instructions for additional details.  
Determine equivalent line length adjustments for path and  
components and add to linear line lengths. See Tables 2 and 3;  
also refer to Part 3 of the Carrier System Design Manual and  
E20-II® software for design details and line sizing.  
LINEAR LENGTH OF INTERCONNECTING PIPING —  
FT (m)  
0-25  
25-50  
(7.5-15)  
50-75  
(15-23)  
75-100  
(23-30)*  
UNIT  
38AU  
(0-7.5)  
Line Size (in. OD)  
Suction line sizing – Select a tube size that produces a suction  
pressure drop in range of 1.5 to 3.0°F (0.8 to 1.7°C). (Higher  
pressure drops are permissible but there will be a loss in  
cooling capacity due to the higher pressure drop.) Insulate the  
suction line.  
Liquid line sizing – For linear line lengths up to 50-ft (15 m),  
select a tube size that produces a liquid pressure drop of  
approximately 2°F (1.1°C). For linear line lengths greater than  
50-ft (15 m), select a line size that will permit the liquid  
state-point subcooling entering the indoor coil’s TXV to be a  
minimum of 2°F (1.1°C).  
Hot Gas Bypass – Hot gas bypass, if used, should be  
introduced before the evaporator. (A bypass route that also  
bypasses the evaporator circuit may lead to oil trapping in the  
evaporator circuit during low load conditions and then to oil  
slugging as evaporator load increases.) Model 38AUZA units  
do not include a hot gas stub connection; a tee must be field-  
supplied and installed in the compressor discharge line. Run a  
½-in OD line between outdoor unit and evaporator coil inlet.  
Install an Auxiliary Side Connector at the evaporator between  
TXV and distributor (follow instructions for the side connector  
part). Insulate the hot gas line.  
L
S
L
S
L
S
L
S
3
3
/
/
/
/
11/8  
11/8  
13/8  
13/8  
/
/
/
/
11/8  
11/8  
13/8  
13/8  
/
/
/
/
11/8  
11/8  
13/8  
13/8  
/
/
/
/
11/8  
13/8  
13/8  
13/8  
3
3
1
1
1
Z*07  
Z*08  
Z*12  
Z*14  
8
8
2
2
8
2
2
2
8
2
2
2
8
2
2
2
3
1
1
1
1
1
1
1
1
LEGEND  
L — Liquid Line  
S — Suction Line  
*Field-supplied suction accumulator required for pipe length 75-100 ft  
(23-30 m).  
NOTES:  
1. Pipe sizes are based on a 2°F (1°C) saturated temperature  
loss for liquid and suction lines.  
2. Pipe sizes are based on the maximum linear length, shown for  
each column, plus a 50% allowance for fittings.  
3. Charge unit with R-410A and verify that subcooled liquid exists  
at TXV by checking for a full liquid line sight glass or by calcu-  
lating subcooling at TXV.  
INSTALL FILTER DRIER(S) AND MOISTURE  
INDICATOR(S) — Every unit should have a filter drier and a  
liquid-moisture indicator (sight glass). Refer to Table 4. In  
some applications, depending on space and convenience re-  
quirements, it may be desirable to install 2 filter driers and sight  
glasses. One filter drier and sight glass may be installed at A  
locations in Fig. 5; or, 2 filter driers and sight glasses may be  
installed at B locations.  
Select the filter drier for maximum unit capacity and minimum  
pressure drop. Complete the refrigerant piping from the indoor  
unit to the outdoor unit before opening the liquid and suction  
lines at the outdoor unit.  
Note that refrigerant suction piping should be insulated.  
IMPORTANT: For 38AUZ*07-14 applications with liquid  
5
lift greater than 20 ft (6 m), use / -in. liquid line.  
8
Maximum lift is 60 ft (18 m).  
Table 2 — Liquid Line Data —  
38AUZ*07-14 60 Hz Units,  
LIQUID LINE  
INSTALL LIQUID LINE SOLENOID VALVE —  
MAXIMUM  
ALLOWABLE  
LIQUID LIFT  
ft (m)  
Maximum  
Allowable  
Pressure  
Drop  
Maximum  
Allowable  
Temp.  
SOLENOID DROP — It is recommended that a solenoid  
valve be placed in the main liquid line (see Fig. 5) between the  
condensing unit and the evaporator coil. Refer to Table 4. (A  
liquid line solenoid valve is required when the liquid line  
length exceeds 75 ft [23 m] or when the condensing unit is con-  
nected to a chiller barrel in a built-up chiller system.) This  
valve prevents refrigerant migration (which causes oil dilution)  
to the compressor during the off cycle, at low outdoor ambient  
temperatures. Wire the solenoid in parallel with the compressor  
contactor coil (see Fig. 5). This means of electrical control is  
referred to as solenoid drop control.  
Loss  
psig (kPa)  
°F (°C)  
60 (18)  
7 (48)  
2 (1)  
*Inlet and outlet.  
NOTE: Data shown is for units operating at 45°F (7.2°C) saturated  
suction temperature and 95°F (35°C) entering air temperature. For  
38AUZ*07-14 applications with liquid lift greater than 20 ft (6 m),  
use 5/8-in. liquid line. Maximum lift is 60 ft (18 m).  
INSTALL LIQUID LINE SOLENOID VALVE (Optional)  
— CAPACITY CONTROL — If 2-step cooling is desired,  
place a solenoid valve in the location shown in Fig. 5.  
MAKE PIPING CONNECTIONS — Piping connections at  
the 38AU unit are ball valves with stub tube extensions. Do not  
open the unit service valves until all interconnecting tube braz-  
ing as been completed.  
The stub tube connections include ¼-in SAE service fittings  
with Schrader valve cores (see Fig. 6). Before making any  
brazed connections to the unit service valves, remove both  
Schrader valve caps and cores and save for re-installation. Con-  
nect a source for nitrogen to one of these service fittings during  
tube brazing to prevent the formation of copper oxides inside  
the tubes at brazed joints.  
When connecting the field tubing to the 38AU service valves,  
wrap the valves in wet rags to prevent overheating.  
8
Table 4 — Refrigerant Specialities Part Numbers.  
LIQUID LINE  
SIZE (in.)  
3
LIQUID LINE  
LLSV  
COIL  
SIGHT  
FILTER  
DRIER  
SUCTION LINE  
UNIT  
SOLENOID VALVE (LLSV)  
GLASS  
ACCUMULATOR  
38AUZ*07  
/
/
/
/
/
200RB5T3M  
200RB5T3M  
200RB5T4M  
200RB6T4M  
200RB6T5M  
AMG/24V  
AMG/24V  
AMG/24V  
AMG/24V  
AMG/24V  
AMI-1TT3  
AMI-1TT3  
AMI-1TT4  
AMI-1TT4  
AMI-1TT5  
P502-8304S*  
P502-8304S*  
P502-8304S  
P502-8307S*  
P502-8307S*  
S-7063S*  
S-7063S*  
S-7063S*  
S-7063  
8
8
2
2
8
3
1
1
5
38AUZ*08  
38AUZ*12  
38AUZ*14  
S-7063  
*Bushings required.  
UNIT OPERATION AND SAFETY HAZARD  
Failure to follow this warning could cause personal injury,  
death and/or equipment damage.  
Puron® (R-410A) refrigerant systems operate at higher  
pressures than standard R-22 systems. Do not use R-22  
service equipment or components on Puron refrigerant  
equipment.  
PRELIMINARY CHARGE — Before starting the unit, charge  
R-410A liquid refrigerant into the high side of the system  
through the liquid service valve. The amount of refrigerant  
added must be at least 80% of the operating charge listed in the  
Physical Data table (Tables 1A and 1B, pages 4 and 5) LESS  
the factory charge quantity (if factory shipping charge has not  
been removed). Allow high and low side pressures to equalize.  
If pressures do not equalize readily, charge R-410A vapor  
(using special service manifold with expansion device) into the  
suction line service port for the low side of system to assure  
charge in the evaporator. Refer to GTAC II, Module 5,  
Charging, Recover, Recycling, and Reclamation for liquid  
charging procedures.  
