Carrier Gas Heater 48EJ User Manual

48EJ,EK,EW,EY024-048  
Single Package Rooftop Units  
Electric Cooling/Gas Heating  
Installation, Start-Up and  
Service Instructions  
CONTENTS  
Page  
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1  
1. Improper installation, adjustment, alteration, serv-  
ice, or maintenance can cause property damage, per-  
sonal injury, or loss of life. Refer to the User’s  
Information Manual provided with this unit for more  
details.  
2. Do not store or use gasoline or other flammable va-  
pors and liquids in the vicinity of this or any other  
appliance.  
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31  
Step 1 — Provide Unit Support . . . . . . . . . . . . . . . 1  
• ROOF CURB  
• ALTERNATE UNIT SUPPORT  
Step 2 — Rig and Place Unit . . . . . . . . . . . . . . . . . . 2  
• POSITIONING  
• ROOF MOUNT  
What to do if you smell gas:  
Step 3 — Field Fabricate Ductwork . . . . . . . . . . . . 2  
Step 4 — Install Flue Hood . . . . . . . . . . . . . . . . . . 12  
Step 5 — Trap Condensate Drain . . . . . . . . . . . . 13  
Step 6 — Install Gas Piping . . . . . . . . . . . . . . . . . . 13  
Step 7 — Controls Options . . . . . . . . . . . . . . . . . . 13  
• CONSTANT VOLUME APPLICATIONS  
VARIABLE AIR VOLUME (VAV) APPLICATIONS  
Step 8 — Make Electrical Connections . . . . . . . 16  
• POWER WIRING  
1. DO NOT try to light any appliance.  
2. DO NOT touch any electrical switch, or use any phone  
in your building.  
3. IMMEDIATELY call your gas supplier from a neigh-  
bor’s phone. Follow the gas supplier’s instructions.  
4. If you cannot reach your gas supplier, call the fire  
department.  
• FIELD POWER SUPPLY  
• FIELD CONTROL WIRING  
Step 9 — Make Outdoor-Air Inlet  
Disconnect gas piping from unit when pressure testing  
at pressure greater than 0.5 psig. Pressures greater than  
0.5 psig will cause gas valve damage resulting in haz-  
ardous condition. If gas valve is subjected to pressure  
greater than 0.5 psig, it must be replaced before use. When  
pressure testing field-supplied gas piping at pressures of  
0.5 psig or less, a unit connected to such piping must be  
isolated by closing the manual gas valve(s).  
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24  
• ECONOMIZER  
• ECONOMIZER SETTINGS  
Step 10 — Position Power Exhaust/Barometric  
Relief Hood . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29  
Step 11 — Install All Accessories . . . . . . . . . . . . 30  
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-44  
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44-55  
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 56-61  
START-UP CHECKLIST . . . . . . . . . . . . . . . . CL-1,CL-2  
INSTALLATION  
Step 1 — Provide Unit Support  
SAFETY CONSIDERATIONS  
1. All panels must be in place when rigging.  
Installation and servicing of air-conditioning equipment  
can be hazardous due to system pressure and electrical com-  
ponents. Only trained and qualified service personnel should  
install, repair, or service air-conditioning equipment.  
Untrained personnel can perform the basic maintenance  
functions of cleaning coils and filters and replacing filters.  
All other operations should be performed by trained service  
personnel. When working on air-conditioning equipment, ob-  
serve precautions in the literature, tags and labels attached  
to the unit, and other safety precautions that may apply.  
2. Unit is not designed for handling by fork truck.  
ROOF CURB — Assemble or install accessory roof curb in  
accordance with instructions shipped with this accessory. See  
Fig. 1 and 2. Install insulation, cant strips, roofing, and counter  
flashing as shown. Ductwork can be installed to roof curb  
before unit is set in place. Curb should be level. This is nec-  
essary to permit unit drain to function properly. Unit level-  
ing tolerance is shown in Fig. 1 and 2. Refer to Accessory  
Roof Curb Installation Instructions for additional informa-  
tion as required. When accessory roof curb is used, unit may  
be installed on class A, B, or C roof covering material.  
Follow all safety codes. Wear safety glasses and work gloves.  
Use quenching cloth for unbrazing operations. Have fire ex-  
tinguishers available for all brazing operations.  