LEGEND  
TXV — Thermostatic Expansion Valve  
Fig. 5 — Location of Sight Glass(es)  
and Filter Driers  
Step 6 — Install Accessories  
Accessories requiring modifications to unit wiring should be  
completed now. These accessories may include Winter Start  
controls, Low Ambient controls, phase monitor, Compressor  
LOCout. Refer to the instructions shipped with the accessory.  
Field Service  
Access Port  
Factory  
High-Flow  
Access Port  
(Schrader core)  
Step 7 — Complete Electrical Connections  
Service Valve  
with Stem Cap  
Sweat  
Connection  
ELECTRICAL SHOCK HAZARD  
Failure to follow this warning could result in personal  
injury or death.  
Fig. 6 — Typical Piping Connection Assembly  
Pressure-test all joints from outdoor unit connections over to  
the evaporator coil, using nitrogen as pressure and with soap-  
and-bubbles.  
When pressure-testing is completed, remove the nitrogen  
source at the outdoor unit service valves and re-install the two  
Schrader valve cores. Torque the cores to 2-3 in-lbs (23-34  
N-cm).  
EVACUATION/DEHYDRATION — Evacuate and dehydrate  
the connected refrigeration system (excluding the 38AU unit)  
to 500 microns using a two-stage vacuum pump attached to the  
service ports outside the 38AU service valves, following de-  
scription in GTAC II, Module 4, System Dehydration.  
Do not use gas piping as an electrical ground. Unit cabinet  
must have an uninterrupted, unbroken electrical ground to  
minimize the possibility of personal injury if an electrical  
fault should occur. This ground may consist of electrical  
wire connected to unit ground lug in control compartment,  
or conduit approved for electrical ground when installed in  
accordance with NEC (National Electrical Code); ANSI/  
NFPA 70, latest edition (in Canada, Canadian Electrical  
Code CSA [Canadian Standards Association] C22.1), and  
local electrical codes.  
NOTE: Check all factory and field electrical connections  
for tightness. Field-supplied wiring shall conform with the  
limitations of 63°F (33°C) rise.  
Field Power Supply —  
If equipped with optional Powered Convenience Outlet: The  
power source leads to the convenience outlet's transformer  
primary are not factory connected. Installer must connect these  
9
leads according to required operation of the convenience outlet.  
If an always-energized convenience outlet operation is desired,  
connect the source leads to the line side of the unit-mounted  
disconnect. (Check with local codes to ensure this method is  
acceptable in your area.) If a de-energize via unit disconnect  
switch operation of the convenience outlet is desired, connect  
the source leads to the load side of the unit disconnect. On a  
unit without a unit-mounted disconnect, connect the source  
leads to the factory connection leads (pigtails) in the unit’s  
main control box (see Fig. 8).  
All units -  
All field wiring must comply with NEC and all local codes.  
Size wire based on MCA (Minimum Circuit Amps) on the unit  
informative plate. See Fig. 8 for power wiring connections to  
the unit power terminal block and equipment ground.  
Provide a ground-fault and short-circuit over-current protection  
device (fuse or breaker) per NEC Article 440 (or local codes).  
Refer to unit informative data plate for MOCP (Maximum  
Over-current Protection) device size.  
All units except 208/230-v units are factory wired for the  
voltage shown on the nameplate. If the 208/230-v unit is to be  
connected to a 208-v power supply, the control transformer  
must be rewired by moving the black wire with the ¼-in. female  
spade connector from the 230-v connection and moving it to  
the 208-v ¼-in. male terminal on the primary side of the  
transformer. Refer to unit label diagram for to line-side  
information. Field power wires will be connected line-side  
pressure lugs on the power terminal block or at factory-  
installed option non-fused disconnect.  
Splice Terminals  
(field supplied)  
BLK  
YEL  
Field power wires are connected to the unit at the leads to the  
factory connection leads (pigtails) in the unit’s main control  
box (see Fig. 8) or at factory-installed option non-fused  
disconnect switch. Max wire size is #4 AWG (copper only).  
BLU  
NOTE: TEST LEADS - Unit may be equipped with short  
leads (pigtails) on the field line connection points on the  
optional disconnect switch. These leads are for factory  
run-test purposes only; remove and discard before connect-  
ing field power wires to unit connection points.  
DISCONNECT  
Ground Lug  
LEGEND  
Factory Power Connection Lead  
Field Power Supply Conductor  
FIRE HAZARD  
Failure to follow this warning could result in intermittent  
operation or performance satisfaction.  
Fig. 8 — Power Wiring Connections  
Do not connect aluminum wire between disconnect switch  
and condensing unit. Use only copper wire.  
(See Fig. 7.)  
All field wiring must comply with the NEC and local  
requirements.  
Affix the crankcase heater warning sticker to the unit  
disconnect switch.  
Convenience Outlets —  
ELECTRIC  
DISCONNECT  
SWITCH  
ELECTRICAL OPERATION HAZARD  
COPPER  
Failure to follow this warning could result in personal  
injury or death.  
WIRE ONLY  
Units with convenience outlet circuits may use multiple  
disconnects. Check convenience outlet for power status  
before opening unit for service. Locate its disconnect  
switch, if appropriate, and open it. Tag-out this switch, if  
necessary.  
ALUMINUM  
WIRE  
Fig. 7 — Disconnect Switch and Unit  
Units Without Factory-Installed Disconnect —  
Two types of convenience outlets are offered on 38AUZ  
models: Non-powered and unit-powered. Both types provide a  
125-volt GFCI (ground-fault circuit-interrupter) duplex  
receptacle rated at 15-A behind a hinged waterproof access  
cover, located on the end panel of the unit. See Fig. 9.  
When installing units, provide a disconnect switch per NEC  
(National Electrical Code) of adequate size. Disconnect sizing  
data is provided on the unit informative plate. Locate on unit  
cabinet or within sight of the unit per national or local codes.  
Do not cover unit informative plate if mounting the disconnect  
on the unit cabinet.  
Units with Factory-Installed Disconnect —  
The factory-installed option disconnect switch is located in a  
weatherproof enclosure located under the main control box.  
The manual switch handle is accessible through an opening in  
the access panel.  
10  
Convenience  
Outlet  
GFCI  
Pwd-CO  
Fuse  
Switch  
Pwd-CO  
Transformer  
Control Box  
Access Panel  
UNIT  
VOLTAGE  
CONNECT  
AS  
PRIMARY  
CONNECTIONS  
TRANSFORMER  
TERMINALS  
Fig. 9 — Convenience Outlet Location  
208,  
230  
L1: RED + YEL  
L2: BLU + GRA  
H1 + H3  
H2 + H4  
Non-powered type: This type requires the field installation of  
a general-purpose 125-volt 15-A circuit powered from a source  
elsewhere in the building. Observe national and local codes  
when selecting wire size, fuse or breaker requirements and  
disconnect switch size and location. Route 125-v power supply  
conductors into the bottom of the utility box containing the  
duplex receptacle.  
240  
L1: RED  
Splice BLU +  
YEL  
H1  
H2 + H3  
H4  
460  
575  
480  
L2: GRA  
L1: RED  
L2: GRA  
H1  
H2  
600  
Unit-powered type: A unit-mounted transformer is factory-  
installed to stepdown the main power supply voltage to the unit  
to 115-v at the duplex receptacle. This option also includes a  
manual switch with fuse, located in a utility box and mounted  
on a bracket behind the convenience outlet; access is through  
the unit's control box access panel. See Fig. 9.  
The primary leads to the convenience outlet transformer are not  
factory-connected. Selection of primary power source is a  
customer-option. If local codes permit, the transformer primary  
leads can be connected at the line-side terminals on the unit-  
mounted non-fused disconnect or HACR breaker switch; this  
will provide service power to the unit when the unit disconnect  
switch or HACR switch is open. Other connection methods  
will result in the convenience outlet circuit being de-energized  
when the unit disconnect or HACR switch is open. See Fig. 10.  
Duty Cycle: the unit-powered convenience outlet has a duty  
cycle limitation. The transformer is intended to provide power  
on an intermittent basis for service tools, lamps, etc; it is not  
intended to provide 15-amps loading for continuous duty loads  
(such as electric heaters for overnight use). Observe a 50%  
limit on circuit loading above 8-amps (i.e., limit loads  
exceeding 8-amps to 30 minutes of operation every hour).  
Test the GFCI receptacle by pressing the TEST button on the  
face of the receptacle to trip and open the receptacle. Check for  
proper grounding wires and power line phasing if the GFCI  
receptacle does not trip as required. Press the RESET button to  
clear the tripped condition.  
Fig. 10 - Powered Convenience Outlet Wiring  
Fuse on power type: The factory fuse is a Bussman “Fusetron”  
T-15, non-renewable screw-in (Edison base) type plug fuse.  
Using unit-mounted convenience outlets: Units with unit-  
mounded convenience outlet circuits will often require that two  
disconnects be opened to de-energize all power to the unit.  
Treat all units as electrically energized until the convenience  
outlet power is also checked and de-energization is confirmed.  
Observe National Electrical Code Article 210, Branch Circuits,  
for use of convenience outlets.  
Installing Weatherproof Cover –  
A weatherproof while-in-use cover for the factory-installed  
convenience outlets is now required by UL standards. This  
cover cannot be factory-mounted due its depth; it must be  
installed at unit installation. For shipment, the convenience  
outlet is covered with a blank cover plate.  
The weatherproof cover kit is shipped in the unit's control box.  
The kit includes the hinged cover, a backing plate and gasket.  
DISCONNECT ALL POWER TO UNIT AND  
CONVENIENCE OUTLET.  
Remove the blank cover plate at the convenience outlet;  
discard the blank cover.  
Loosen the two screws at the GFCI duplex outlet, until  
approximately 1/2-in (13 mm) under screw heads are exposed.  
Press the gasket over the screw heads. Slip the backing plate  
over the screw heads at the keyhole slots and align with the  
gasket; tighten the two screws until snug (do not over-tighten).  
Mount the weatherproof cover to the backing plate as shown in  
Fig. 11. Remove two slot fillers in the bottom of the cover to  
permit service tool cords to exit the cover. Check for full  
closing and latching.  
11  
COVER – WHILE-IN-USE  
WEATHERPROOF  
RECEPTACLE  
NOT INCLUDED  
Central  
Terminal  
Board  
R
G
X
C
X
Y1  
C
G
G
O/B/Y2  
(Notes 1, 2)  
W2  
W2  
W1  
Y2  
Y1  
R
W1  
Y2  
Y1  
R
C
(Note 3)  
T–STAT  
BASE PLATE FOR  
GFCI RECEPTACLE  
Note 1: Typical multi-function marking. Follow manufacturer’s configuration  
instructions to select Y2.  
Note 2: Y2 to economizer required on single-stage cooling units when  
integrated economizer function is desired  
Note 3: Connect only if thermostat requires 24-vac power source.  
Field Wiring  
Fig. 11 — Weatherproof Cover Installation  
All Units —  
Voltage to compressor terminals during operation must be  
within voltage range indicated on unit nameplate. See Table 5.  
On 3-phase units, voltages between phases must be balanced  
within 2% and the current within 10%. Use the formula shown  
in the legend for Table 5, Note 5 (see page 13) to determine the  
percent of voltage imbalance. Operation on improper line  
voltage or excessive phase imbalance constitutes abuse and  
may cause damage to electrical components. Such operation  
would invalidate any applicable Carrier warranty.  
Field Control Wiring — Unit control voltage is 24 v. See  
Fig. 8 and the unit’s label diagram for field-supplied wiring  
details. Route control wires through the opening in unit’s end  
panel to the connections terminal board in the unit’s control  
box.  
Fig. 12 — Typical Remote Thermostat Connections  
CONTROL CIRCUIT WIRING — Control voltage is 24 v.  
See Fig. 8 and the unit’s label diagram for field-supplied  
wiring details. Route control wires through the opening in  
unit’s end panel to the connection in the unit’s control box.  
CONTROL TRANSFORMER WIRING (38AUZ07-14  
Units) — On multivoltage units, check the transformer  
primary wiring connections. See Fig. 13 or refer to the unit’s  
label diagram.  
If the unit will be operating at 208-3-60 power, remove the  
black wire (BLK) from the transformer primary connection  
labelled “230” and move it to the connection labelled “208”.  
See Fig. 13.  
The 38AUZ unit requires an external temperature control  
device. This device can be a thermostat (field-supplied) or a  
PremierLink controller (available as factory-installed option or  
as field-installed accessory, for use on a Carrier Comfort  
Network or as a stand alone control).  
Thermostat —  
Install a Carrier-approved accessory thermostat according to  
installation instructions included with the accessory. For  
complete economizer function, select a two—stage cooling  
thermostat. Locate the thermostat accessory on a solid wall in  
the conditioned space to sense average temperature in  
accordance with the thermostat installation instructions.  
If the thermostat contains a logic circuit requiring 24-v power,  
use a thermostat cable or equivalent single leads of different  
colors with minimum of four leads. If the thermostat does not  
require a 24-v source (no “C” connection required), use a  
thermostat cable or equivalent with minimum of three leads.  
Check the thermostat installation instructions for additional  
features which might require additional conductors in the  
cable.  
Fig. 13 — Control Transformer Wiring  
For wire runs up to 50 ft. (15 m), use no. 18 AWG (American  
Wire Gage) insulated wire (35°C minimum). For 50 to 75 ft.  
(15 to 23 m), use no. 16 AWG insulated wire (35°C minimum).  
For over 75 ft. (23 m), use no. 14 AWG insulated wire (35°C  
minimum). All wire sizes larger than no. 18 AWG cannot be  
directly connected to the thermostat and will require a junction  
box and splice at the thermostat.  
PremierLink (accessory installation) – Refer to Form 33CS-  
58SI for details on connecting the PremierLink controller and  
its various sensors.  
12  
Table 5 — Electrical Data — 38AUZ*07-14 60 Hz Units  
NOMINAL  
VOLTAGE  
VOLTAGE  
RANGE*  
FAN MOTORS  
(Qty 2)  
POWER  
SUPPLY  
UNIT  
SIZE  
38AU  
FACTORY-  
INSTALLED  
OPTION  
COMPRESSOR  
V-Ph-Hz  
MIN  
MAX  
RLA  
LRA  
FLA (ea)  
LRA (ea)  
MCA  
MOCP  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
208/230-3-60  
187  
414  
518  
187  
414  
518  
187  
414  
518  
187  
414  
518  
253  
506  
633  
253  
506  
633  
253  
506  
633  
253  
506  
633  
19  
123  
1.5  
0.8  
0.6  
1.5  
0.8  
0.6  
1.5  
0.8  
0.6  
1.5  
0.8  
0.6  
3.7  
25.2  
12.9  
9.9  
45  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
460-3-60  
575-3-60  
9.7  
7.4  
62  
50  
1.9  
1.6  
3.7  
1.9  
1.6  
3.7  
1.9  
1.6  
3.7  
1.9  
1.6  
20  
15  
50  
25  
20  
60  
30  
25  
80  
30  
30  
Z*07  
Z*08  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
208/230-3-60  
460-3-60  
25  
164  
100  
78  
32.7  
16.0  
11.8  
39.1  
21.7  
15.8  
61.6  
24.0  
19.0  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
12.2  
9.0  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
575-3-60  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
208/230-3-60  
460-3-60  
30.1  
16.7  
12.2  
48.1  
18.6  
14.7  
225  
114  
80  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
Z*12  
Z*14  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
575-3-60  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
208/230-3-60  
460-3-60  
245  
125  
100  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
NONE OR DISCONNECT  
CONVENIENCE OUTLET  
575-3-60  
LEGEND  
5. Unbalanced 3-Phase Supply Voltage  
FLA  
Full Load Amps  
Locked Rotor Amps  
Minimum Circuit Amps  
Never operate a motor where a phase imbalance in supply voltage is  
greater than 2%. Use the following formula to determine the percentage  
of voltage imbalance.  
LRA  
MCA  
max voltage deviation from average voltage  
Maximum Overcurrent  
Protection  
National Electrical Code  
Rated Load Amps  
MOCP —  
% Voltage Imbalance = 100 x  
average voltage  
NEC  
RLA  
Example: Supply voltage is 230-3-60  
AB = 224 v  
BC = 231 v  
AC = 226 v  
*Units are suitable for use on electrical systems where voltage supplied to  
the unit terminals is not below or above the listed limits.  
NOTES:  
1. The MCA and MOCP values are calculated in accordance with the NEC,  
Article 440.  