IMPORTANT: The gasketing of the unit to the roof  
curb is critical for a watertight seal. Install gasket with  
the roof curb as shown in Fig. 1 and 2. Improperly  
applied gasket can also result in air leaks and poor unit  
performance.  
Before performing service or maintenance operations on  
unit, turn off main power switch to unit. Electrical shock  
could cause personal injury.  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
Book 1  
PC 111  
Catalog No. 564-962  
Printed in U.S.A.  
Form 48E-5SI  
Pg 1  
8-97  
Replaces: 48E-3SI  
Tab 1a  
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NOTES:  
UNIT LEVELING TOLERANCES DIMENSIONS*  
(Degrees and Inches)  
1. All roof curb parts are to be 16 ga galvanized steel.  
2. Dimensions are in inches.  
3. To prevent standing water in the drain pan of the indoor  
section and the heat exchangers, unit can only be pitched  
as shown.  
A
B
Deg.  
in.  
Deg.  
in.  
1.0  
2.9  
.50  
.75  
*From edge of unit to horizontal.  
Fig. 1 — Roof Curb (Sizes 024-034)  
3
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NOTES:  
UNIT LEVELING TOLERANCES DIMENSIONS*  
(Degrees and Inches)  
1. All roof curb parts are to be 16 ga galvanized steel.  
2. Dimensions are in inches.  
3. To prevent standing water in the drain pan of the indoor  
section and the heat exchangers, unit can only be pitched  
as shown.  
A
B
Deg.  
in.  
Deg.  
in.  
1.0  
2.9  
.50  
.75  
*From edge of unit to horizontal.  
Fig. 2 — Roof Curb (Sizes 038-048)  
4
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VFD — Variable Frequency Drive  
NOTES:  
1. Weights include economizer (STD).  
2.  
Center of gravity.  
3. Do not locate adjacent units with flue dis-  
charge facing economizer inlet. Minimum clear-  
ances to be:  
Adjacent Units: 15Ј-0Љ  
Top of Units: No overhang  
Condenser Coil: 4Ј-0Љ  
Economizer Side: 6Ј-0Љ  
Gas Heat Side: 4Ј-0Љ  
Filter Access Side: 10Ј-0Љ (For Removal of  
Evaporator Coil)  
4. For smaller service and operational clear-  
ances, contact Carrier Application Engineer-  
ing department.  
5. Bottom ducts designed to be attached to ac-  
cessory roof curb. If unit is mounted on dun-  
nage, it is recommended the ducts be  
supported by cross braces as done on ac-  
cessory roof curb.  
6. Dimensions are in inches.  
OPERATING  
WEIGHT  
A
B
CORNER WEIGHT (lb)  
UNIT  
SIZE  
lb  
ft-in.  
ft-in.  
1
2
3
4
48EJ,EKD024  
48EJE024  
4176  
4256  
4262  
4342  
4262  
4342  
4262  
4342  
6- 038 3-638  
6- 1516 3-61116 917 973 1218 1148  
5- 958 3-8  
899 899 1232 1232  
5-1018 3-8516 929 916 1240 1257  
5- 958 3-8  
899 899 1232 1232  
5-1018 3-8516 929 916 1240 1257  
5- 958 3-8  
899 899 1232 1232  
5-1018 3-8516 929 916 1240 1257  
879 954 1220 1124  
48EJ,EKD028  
48EJE028  
48EJ,EKD030  
48EJE030  
48EJ,EKD034  
48EJE034  
Fig. 3 — Base Unit Dimensions, 48EJ,EK024-034  
5
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VFD — Variable Frequency Drive  
OPERATING  
WEIGHT  
A
B
CORNER WEIGHT (lb)  
UNIT  
SIZE  
NOTES:  
1. Weights include economizer (STD).  
lb  
ft-in.  
ft-in.  
1
2
3
4
2.  
Center of gravity.  