(224 + 231 + 226)  
3
681  
3
2. Motor RLA and LRA values are established in accordance with Underwriters’  
Laboratories (UL), Standard 1995.  
Average Voltage =  
=
=
3. The 575-v units are UL, Canada-listed only.  
4. Convenience outlet is available as a factory-installed option and is 115-v,  
1 ph, 60 Hz.  
227  
Determine maximum deviation from average voltage.  
(AB) 227 – 224 = 3 v  
(BC) 231 – 227 = 4 v  
(AC) 227 – 226 = 1 v  
Maximum deviation is 4 v.  
Determine percent of voltage imbalance.  
4
% Voltage Imbalance  
= 100 x  
= 1.76%  
227  
This amount of phase imbalance is satisfactory as it is below the  
maximum allowable 2%.  
IMPORTANT: If the supply voltage phase imbalance is more than  
2%, contact your local electric utility company immediately.  
13  
PRE-START-UP  
START-UP  
IMPORTANT: Before beginning Pre-Start-Up or Start-Up,  
review Start-Up Checklist at the back of this book. The  
Checklist assures proper start-up of a unit and provides a  
record of unit condition, application requirements, system  
information, and operation at initial start-up.  
38AUZ Units — The compressor crankcase heater must be  
on for 24 hours before start-up. After the heater has been on for  
24 hours, the unit can be started. If no time elapsed since the  
preliminary charge step was completed, it is unnecessary to  
wait the 24-hour period.  
PRELIMINARY CHECKS  
1. Check that electric power supply agrees with unit  
nameplate data.  
2. Verify that the compressor crankcase heater is securely in  
place.  
3. Check that the compressor crankcase heater has been on  
at least 24 hours.  
4. Recheck for leaks using the procedure outlined in the  
Pre-Start-Up section, Leak Test and Dehydration. If any  
leaks are detected, repair as required. Evacuate and  
dehydrate as described in the Leak Test and Dehydration  
section.  
5. Ensure that the preliminary charge has been added as  
described in the Pre-Start-Up section, Preliminary  
Charge.  
UNIT DAMAGE HAZARD  
Do not attempt to start the condensing unit, even  
momentarily, until the following steps have been  
completed. Compressor damage may result.  
System Check  
1. Check all air handler(s) and other equipment auxiliary  
components. Consult the manufacturer’s instructions  
regarding any other equipment connected to the con-  
densing unit. If the unit has field-installed accessories,  
be sure all are properly installed and correctly wired. If  
used, the airflow switch must be properly installed.  
2. Be sure the unit is properly leak checked and dehydrated.  
3. Check tightness of all electrical connections.  
4. Open the liquid line and suction line service valves.  
5. Be sure the unit is properly charged. See “Preliminary  
Charge”, on page 9.  
6. The electrical power source must agree with the unit’s  
nameplate rating.  
7. The crankcase heater must be firmly attached to the com-  
pressor crankcase. Be sure the crankcase is warm (heater  
must be on for 24 hours before starting compressor).  
6. All internal wiring connections must be tight, and all  
barriers and covers must be in place.  
NOTE: The 38AUZ units are factory charged with the  
required amount of oil. If recharging in required, use Emka-  
rate RL 32-3MAF for the 38AUZ units.  
COMPRESSOR ROTATION — On 3-phase units with scroll  
compressors, it is important to be certain that the compressor is  
rotating in the proper direction. To determine whether or not  
compressor is rotating in the proper direction:  
1. Connect service gages to the suction and liquid pressure  
fittings.  
2. Energize the compressor.  
3. The suction pressure should drop and the liquid pressure  
should rise, as is normal on any start-up.  
If the suction pressure does not drop and the liquid pressure  
does not rise to normal levels:  
1. Turn off power to the unit, tag disconnect.  
2. Reverse any two of the unit power leads.  
Turn On Crankcase Heater — Turn on the crankcase  
heater for 24 hours before starting the unit to be sure all the  
refrigerant is out of the oil. To energize the crankcase heater,  
proceed as follows:  
1. Set the space thermostat set point above the space tem-  
perature so there is no demand for cooling.  
2. Close the field disconnect.  
Preliminary Charge — Before starting the unit, charge  
liquid refrigerant into the high side of the system through the  
liquid service valve. The amount of refrigerant added must be  
at least 80% of the operating charge listed in the Physical Data  
table (Tables 1A and 1B, pages 4 and 5). Allow high and low  
side pressures to equalize before starting compressor. If  
pressures do not equalize readily, charge vapor on low side of  
system to assure charge in the evaporator. Refer to GTAC II,  
Module 5, Charging, Recover, Recycling, and Reclamation for  
liquid charging procedures.  
3. Reapply power to the compressor, verify correct  
pressures.  
The suction and liquid pressure levels should now move to  
their normal start-up levels.  
COMPRESSOR OVERLOAD — This overload interrupts  
power to the compressor when either the current or internal  
motor winding temperature becomes excessive, and automati-  
cally resets when the internal temperature drops to a safe level.  
This overload may require up to 60 minutes (or longer) to reset.  
If the internal overload is suspected of being open, disconnect  
the electrical power to the unit and check the circuit through the  
overload with an ohmmeter or continuity tester.  
UNIT DAMAGE HAZARD  
Prior to starting compressor, a preliminary charge of  
refrigerant must be added to avoid possible compressor  
damage.  
14  
ADVANCED SCROLL TEMPERATURE PROTECTION  
(ASTP) — Advanced Scroll Temperature Protection (ASTP)  
is a form of internal discharge temperature protection, used in  
38AUZ*12 and 38AUZ*14 units, that unloads the scroll com-  
pressor when the internal temperature reaches approximately  
300°F. At this temperature, an internal bi-metal disk valve  
opens and causes the scroll elements to separate, which stops  
compression. Suction and discharge pressures balance while  
the motor continues to run. The longer the compressor runs un-  
loaded, the longer it must cool before the bi-metal disk resets.  
See Fig. 14.  
START UNIT — The field disconnect is closed, the indoor  
fan circuit breaker is closed, and the space thermostat is set  
above ambient so that there is no demand for cooling. Only the  
crankcase heater will be energized.  
Reset the space thermostat below ambient so that a call for  
cooling is ensured.  
Never charge liquid into the low-pressure side of system.  
Do not overcharge. During charging or removal of refriger-  
ant, be sure indoor-fan system is operating. Ensure both  
outdoor fan motors are running; bypass any Motormaster  
function.  
120  
110  
100  
90  
80  
70  
60  
50  
40  
30  
20  
10  
0
ADJUST REFRIGERANT CHARGE — The unit must be  
charged in Cooling mode only. Refer to Cooling Charging  
Charts, Fig. 16 through Fig. 19. For applications with line  
lengths greater than 100 ft, contact Carrier representative. Vary  
refrigerant until the conditions of the chart are met. Note that  
the charging charts are different from the type normally used.  
The charts are based on charging the units to the correct sub-  
cooling for the various operating conditions. Accurate pressure  
gage and temperature sensing device are required. Connect the  
pressure gage to the service port on the liquid line service  
valve. Mount the temperature sensing device on the liquid line  
close to the liquid line service valve, and insulate it so that out-  
door ambient temperature does not affect the reading. Indoor  
airflow must be within the unit’s normal operating range. Oper-  
ate the unit for a minimum of 15 minutes. Ensure that pressure  
and temperature readings have stabilized. Plot the liquid pres-  
sure and temperature on chart and add or reduce the charge to  
meet the curve. Adjust the charge to conform with the charging  
chart, using the liquid pressure and temperature to read the  
chart.  
0
10  
20  
30  
40  
50  
60  
70  
80  
90  
Compressor Unloaded Run Time (Minutes)  
*Times are approximate.  
NOTE: Various factors, including high humidity, high ambient tem-  
perature, and the presence of a sound blanket will increase cool-  
down times.  
Fig. 14 — Recommended Minimum Cool-Down Time  
After Compressor is Stopped  
To manually reset ASTP, the compressor should be stopped  
and allowed to cool. If the compressor is not stopped, the motor  
will run until the motor protector trips, which occurs up to  
90 minutes later. Advanced Scroll Temperature Protection will  
reset automatically before the motor protector resets, which  
may take up to 2 hours. A label located above the terminal box  
identifies Copeland Scroll compressor models (ZP103 and  
ZP137) that contain this technology. See Fig. 15.  