48EJ,EKD038  
48EJE038  
4442  
4602  
4668  
4828  
4955  
5115  
7- 81116 3-1078  
7-1018 3-11316 1080 934 1200 1388  
7- 5516 3-1078  
1033 906 1275 1455  
7- 61316 3-11316 1094 945 1293 1496  
7- 31116 3-1012  
1068 953 1384 1550  
7- 5316 3-101316 1129 994 1401 1592  
1021 894 1180 1347  
3. Do not locate adjacent units with flue discharge facing econo-  
mizer inlet. Minimum clearances to be:  
Adjacent Units: 15Ј-0Љ  
48EJ,EKD044  
48EJE044  
Top of Units: No overhang  
Condenser Coil: 4Ј-0Љ  
48EJ,EKD048  
48EJE048  
Economizer Side: 6Ј-0Љ  
Gas Heat Side: 4Ј-0Љ  
Filter Access Side: 10Ј-0Љ (For Removal of Evaporator Coil)  
4. For smaller service and operational clearances, contact  
Carrier Application Engineering department.  
5. Bottom ducts designed to be attached to accessory roof curb.  
If unit is mounted on dunnage, it is recommended the ducts be  
supported by cross braces as done on accessory roof curb.  
6. Dimensions are in inches.  
Fig. 4 — Base Unit Dimensions, 48EJ,EK038-048  
6
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VFD — Variable Frequency Drive  
OPERATING  
WEIGHT  
A
B
CORNER WEIGHT (lb)  
UNIT  
SIZE  
NOTES:  
1. Weights include economizer (STD).  
lb  
ft-in.  
6- 038  
6- 1516  
5- 958  
5-1018  
5- 958  
5-1018  
5- 958  
5-1018  
ft-in.  
3-638  
3-61116  
3-8  
1
2
3
4
48EW,EYD024  
48EWE024  
4176  
4256  
4262  
4342  
4262  
4342  
4262  
4342  
879  
917  
899  
929  
899  
929  
899  
929  
954  
973  
899  
916  
899  
916  
899  
916  
1220  
1218  
1232  
1240  
1232  
1240  
1232  
1240  
1124  
1148  
1232  
1257  
1232  
1257  
1232  
1257  
2.  
Center of gravity.  
3. Do not locate adjacent units with flue discharge facing economizer inlet.  
Minimum clearances to be:  
48EW,EYD028  
48EWE028  
Adjacent Units: 15Ј-0Љ  
3-8516  
Top of Units: No overhang  
48EW,EYD030  
48EWE030  
3-8  
3-8516  
3-8  
Condenser Coil: 4Ј-0Љ  
Economizer Side: 6Ј-0Љ  
Gas Heat Side: 4Ј-0Љ  
48EW,EYD034  
48EWE034  
Filter Access Side: 10Ј-0Љ (For Removal of Evaporator Coil)  
4. For smaller service and operational clearances, contact Carrier  
Application Engineering department.  
3-8516  
5. Dimensions are in inches.  
6. For side-supply/return applications, a single return and supply ductwork  
connection is recommended for covering both return and both supply  
openings.  
Fig. 5 — Base Unit Dimensions, 48EW,EY024-034  
7
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VFD — Variable Frequency Drive  
OPERATING  
WEIGHT  
A
B
CORNER WEIGHT (lb)  
UNIT  
SIZE  
NOTES:  
1. Weights include economizer (STD).  
lb  
ft-in.  
7- 81116  
7-1018  
7- 5516  
7- 61316  
7- 31116  
7- 5316  
ft-in.  
3-1078  
3-11316  
3-1078  
3-11316  
3-1012  
3-101316  
1
2
3
4
48EW,EYD038  
48EWE038  
4442  
4602  
4668  
4828  
4955  
5115  
1021  
1080  
1033  
1094  
1068  
1129  
894  
934  
906  
945  
953  
994  
1180  
1200  
1275  
1293  
1384  
1401  
1347  
1388  
1455  
1496  
1550  
1592  
2.  
Center of gravity.  
3. Do not locate adjacent units with flue discharge facing economizer  
inlet. Minimum clearances to be:  
48EW,EYD044  
48EWE044  
Adjacent Units: 15Ј-0Љ  
Top of Units: No overhang  
48EW,EYD048  
48EWE048  
Condenser Coil: 4Ј-0Љ  
Economizer Side: 6Ј-0Љ  
Gas Heat Side: 4Ј-0Љ  
Filter Access Side: 10Ј-0Љ (For Removal of Evaporator Coil)  
4. For smaller service and operational clearances, contact Carrier  
Application Engineering department.  
5. Dimensions are in inches.  
6. For side-supply/return applications, a single return and supply duct-  
work connection is recommended for covering both return and both  
supply openings.  
Fig. 6 — Base Unit Dimensions, 48EW,EY038-048  
8
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WEIGHT  
lb kg  
48EJ,EK,EW,EYD024 4176 1894  
A
B
C
UNIT  
in.  
mm  
in.  
mm  
in.  
mm  
72.4 1839 42.4 1072  
73.3 1862 42.7 1085  
48EJ,EWE024  
4256 1930  
48EJ,EK,EW,EYD028  
48EJ,EK,EW,EYD030 4262 1933  
48EJ,EK,EW,EYD034  
69.6 1768 44.0 1118  
70.1 1781 44.3 1125  
87.68 2227  
48EJ,EWE028  
48EJ,EWE030  
48EJ,EWE034  
4342 1969  
48EJ,EK,EW,EYD038 4442 2015  
48EJ,EWE038 4602 2087  
48EJ,EK,EW,EYD044 4668 2117  
48EJ,EWE044 4828 2190  
48EJ,EK,EW,EYD048 4955 2248  
48EJ,EWE048 5115 2320  
92.7 2355 46.9 1191  
94.1 2390 47.2 1199  
89.3 2268 46.9 1191  
90.8 2306 47.2 1199  
87.7 2228 46.5 1181  
89.2 2266 46.8 1189  
150  
3810  
NOTICE TO RIGGERS:  
ALL PANELS MUST BE IN PLACE  
WHEN RIGGING.  
NOTE: Rig with four cables and spread with two  
92 in. (2337 mm) spreader bars. Maintain a dis-  
tance of 74 in. (1880 mm) from top of unit to  
eyehook.  
NOTE:  
Add 32 lb (14.5 kg) for domestic crating.  
Add 312 lb (142 kg) for export crating (024-034 units).  
Add 346 lb (157 kg) for export crating (038-048 units).  
Add 250 lb (113 kg) for power exhaust.  
Add 220 lb (100 kg) for copper condenser coil (024-034 units).  
Add 285 lb (129 kg) for copper condenser coil (038,044 units).  
Add 380 lb (172 kg) for copper condenser coil (048 unit).  
Fig. 7 — Rigging Label  
9
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Table 1 — Physical Data  
UNIT 48EJ,EK,EW,EY  
024D/E  
028D/E  
030D/E  
034D/E  
NOMINAL CAPACITY (tons)  
20  
25  
27  
30  
OPERATING WEIGHT (lb)*  
Unit  
Al/Al† (Lo Heat/Hi Heat)  
Al/Cu† (Lo Heat/Hi Heat)  
Roof Curb (14-in. curb)  
4176/4256  
4396/4476  
365  
4262/4342  
4482/4562  
365  
4262/4342  
4482/4562  
365  
4262/4342  
4482/4562  
365  
COMPRESSOR  
Type Ckt 1  
06D328  
06D818  
2
06D328  
06D328  
2
06D537  
06D328  
2
06D537  
06D537  
2
Ckt 2  
Number of Refrigerant Circuits  
Oil (oz) (Ckt 1, Ckt 2)  
115, 88  
115 ea.  
115 ea.  
115 ea.  
REFRIGERANT TYPE  
Operating Charge (lb-oz)  
Circuit 1**  
R-22  
25-0  
31-0  
25-0  
25-0  
25-0  
25-0  
25-0  
25-0  
Circuit 2  
3
CONDENSER COIL  
Quantity  
Rows...Fins/in.  
Total Face Area (sq ft)  
Cross-Hatched  
8Љ Copper Tubes, Aluminum Lanced, Aluminum Pre-Coated, or Copper Plate Fins  
1
1
1
1
4...15  
33.3  
4...15  
33.3  
4...15  
33.3  
4...15  
33.3  
CONDENSER FAN  
Nominal Cfm  
Quantity...Diameter (in.)  
Motor Hp (1075 Rpm)  
Propeller Type  
13,420  
2...30  
1
13,420  
2...30  
1
13,420  
2...30  
1
13,420  
2...30  
1
3
EVAPORATOR COIL  
Rows...Fins/in.  
Total Face Area (sq ft)  
Cross-Hatched  
8Љ Copper Tubes, Aluminum Plate Fins, Intertwined Circuits  
4...15  
31.7  
4...15  
31.7  
4...15  
31.7  
4...15  
31.7  
EVAPORATOR FAN  
Centrifugal Type  
Quantity...Size (in.)  