FINAL CHECKS — Ensure that all safety controls are  
operating, control panel covers are on, and the service panels  
are in place.  
Fig. 15 — Advanced Scroll Temperature  
Protection Label  
15  
Fig. 16 — 38AUZ*07 Charging Chart  
Fig. 17 — 38AUZ*08 Charging Chart  
Fig. 18 — 38AUZ*12 Charging Chart  
16  
Fig. 19 — 38AUZ*14 Charging Chart  
Fig. 20 — 38AU Wiring Diagram  
17  
OPERATING SEQUENCE  
ROUTINE SYSTEM MAINTENANCE  
These items should be part of a routine maintenance program,  
to be checked every month or two, until a specific schedule for  
each can be identified for this installation:  
Base Unit Controls  
Indoor (Supply) Fan  
The indoor fan contactor (IFC) is remotely located at the fan  
coil or fan section. If the thermostat fan operation is selected as  
Continuous, the IFC is energized and the indoor (supply) fan  
motor runs continuously. If the thermostat fan operation is  
selected as Automatic, the IFC will be energized on a call for  
Cooling; indoor (supply) fan motor runs. When thermostat call  
for Cooling is satisfied, the IFC is de-energized and indoor  
(supply) fan motor stops.  
Quarterly Inspection (and 30 days after initial  
start)  
Indoor section  
• Condenser coil cleanliness checked.  
• Return air filter replacement  
• Outdoor hood inlet filters cleaned  
• Belt tension checked  
Cooling, Unit Without Economizer  
• Belt condition checked  
On a thermostat call for Cooling, IFC will be energized and  
indoor (supply) fan motor runs. Thermostat contact TC1  
closes; terminal Y1 at 38AU unit receives 24-v. 24-v received  
at CADM terminal Y. If anti-recycle time delay period has not  
expired, CADM relay will remain open, preventing  
compressor start. When safety pressure switches are closed, the  
liquid line solenoid valve opens. When CADM time delay  
expires, the compressor contactor is energized; both outdoor  
fan motors start and compressor starts.  
When space cooling load is satisfied, thermostat contacts TC1  
open, removing 24-v at 38AU terminal Y. Compressor and  
outdoor fan motors stop. Liquid line solenoid valve is  
de-energized and valve closes. CADM begins its three-minute  
anti-recycle time delay.  
If either the Low Pressure Switch or High Pressure Switch  
opens while thermostat contact TC1 remains closed, the  
compressor contactor is de-energized (both fan motors and  
compressor stop) and liquid line solenoid is de-energized  
(valve closes). CADM initiates a TRIP event (cooling demand  
sensed at CADM terminal Y but no current is measured at T1,  
T2, T3 motor sensors); CADM relay opens and RED LED is  
illuminated. TRIP condition maintains lockout of compressor  
operation until CADM is manually reset. Reset CADM by  
cycling unit main power.  
• Pulley alignment checked  
• Fan shaft bearing locking collar tightness checked  
• Condensate drain checked  
Seasonal Maintenance  
These items should be checked at the beginning of each season  
(or more often if local conditions and usage patterns dictate):  
Air Conditioning  
• Condenser fan motor mounting bolts tightness  
• Compressor mounting bolts  
• Condenser fan blade positioning  
• Control box cleanliness and wiring condition  
• Wire terminal tightness  
• Refrigerant charge level  
• Evaporator coil cleaning  
• Evaporator blower motor amperage  
Heating  
• Power wire connections  
• Fuses ready  
• Manual-reset limit switch is closed  
Complete system shutdown may be caused by loss of main  
power, open compressor internal overload, open low-pressure  
or high-pressure switch, or a fault detected by the CADM  
logic. Compressor operation without cooling may indicate the  
compressor’s ASTP feature is active (unit sizes 12 and 14  
only); disconnect unit power and allow compressor to cool. See  
Service section for further details.  
Economizer or Outside Air Damper  
• Inlet filters condition  
• Check damper travel (economizer)  
• Check gear and dampers for debris and dirt  
Cooling, Unit With Economizer  
Refer to fan coil unit installation instructions and economizer  
accessory installation instructions for operating sequences  
when system is equipped with accessory economizer.  
Heating  
Refer to fan coil unit installation instructions and accessory  
heating device installation instructions for operating sequences  
in heating mode.  
18  
SERVICE  
POWER  
(GRN)  
Comfort Alert Diagnostic Module  
The Comfort Alert Diagnostic Module (CADM) monitors and  
®
analyzes data from the Copeland Scroll three-phase compres-  
sor and the thermostat demand. The CADM also provides a  
3-minute anti-recycle time delay to compressor cycling.  
The CADM detects causes for electrical and system related  
failures without any sensors. Flashing LEDs communicate the  
Alert codes to guide service technicians in accurately and  
quickly troubleshooting the system and determining root cause  
for the failure.  
ALERT  
(YEL)  
Inputs to the CADM include 24-vac power, thermostat Y1,  
compressor contactor coil (common side) and compressor  
power leads (from the compressor contactor).  
TRIP  
(RED)  
Input  
Terminal Voltage  
Control  
Power  
Control  
Common  
Cooling  
Contactor  
Coil  
Line A  
Line B  
Line C  
Fig. 21 — CADM Housing/LED Locations  
R
24-V  
The ALERT LED indicates an abnormal condition exists in the  
system through a flash code. The ALERT LED will blink a  
number of times consecutively, pause and the repeat the  
process. The number of blinks, defined in Table 6, correlates to  
a particular abnormal condition; troubleshooting tips are  
provided for each Alert code. Reset of the ALERT may be  
automatic or manual. If the fault condition causing the Alert is  
self-corrected, the Alert code will be removed and the CADM  
will automatically reset and allow the system to restart  
normally. Manual reset requires that main power to the 38AU  
unit be recycled after the cause for the Alert condition has been  
detected and corrected.  
The TRIP LED indicates either a time-delay period is currently  
active (RED LED is blinking) or the module has locked out the  
compressor (RED LED is on steady). A lockout condition will  
occur when the CADM detects a thermostat demand at input Y  
but there is no power at the compressor line terminals T1 or T2  
or T3. This lockout can occur due to a safety switch (LPS or  
HPS) opening and de-energizing the compressor contactor, the  
compressor-motor internal overload opens, or other internal  
power interruption has occurred. Reset of the TRIP LED  
requires that unit main power be recycled after the loss of  
power to the compressor condition has been detected and  
corrected.  
C
Y
P
24-V  
24-V  
24-V  
T1  
T2  
T3  
Line  
Line  
Line  
Control of the compressor contactor coil is through a  
normally-closed (power on the module) contact between  
terminals P and C.  
Communications of status and alert conditions is through three  
LEDs located on the top edge of the module housing (see Fig.  
21): POWER (green), ALERT (yellow), and TRIP (red).  
The POWER LED indicates the presence of control power to  
the CADM.  
Simultaneous Blinking of YELLOW and RED LEDs indicates  
control power input to the CADM is low. Check control circuit  
transformer and wiring.  
Troubleshooting the CADM Wiring – Flashing LEDs also  
indicate wiring problems to the CADM. See Table 7 for  
discussion of additional LED flash codes and troubleshooting  
instructions.  
19  
Table 6 — LED Status Codes  
Status LED  
Status LED Description  
Status LED Troubleshooting Information  
Green “POWER” Module has power  
Supply voltage is present at module terminals  
Red “TRIP”  
LED On Solid  
Thermostat demand signal Y 1. Compressor protector is open  
is present, but the  
2. Condensing unit power disconnect is open  
3. Compressor circuit breaker or fuse(s) is open  
compressor is not running.  
4. Broken supply wires or connector is not  
making contact  
5. Compressor power wires not routed through  
Comfort Alert  
6. Compressor contactor has failed open  
Red “TRIP” LED The anti-short cycle timer (3 minutes), in module is preventing compressor  
Flashing restart.  
Module locks out compressor when compressor damaging ALERT code appears.  
Lockout ALERT codes are noted in the Status LED Description.  
During a compressor lock out, 24VAC power must be removed from module to manually reset.  