2...20x15  
Belt  
2...20x15  
Belt  
2...20x15  
Belt  
2...20x15  
Belt  
Type Drive  
Nominal Cfm  
8,000  
10††  
S215T  
S215T  
Ball  
10,000  
10††  
S215T  
S215T  
Ball  
11,000  
15††  
D254T  
S254T  
Ball  
12,000  
15††  
D254T  
S254T  
Ball  
Motor Hp  
5
15  
7.5  
15  
D254T  
S254T  
10  
S215T  
S215T  
20  
10  
20  
Motor Frame Size (Standard)  
(High Efficiency)  
S184T  
S184T  
D254T  
S254T  
S213T  
S213T  
S256T  
S256T  
S215T  
S215T  
S256T  
S256T  
Motor Bearing Type  
Maximum Allowable Rpm  
Motor Pulley Pitch Diameter  
Nominal Motor Shaft Diameter (in.)  
Fan Pulley Pitch Diameter (in.)  
Nominal Fan Shaft Diameter (in.)  
Belt, Quantity...Type  
1200  
4.4  
1200  
6.1  
1200  
4.9  
1200  
5.7  
4.8  
118  
12.4  
5.7  
158  
9.1  
5.4  
138  
12.4  
5.5  
158  
8.7  
4.4  
138  
9.4  
5.9  
158  
8.7  
4.4  
138  
9.0  
5.9  
158  
8.7  
138  
138  
158  
158  
8.6  
11.1  
8.1  
9.1  
11516  
11516  
11516  
11516  
1...BX59 2...BX51 2...5VX530 1...BX59 1...5VX590 2...5VX530 2...BX52 2...5VX500 2...5VX530 2...BX51 2...5VX530 2...5VX530  
Belt, Length (in.)  
Pulley Center Line Distance (in.)  
Factory Speed Setting (rpm)  
62  
54  
53  
62  
59  
15.6-18.4  
962  
53  
15.0-17.9 15.6-18.4  
1106 848  
55  
50  
53  
54  
15.6-18.4  
884  
53  
53  
16.0-18.7 15.6-18.4 15.0-17.9  
15.0-17.9  
15.0-17.9  
717  
924  
225  
1096  
773  
1059  
1187  
1096  
1187  
FURNACE SECTION  
Rollout Switch Cutout Temp (F)ሻ  
Burner Orifice Diameter  
(in. ...drill size)  
225  
225  
225  
Natural Gas  
Liquid Propane  
Std  
Alt  
.111...34  
.089...43  
.111...34  
.089...43  
.111...34  
.089...43  
.111...34  
.089...43  
Thermostat Heat Anticipator  
Setting (amps)  
Stage 1  
0.1  
0.1  
0.1  
0.1  
0.1  
0.1  
0.1  
0.1  
Stage 2  
Gas Input (Btuh)  
Stage 1 Low  
262,500  
394,000  
350,000  
525,000  
82  
262,500  
394,000  
350,000  
525,000  
82  
262,500  
394,000  
350,000  
525,000  
82  
262,500  
394,000  
350,000  
525,000  
82  
High  
Stage 2 Low  
High  
Efficiency (Steady State) (%)  
Temperature Rise Range  
Manifold Pressure (in. wg)  
15-45/35-65  
15-45/35-65  
15-45/35-65  
15-45/35-65  
Natural Gas  
Std  
Alt  
3.5  
3.5  
2
3.5  
3.5  
2
3.5  
3.5  
2
3.5  
3.5  
2
Liquid Propane  
Gas Valve Quantity  
Field Gas Connection Size  
(in.-FPT)  
1.5  
1.5  
1.5  
1.5  
HIGH-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto.)  
426  
320  
426  
320  
426  
320  
426  
320  
LOW-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto.)  
7
22  
7
22  
7
22  
7
22  
OUTDOOR-AIR FILTERS  
Quantity...Size (in.)  
8...16 × 25  
4...20 × 25  
RETURN-AIR FILTERS  
Quantity...Size (in.)  
10...20x24x2  
10...20x24x2  
10...20x24x2  
10...20x24x2  
POWER EXHAUST  
Motor, Quantity...Hp  
Fan, Diameter... Width (in.)  
Direct Drive, 3-Speed, Single-Phase Motor (Factory-Wired for High Speed) and Forward-Curved Fan  
4...1  
11...10  
4...1  
4...1  
4...1  
11...10  
11...10  
11...10  
NOTE: High heat is for 48EJ,EW only.  
LEGEND  
Al  
Aluminum  
Copper  
VFD WEIGHTS (lb)  
Cu  
VFD  
(Hp)  
208/230 v  
460 v  
22  
575 v  
60  
*Weight of unit does not include variable frequency drive (VFD) barometric relief, or power  
exhaust. If a VFD is installed, add the VFD weight in the table at right.  
†Evaporator coil fin material/condenser coil fin material.  
5
7.5  
10  
15  
20  
25  
30  
20  
51  
37  
64  
**Sizes 024-034: Circuit 1 uses the lower portion of condenser coil, Circuit 2 uses the upper  
portion. Sizes 038-048: Circuit 1 uses the left condenser coil, Circuit 2 the right. All units  
have intertwined evaporator coils.  
††Motor and drive shown will deliver approximately 2.5 in. wg net external static. See  
Table 2 for more information.  
51  
61  
64  
61  
63  
109  
109  
174  
180  
63  
111  
112  
118  
Rollout switch is manual reset.  
105  
172  
10  
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Table 1 — Physical Data (cont)  
UNIT 48EJ,EK,EW,EY  
038D/E  
044D/E  
048D/E  
NOMINAL CAPACITY (tons)  
35  
40  
45  
OPERATING WEIGHT (lb)*  
Unit  
Al/Al† (Lo Heat/Hi Heat)  
Al/Cu† (Lo Heat/Hi Heat)  
Roof Curb (14-in. curb)  
4442/4602  
4727/4887  
410  
4668/4828  
4953/5113  
410  
4955/5115  
5335/5495  
410  
COMPRESSOR  
Type Ckt 1  
06D537  
06D537  
2
06EA250  
06EA250  
2
06EA265  
06EA250  
2
Ckt 2  
Number of Refrigerant Circuits  
Oil (oz) (Ckt 1, Ckt 2)  
115 ea.  
224 ea.  
304, 224  
REFRIGERANT TYPE  
Operating Charge (lb-oz)  
Circuit 1**  
R-22  
34-0  
34-0  
35-0  
35-0  
41-0  
41-0  
Circuit 2  
3
CONDENSER COIL  
Quantity  
Rows...Fins/in.  
Total Face Area (sq ft)  
Cross-Hatched  
8Љ Copper Tubes, Aluminum Lanced, Aluminum Pre-Coated, or Copper Plate Fins  
2
2
1
1
3...15  
58.3  
3...15  
58.3  
4...15  
3...15  
66.7  
CONDENSER FAN  
Nominal Cfm  
Quantity...Diameter (in.)  
Motor Hp (1075 Rpm)  
Propeller Type  
27,064  
4...30  
1
27,064  
4...30  
1
27,064  
4...30  
1
3
EVAPORATOR COIL  
Rows...Fins/in.  
Total Face Area (sq ft)  
Cross-Hatched  
8Љ Copper Tubes, Aluminum Plate Fins, Intertwined Circuits  
3...15  
34.7  
3...15  
34.7  
4...15  
34.7  
EVAPORATOR FAN  
Centrifugal Type  
2...20x15  
Belt  
Quantity...Size (in.)  
2...20x15  
Belt  
2...20x15  
Belt  
Type Drive  
Nominal Cfm  
14,000  
15††  
D254T  
S254T  
Ball  
16,000  
18,000  
25††  
Motor Hp  
10  
20  
15  
20††  
S256T  
S256T  
Ball  
25  
20  
30  
Motor Frame Size (Standard)  
(High Efficiency)  
S215T  
S215T  
S256T  
S256T  
D254T  
S254T  
S284T  
S284T  
S256T  
S256T  
S284T  
S284T  
Ball  
S286T  
S286T  
Motor Bearing Type  
Maximum Allowable Rpm  
Motor Pulley Pitch Diameter  
Nominal Motor Shaft Diameter (in.)  
Fan Pulley Pitch Diameter (in.)  
Nominal Fan Shaft Diameter (in.)  