Yellow “ALERT”  
LED On Solid  
A short circuit or over current 1. Compressor contactor coil shorted  
condition exists on PROT  
2. Electrical load too high for PROT circuit  
terminal.  
(maximum 1 Amp)  
3. 24 V AC wired directly to PROT terminal  
Yellow “ALERT”  
Flash Code 2  
System Pressure Trip  
Discharge pressure out of  
limits or compressor  
overload (if no high pressure  
switch in system)  
1. High head pressure  
2. Condenser coil poor air circulation (dirty,  
blocked, damaged)  
3. Condenser fan is not running  
LOCKOUT  
4. If low pressure switch is open:  
Refer to Code 3 for troubleshooting  
Yellow “ALERT”  
Flash Code 3  
Short Cycling  
Compressor is running only  
briefly LOCKOUT  
1. If low pressure switch is open:  
a. Low refrigerant charge  
b. Evaporator blower is not running  
c. Evaporator coil is frozen  
d. Faulty metering device  
e. Condenser coil is dirty  
f. Liquid line restriction (filter drier blocked if  
present)  
2. If high pressure switch is open, go to Flash  
Code 2 information  
3. Intermittent thermostat demand signal  
4. System or control board defective  
Yellow “ALERT”  
Flash Code 4  
Locked Rotor  
LOCKOUT  
1. Low line voltage to compressor  
2. Excessive liquid refrigerant in compressor  
3. Compressor bearings are seized  
Yellow “ALERT”  
Flash Code 5  
Open Circuit  
1. Condensing unit power disconnect is open  
2. Compressor circuit breaker or fuses are open  
3. Compressor contactor has failed open  
4. High pressure switch is open and requires  
manual reset  
5. Broken supply wires or connector is not  
making contact  
6. Unusually long compressor protector reset  
time due to extreme ambient temperature  
7. Compressor windings are damaged  
1. Compressor fuse is open on one phase  
2. Broken wire or connector on one phase  
3. Compressor motor winding is damaged  
4. Utility supply has dropped one phase  
Yellow “ALERT”  
Flash Code 6  
Missing Phase  
LOCKOUT  
Yellow “ALERT”  
Flash Code 7  
Reverse Phase  
LOCKOUT  
1. Compressor running backward due to supply  
phase reversal  
Yellow “ALERT”  
Flash Code 8  
Welded Contactor  
Compressor always runs  
1. Compressor contactor has failed closed  
2. Thermostat demand signal not connected to  
module  
Yellow “ALERT”  
Flash Code 9  
Low Voltage  
Control circuit < 18VAC  
1. Control circuit transformer is overloaded  
2. Low line voltage to compressor  
20  
Table 7 — CADM Troubleshooting  
Miswired Module Indication  
Recommended Troubleshooting Action  
Green LED is not on,  
module does not power up  
Determine if both R and C module terminals are  
connected. Verify voltage in present at module’s R and C  
terminals.  
NOTE: The CADM requires a constant nominal 24VAC  
power supply. The wiring to the module’s R and C  
terminals must be directly from the control transformer.  
The module cannot receive its power from another device  
that will interrupt the 24VAC power supply. See Fig. 20,  
the 38AU Wiring Diagram.  
Green LED Intermittent,  
module powers up only  
when compressor runs  
Determine if R and Y terminals are wired in reverse. Verify  
module’s R and C terminals have a constant source. See  
NOTE” above for details on R and C wiring.  
TRIP LED is on but system  
and compressor check OK  
Verify Y terminal is wired properly per the 38AU wiring  
diagram (see Fig. 19). Verify voltage at contactor coil falls  
below 0.5VAC when off. Verify 24VAQC is present across  
Y and C when thermostat demand signal is present. If not,  
R and C are reverse wired.  
TRIP LED and ALERT LED  
flashing together  
Verify R and C terminals are supplied with 19-28VAC.  
ALERT Flash Code 3  
(Compressor Short Cycling)  
displayed incorrectly  
Verify Y terminal is connected to 24VAC at contactor coil.  
Verify voltage at contactor coil falls below 0.5VAC when  
off.  
ALERT Flash Code 5 or 6  
(Open Circuit, Missing Phase)  
displayed incorrectly  
Check that compressor T1 and T3 wires are through  
module’s current sensing holes. Verify Y terminal is  
connected to 24VAC at contactor coil. Verify voltage at  
contactor coil falls below 0.5VAC when off.  
Alert Flash Code *  
(Welded Contactor)  
displayed incorrectly  
Determine if module’s Y terminal is connected. Verify Y  
terminal is connected to 24VAC at contactor coil. Verify  
24VAC is present across Y and C when thermostat  
demand signal is present. If not, R and C are reverse  
wired. Verify voltage at contactor coil falls below 0.5VAC  
when off.  
ADVANCED SCROLL TEMPERATURE PROTECTION  
(ASTP) — See “Advanced Scroll Temperature Protection  
(ASTP)” on page 15.  
Crankcase Heater — The heater prevents refrigerant  
migration and compressor oil dilution during shutdown when-  
ever compressor is not operating. The heater is wired to cycle  
with the compressor; the heater is off when compressor is run-  
ning, and on when compressor is off.  
The crankcase heater will operate as long as the power circuit  
is energized.  
Low-Pressure Switch — The 38AUZ low-pressure  
switch is stem-mounted on the suction line. Switches are all  
fixed, non-adjustable type.  
High-Pressure Switch — The 38AUZ high-pres-  
sure switch is stem-mounted on the discharge line. The switch  
is a fixed, non-adjustable type.  
Compressor Protection  
COMPRESSOR OVERTEMPERATURE PROTECTION  
(IP) — A thermostat installed on the compressor motor wind-  
ing reacts to excessively high winding temperatures and shuts  
off the compressor.  
CRANKCASE HEATER — The heater minimizes absorp-  
tion of liquid refrigerant by oil in the crankcase during brief or  
extended shutdown periods. The main disconnect must be on  
to energize the crankcase heater.  
Outdoor Fans — Each fan is supported by a formed-wire  
mount bolted to the fan deck and covered with a wire guard.  
Fan motors have permanently lubricated bearings.  
Lubrication  
FAN MOTORS have sealed bearings. No provisions are made  
for lubrication.  
COMPRESSOR has its own oil supply. Loss of oil due to a  
leak in the system should be the only reason for adding oil after  
the system has been in operation.  
IMPORTANT: Never open any switch or disconnect that  
energizes the crankcase heater unless unit is being serviced  
or is to be shut down for a prolonged period. After a pro-  
longed shutdown on a service job, energize the crankcase  
heater for 24 hours before starting the compressor.  
21  
NOVATION™ Coil Cleaning and Maintenance —  
Repairing NOVATION Condenser Tube Leaks  
To clean the NOVATION condenser coil, chemicals are NOT  
to be used; only water is approved as the cleaning solution.  
Only clean potable water is authorized for cleaning  
NOVATION condensers.  
Clean the coil as follows:  
1. Turn off unit power.  
2. Remove screws holding rear corner posts and top cover  
in place. Pivot top cover up 12 to 18 in. (305 to 457 mm)  
and support with a rigid support. See Fig. 21.  
RCD offers service repair kit Part Number 50TJ660007 for  
repairing tube leaks in the NOVATION coil crosstubes. This kit  
includes approved braze materials (aluminum fluxcore braze  
rods), a heat shield, a stainless steel brush, replacement fin  
segments, adhesive for replacing fin segments, and instructions  
specific to the NOVATION aluminum coil. See EPIC for  
instruction sheet 99TA526379.  
The repair procedure requires the use of MAPP gas and torch  
(must be supplied by servicer) instead of conventional  
oxyacetylene fuel and torch. While the flame temperature for  
MAPP is lower than that of oxyacetylene (and thus provides  
more flexibility when working on aluminum), the flame  
temperature is still higher than the melting temperature of  
aluminum, so user caution is required. Follow instructions  
carefully. Use the heat shield.  
Replacing NOVATION Condenser Coil  
The service replacement coil is preformed and is equipped with  
transition joints with copper stub tubes. When brazing the  
connection joints to the unit tubing, use a wet cloth around the  
aluminum tube at the transition joint. Avoid applying torch  
flame directly onto the aluminum tubing.  