Belt, Quantity...Type  
1200  
5.3  
1200  
5.7  
1200  
6.1  
5.7  
158  
9.5  
5.3  
158  
9.5  
7.5  
178  
11.1  
6.3  
158  
11.1  
5.9  
7.5  
178  
11.1  
138  
13.7  
158  
158  
178  
9.5  
9.5  
12.5  
11516  
2...5VX530  
53  
11516  
2...5VX550  
55  
11516  
2...5VX630  
63  
1...5VX650  
65  
15.6-18.4  
779  
2...5VX550  
55  
2...5VX530  
53  
2...5VX590  
59  
14.6-17.6  
1182  
2...5VX570  
57  
15.0-17.9  
993  
2...5VX610  
59  
Belt, Length (in.)  
Pulley Center Line Distance (in.)  
Factory Speed Setting (rpm)  
15.0-17.9  
15.0-17.9  
14.6-17.6  
976  
225  
1050  
976  
1050  
225  
1134  
225  
1182  
FURNACE SECTION  
Rollout Switch Cutout Temp (F)ሻ  
Burner Orifice Diameter  
(in. ...drill size)  
Natural Gas  
Liquid Propane  
Std  
Alt  
.120...31  
.096...41  
.120...31  
.096...41  
.120...31  
.096...41  
Thermostat Heat Anticipator  
Setting (amps)  
Stage 1  
0.1  
0.1  
0.1  
0.1  
0.1  
0.1  
Stage 2  
Gas Input (Btuh)  
Stage 1 Low  
300,000  
600,000  
400,000  
800,000  
82  
300,000  
600,000  
400,000  
800,000  
82  
300,000  
600,000  
400,000  
800,000  
82  
High  
Stage 2 Low  
High  
Efficiency (Steady State) (%)  
Temperature Rise Range  
Manifold Pressure (in. wg)  
10-40/30-60  
10-40/30-60  
10-40/30-60  
Natural Gas  
Std  
Alt  
3.5  
3.5  
2
3.5  
3.5  
2
3.5  
3.5  
2
Liquid Propane  
Gas Valve Quantity  
Field Gas Connection Size (in.-FPT)  
1.5  
1.5  
1.5  
HIGH-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto.)  
426  
320  
426  
320  
426  
320  
LOW-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto.)  
7
22  
7
22  
7
22  
OUTDOOR-AIR FILTERS  
Quantity...Size (in.)  
8...16 × 25  
4...20 × 25  
RETURN-AIR FILTERS  
Quantity...Size (in.)  
10...20x24x2  
10...20x24x2  
10...20x24x2  
POWER EXHAUST  
Motor, Quantity...Hp  
Fan, Diameter... Width (in.)  
Direct Drive, 3-Speed, Single-Phase motor (Factory-Wired for High Speed) and Forward Curved Fan  
4...1  
4...1  
4...1  
11...10  
11...10  
11...10  
NOTE: High heat is for 48EJ,EW only.  
LEGEND  
Al  
Aluminum  
Copper  
VFD WEIGHTS (lb)  
Cu  
VFD  
(Hp)  
208/230 v  
460 v  
22  
575 v  
*Weight of unit does not include variable frequency drive (VFD) barometric relief, or power  
exhaust. If a VFD is installed, add the VFD weight in the table at right.  
†Evaporator coil fin material/condenser coil fin material.  
5
7.5  
10  
15  
20  
25  
30  
20  
51  
60  
64  
37  
**Sizes 024-034: Circuit 1 uses the lower portion of condenser coil, Circuit 2 uses the upper  
portion. Sizes 038-048: Circuit 1 uses the left condenser coil, Circuit 2 the right. All units  
have intertwined evaporator coils.  
††Motor and drive shown will deliver approximately 2.5 in. wg net external static. See  
Table 2 for more information.  
51  
61  
64  
61  
63  
109  
109  
174  
180  
63  
111  
112  
118  
Rollout switch is manual reset.  
105  
172  
11  
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Table 2 — Evaporator Fan Motor Data (Units with Starting Serial Numbers 4197 and Later)  
MOTOR  
SHEAVE  
PITCH  
DIAMETER  
(in.)  
FAN  
SHEAVE  
PITCH  
DIAMETER  
(in.)  