Field Refrigerant Access Ports  
Field service access to refrigerant pressures is through the  
access ports located at the service valves (see Fig. 6). These  
ports are ¼-in SAE Flare couplings with Schrader check valves  
and service caps. Use these ports to admit nitrogen to the field  
tubing during brazing, to evacuate the tubing and evaporator  
coil, to admit initial refrigerant charge into the low-side of the  
system and when checking and adjusting the system refrigerant  
charge. When service activities are completed, ensure the  
service caps are in place and secure; check for leaks. If the  
Schrader check valve must be removed and re-installed, tighten  
to 2-3 in-lbs (23-34 N-cm).  
Fig. 21 — Pivot and Support Top Cover  
3. Carefully remove any foreign objects or debris attached  
to the coil face or trapped within the mounting frame and  
brackets.  
Factory High-Flow Access Ports  
There are two additional access ports in the system - on the  
suction tube between the compressor and the suction service  
valve and on the liquid tube near the liquid service valve (see  
Fig. 6). These are brass fittings with black plastic caps. The  
hose connection fittings are standard ¼-in SAE Male Flare  
couplings.  
The brass fittings are two-piece High Flow valves, with a  
receptacle base brazed to the tubing and an integral spring-  
closed check valve core screwed into the base. (See Fig. 22.)  
This check valve is permanently assembled into this core body  
and cannot be serviced separately; replace the entire core body  
if necessary. Service tools are available from RCD that allow  
the replacement of the check valve core without having to  
recover the entire system refrigerant charge. Apply compressor  
refrigerant oil to the check valve core's bottom o-ring. Install  
the fitting body with 96 ±-10 in-lbs (1085 ±23 N-cm) of  
torque; do not overtighten.  
4. Using a high pressure water sprayer, purge any soap or  
industrial cleaners from hose and/or dilution tank prior to  
wetting the coil.Clean condenser face by spraying the coil  
core steadily and uniformly from top to bottom, directing  
the spray straight into or toward the coil face. Do not  
exceed 900 psig or a 45 degree angle; nozzle must be at  
least 12 in. (30 cm) from the coil face. Reduce pressure  
and use caution to prevent damage to air centers (fins).  
Do not fracture the braze between air centers and  
refrigerant tubes. Allow water to drain from the coil core  
and check for refrigerant leaks prior to startup.  
5. Replace top cover and rear corner posts.  
PERSONAL INJURY HAZARD  
Failure to follow this caution may result in personal injury  
or equipment damage.  
Chemical cleaning should NOT be used on the aluminum  
microchannel condenser. Damage to the coil may occur.  
Only approved cleaning is recommended.  
22  
SEAT  
CORE  
(Part No. EC39EZ067)  
1/2-20 UNF RH  
0.596  
45°  
30°  
WASHER  
O-RING  
DEPRESSOR PERARI720  
1/2" HEX  
+.01/-.035  
.47  
5/8” HEX  
FROM FACE OF BODY  
This surface provides a metal to metal seal when  
torqued into the seat. Appropriate handling is  
required to not scratch or dent the surface.  
7/16-20 UNF RH  
Fig. 22 — CoreMax Access Port Assembly  
FASTENER TORQUE VALUES  
Table 8 — Torque Values  
Compressor mounting bolts  
65–75 in–lbs  
20 ±2 in–lbs  
84 ±2 in–lbs  
96 ±10 in–lbs  
2–3 in–lbs  
(734–847 N–cm)  
(226 ±23 N–cm)  
Condenser fan motor mounting bolts  
Condenser fan hub setscrew  
High-flow service port  
(949 ±136 N–cm)  
(1085 ±23 N–cm)  
(23–34 N–cm)  
Schrader-type service check valve  
TROUBLESHOOTING  
PROBLEM  
SOLUTION  
COMPRESSOR DOES NOT RUN  
Contactor Open  
1. Power off.  
1. Restore power.  
2. Fuses blown in field power circuit.  
3. No control power.  
2. After finding cause and correcting, replace with correct size fuse.  
3. Check control transformer primary connections and circuit breaker.  
4. Check thermostat setting.  
4. Thermostat circuit open.  
5. Safety device lockout circuit active.  
6. Low-pressure switch open.  
5. Reset lockout circuit.  
6. Check for refrigerant undercharge, obstruction of indoor airflow.  
Make sure liquid line solenoid valve(s) is open.  
7. High-pressure switch open.  
7. Check for refrigerant overcharge, obstruction of outdoor airflow, air  
in system. Be sure outdoor fans are operating correctly.  
8. Compressor overtemperature switch open.  
9. Loose electrical connections.  
10. Compressor stuck.  
8. Check for open condition. Allow for reset. Replace if defective.  
9. Tighten all connections.  
10. See compressor service literature.  
Contactor Closed  
1. Compressor leads loose.  
2. Motor windings open.  
1. Check connections.  
2. See compressor service literature.  
3. Single phasing.  
3. Check for blown fuse. Check for loose connection at compressor  
terminal.  
COMPRESSOR STOPS ON HIGH-PRESSURE SWITCH  
Outdoor Fan On  
1. High-pressure switch faulty.  
2. Reversed fan rotation.  
3. Airflow restricted.  
1. Replace switch.  
2. Confirm rotation, correct if necessary.  
3. Remove obstruction.  
4. Air recirculating.  
4. Clear airflow area.  
5. Noncondensables in system.  
6. Refrigerant overcharge.  
7. Line voltage incorrect.  
8. Refrigerant system restrictions.  
Outdoor Fan Off  
5. Recover refrigerant and recharge as required.  
6. Recover refrigerant as required.  
7. Consult power company.  
8. Check or replace filter drier, expansion valve, etc.  
1. Fan slips on shaft.  
1. Tighten fan hub setscrews.  
2. Check power and capacitor.  
3. Replace bearings.  
2. Motor not running.  
3. Motor bearings stuck.  
4. Motor overload open.  
5. Motor burned out.  
4. Check overload rating. Check for fan blade obstruction.  
5. Replace motor.  
23  
TROUBLESHOOTING (cont)  
PROBLEM  
SOLUTION  
COMPRESSOR CYCLES ON LOW-PRESSURE SWITCH  
Indoor-Air Fan Running  
1. Liquid line solenoid valve(s) fails to open.  
1. Check liquid line solenoid valve(s) for proper operation. Replace if  
necessary.  
2. Filter drier plugged.  
3. Expansion valve power head defective.  
4. Low refrigerant charge.  
Airflow Restricted  
2. Replace filter drier.  
3. Replace power head.  
4. Add charge. Check low-pressure switch setting.  
1. Coil iced up.  
1. Check refrigerant charge.  
2. Clean coil fins.  
2. Coil dirty.  
3. Air filters dirty.  
3. Clean or replace filters.  
4. Check damper operation and position.  
4. Dampers closed.  
Indoor-Air Fan Stopped  
1. Electrical connections loose.  
2. Fan relay defective.  
3. Motor overload open.  
4. Motor defective.  
1. Tighten all connections.  
2. Replace relay.  
3. Power supply.  
4. Replace motor.  
5. Fan belt broken or slipping.  
5. Replace or tighten belt.  
COMPRESSOR RUNNING BUT COOLING INSUFFICIENT  
Suction Pressure Low  
1. Refrigerant charge low.  
2. Head pressure low.  
1. Add refrigerant.  
2. Check refrigerant charge. Check outdoor-air fan thermostat settings.  
3. Clean or replace filters.  
3. Air filters dirty.  
4. Expansion valve power head defective.  
5. Indoor coil partially iced.  
6. Indoor airflow restricted.  
Suction Pressure High  
4. Replace power head.  
5. Check low-pressure setting.  
6. Remove obstruction.  
1. Unloaders not functioning  
2. Heat load excessive.  
1. Check unloader adjustments. Check unloader setting.  
2. Check for open doors or windows in vicinity of fan coil.  
UNIT OPERATES TOO LONG OR CONTINUOUSLY  
1. Low refrigerant charge.  
1. Add refrigerant.  
2. Control contacts fused.  
2. Replace control.  
3. Air in system.  
3. Purge and evacuate system.  
4. Clean or replace.  
4. Partially plugged expansion valve or filter drier.  
SYSTEM IS NOISY  
1. Piping vibration.  
1. Support piping as required.  
2. Compressor noisy.  
2. Replace compressor if bearings are worn.  
COMPRESSOR LOSES OIL  
1. Leak in system.  
1. Repair leak.  
2. Crankcase heaters not energized during shutdown.  
3. Improper interconnecting piping design.  
2. Check wiring and relays. Check heater and replace if defective.  
3. Check piping for oil return. Replace if necessary.  
FROSTED SUCTION LINE  
Expansion valve admitting excess refrigerant.  
Adjust expansion valve.  
HOT LIQUID LINE  
1. Shortage of refrigerant due to leak.  
1. Repair leak and recharge.  
2. Adjust expansion valve.  
2. Expansion valve opens too wide.  
FROSTED LIQUID LINE  
1. Restricted filter drier.  
1. Remove restriction or replace.  
2. Replace valve.  
2. Liquid line solenoid valve partially closed.  
24  
• Do not install a suction-line filter drier in liquid-line.  
• POE oils absorb moisture rapidly. Do not expose oil to  
atmosphere.  
• POE oils may cause damage to certain plastics and  
roofing materials.  
APPENDIX  
AIR CONDITIONER AND HEAT PUMP WITH  
PURON® QUICK REFERENCE GUIDE  
®
• Puron (R-410A) refrigerant operates at 50 percent to  
70 percent higher pressures than R-22. Be sure that  
servicing equipment and replacement components are  
• Wrap all filter driers and service valves with wet cloth  
when brazing.  
• A factory approved, liquid-line filter drier is required on  
every unit.  
®
designed to operate with Puron .  
®
• Puron refrigerant cylinders are rose colored.  
• Recovery cylinder service pressure rating must be 400  
• Do not use an R-22 TXV.  
psig, DOT 4BA400 or DOT BW400.  
• If indoor unit is equipped with a TXV, it must be  
®
®
• Puron  
systems should be charged with liquid  
changed to a Puron TXV.  
refrigerant. Use a commercial type metering device in  
the manifold hose when charging into suction line with  
compressor operating.  
• Never open system to atmosphere while it is under a  
vacuum.  
• When system must be opened for service, recover  
refrigerant, break vacuum with dry nitrogen before  
opening system.  
• Manifold sets should be 700 psig high side and 180 psig  
low side with 550 psig low-side retard.  
• Use hoses with 700 psig service pressure rating.  
• Always replace filter drier after opening system for  
service.  
• Leak detectors should be designed to detect HFC  
refirgerant.  
®
• Do not vent Puron into the atmosphere.  
®
• Puron , as with other HFCs, is only compatible with  
• Do not use capillary tube coils.  
POE oils.  
• Observe all warnings, cautions, and bold text.  
Vacuum pumps will not remove moisture from oil.  
• Use only factory specified liquid-line filter driers with  
rated working pressures greater than 600 psig.  
®
• All Puron heat pumps must have indoor TXV.  
®
• Do not leave Puron suction line driers in place for  
more than 72 hours.  
25  
Copyright 2009 Carrier Corp • 7310 W. Morris St. • Indianapolis, IN 46231  
Printed in U.S.A.  
Edition Date: 03/09  
Catalog No: 38AU-01SI  
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.  
Replaces: NEW  
26  
III. START UP  
START-UP CHECKLIST  
I. PRELIMINARY INFORMATION  
OUTDOOR: MODEL NO.  
SERIAL NO.  
SERIAL NO.  
INDOOR: AIR HANDLER MANUFACTURER  
MODEL NO.  
ADDITIONAL ACCESSORIES  
II. PRE-START-UP  
OUTDOOR UNIT  
IS THERE ANY SHIPPING DAMAGE?  
IF SO, WHERE:  
(Y/N)  
WILL THIS DAMAGE PREVENT UNIT START-UP?  
(Y/N)  
CHECK POWER SUPPLY. DOES IT AGREE WITH UNIT?  
(Y/N)  
HAS THE GROUND WIRE BEEN CONNECTED?  
(Y/N)  
HAS THE CIRCUIT PROTECTION BEEN SIZED AND INSTALLED PROPERLY?  
ARE THE POWER WIRES TO THE UNIT SIZED AND INSTALLED PROPERLY?  
(Y/N)  
(Y/N)  
CONTROLS  
ARE THERMOSTAT AND INDOOR FAN CONTROL WIRING CONNECTIONS MADE AND CHECKED?  
(Y/N)  
ARE ALL WIRING TERMINALS (including main power supply) TIGHT?  
HAS CRANKCASE HEATER BEEN ENERGIZED FOR 24 HOURS?  
(Y/N)  
(Y/N)  
INDOOR UNIT  
HAS WATER BEEN PLACED IN DRAIN PAN TO CONFIRM PROPER DRAINAGE?  
ARE PROPER AIR FILTERS IN PLACE? (Y/N)  
HAVE FAN AND MOTOR PULLEYS BEEN CHECKED FOR PROPER ALIGNMENT?  
(Y/N)  
(Y/N)  
DO THE FAN BELTS HAVE PROPER TENSION?  
(Y/N)  
HAS CORRECT FAN ROTATION BEEN CONFIRMED?  
(Y/N)  
PIPING  
ARE LIQUID LINE SOLENOID VALVES LOCATED AT THE INDOOR COILS AS REQUIRED?  
(Y/N)  
HAVE LEAK CHECKS BEEN MADE AT COMPRESSOR, OUTDOOR AND INDOOR COILS,  
TXVs (Thermostatic Expansion Valves), SOLENOID VALVES, FILTER DRIERS, AND FUSIBLE PLUGS  
WITH A LEAK DETECTOR?  
(Y/N)  
LOCATE, REPAIR, AND REPORT ANY LEAKS.  
HAVE LIQUID LINE SERVICE VALVES BEEN OPENED?  
HAVE SUCTION SERVICE VALVES BEEN OPENED?  
(Y/N)  
(Y/N)  
CHECK VOLTAGE IMBALANCE  
LINE-TO-LINE VOLTS:  
(AB + AC + BC)/3 = AVERAGE VOLTAGE =  
MAXIMUM DEVIATION FROM AVERAGE VOLTAGE =  
AB  
V
AC  
V
BC  
V
V
V
VOLTAGE IMBALANCE = 100 X (MAX DEVIATION)/(AVERAGE VOLTAGE) =  
IF OVER 2% VOLTAGE IMBALANCE, DO NOT ATTEMPT TO START SYSTEM!  
CALL LOCAL POWER COMPANY FOR ASSISTANCE.  
CL-1  
CHECK INDOOR UNIT FAN SPEED AND RECORD.  
CHECK OUTDOOR UNIT FAN SPEED AND RECORD.  
AFTER AT LEAST 10 MINUTES RUNNING TIME, RECORD THE FOLLOWING MEASUREMENTS:  
SUCTION PRESSURE  
SUCTION LINE TEMP  
LIQUID PRESSURE  
LIQUID LINE TEMP  
ENTERING OUTDOOR UNIT AIR TEMP  
LEAVING OUTDOOR UNIT AIR TEMP  
INDOOR UNIT ENTERING-AIR DB (dry bulb) TEMP  
INDOOR UNIT ENTERING-AIR WB (wet bulb) TEMP  
INDOOR UNIT LEAVING-AIR DB TEMP  
INDOOR UNIT LEAVING-AIR WB TEMP  
COMPRESSOR AMPS (L1/L2/L3)  
/
/
NOTES:  
Copyright 2009 Carrier Corp • 7310 W. Morris St. • Indianapolis, IN 46231  
Printed in U.S.A.  
Edition Date: 03/09  
Catalog No: 38AU-01SI  
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.  
Pg CL-2  
Replaces: NEW  

Campbell Hausfeld MP5143 User Manual
Carrier 50GL A User Manual
Carrier AIR COOLED CONDENSING UNITS 38AE User Manual
Carrier KH_123P User Manual
Energizer Automobile Accessories Pro 4 User Manual
Epson Stylus Photo RX620 User Manual
Friedrich Air Conditioner SM24 SL 22 User Manual
Fujitsu Air Conditioner Room Air Conditioner Multi Split Type 3 rooms User Manual
HP Hewlett Packard CB532A User Manual
HP Hewlett Packard OFFICEJET 4500 User Manual