MOTOR  
FAN  
BELT  
TENSION  
(Lb at  
UNIT  
SIZE  
48E  
BUSHING  
DIAMETER  
(in.)  
BUSHING  
DIAMETER  
(in.)  
OUTSIDE  
BELT  
LENGTH  
MOTOR SHAFT  
SHAFT MOTOR  
SPEED SHEAVE  
(rpm)  
FAN  
SHEAVE  
BELT  
(QUANTITY)  
HP  
DIA.  
(in.)  
.24 in.)  
5
10  
15  
1.12  
1.38  
1.62  
717  
924  
BK55  
2BK50  
2B5V56  
4.8  
4.4  
5.7  
None-1.125 1B5V124  
12.4  
8.6  
B-1.9375  
B-1.9375  
B-1.9375  
BX59  
62  
54  
53  
5.10  
5.21  
6.00  
024  
028  
030  
034  
038  
044  
048  
None-1.375  
B-1.625  
2B5V86  
2B5V90  
(2) BX51  
(2) 5VX530  
1096  
9.1  
7.5  
10  
15  
1.38  
1.38  
1.62  
773  
962  
1106  
BK60H  
1B5V60  
2B5V54  
5.4  
6.1  
5.5  
H-1.375  
H-1.375  
B-1.625  
1B5V124  
1B5V110  
2B5V86  
12.4  
11.1  
8.7  
B-1.9375  
B-1.9375  
B-1.9375  
BX59  
5VX590  
(2) 5VX530  
62  
59  
53  
6.48  
7.37  
6.12  
10  
15  
20  
1.38  
1.62  
1.62  
848  
1059  
1187  
2BK50  
2B5V48  
2B5V58  
4.4  
4.9  
5.9  
None-1.375  
B-1.625  
B-1.625  
2B5V94  
2B5V80  
2B5V86  
9.4  
8.1  
8.7  
B-1.9375  
B-1.9375  
B-1.9375  
(2) BX52  
(2) 5VX500  
(2) 5VX530  
55  
50  
53  
5.27  
6.63  
7.31  
10  
15  
20  
1.38  
1.62  
1.62  
884  
1096  
1187  
2BK50  
2B5V56  
2B5V58  
4.4  
5.7  
5.9  
H-1.375  
B-1.625  
B-1.625  
2B5V90  
2B5V90  
2B5V86  
9.0  
9.1  
8.7  
B-1.9375  
B-1.9375  
B-1.9375  
(2) BX51  
(2) 5VX530  
(2) 5VX530  
54  
53  
53  
5.24  
6.00  
7.31  
10  
15  
20  
1.38  
1.62  
1.62  
779  
976  
1050  
1B5V60  
2B5V52  
2B5V56  
6.1  
5.3  
5.7  
None-1.375 1B5V136  
13.7  
9.5  
9.5  
B-1.9375  
B-1.9375  
B-1.9375  
5VX650  
(2) 5VX530  
(2) 5VX550  
65  
53  
55  
7.62  
6.37  
7.60  
B-1.625  
B-1.625  
2B5V94  
2B5V94  
15  
20  
25  
1.62  
1.62  
1.88  
976  
1050  
1182  
2B5V52  
2B5V56  
2B5V74  
5.3  
5.7  
7.5  
B-1.625  
B-1.625  
B-1.875  
2B5V94  
2B5V94  
2B5V110  
9.5  
9.5  
11.1  
B-1.9375  
B-1.9375  
B-1.9375  
(2) 5VX530  
(2) 5VX550  
(2) 5VX590  
53  
55  
59  
6.37  
7.60  
7.60  
20  
25  
30  
1.62  
1.88  
1.88  
993  
1134  
1182  
2B5V62  
2B5V80  
2B5V74  
6.3  
5.9  
7.5  
B-1.625  
B-1.875  
B-1.875  
2B5V110  
2B5V124  
2B5V110  
11.1  
12.5  
11.1  
B-1.9375  
B-1.9375  
B-1.9375  
(2) 5VX570  
(2) 5VX630  
(2) 5VX590  
57  
63  
59  
7.22  
7.36  
9.07  
NOTE: Motor shaft speed is 1750 rpm. The fan shaft diameter is 11516 inches.  
Step 4 — Install Flue Hood — Flue hood is shipped  
inside gas section of unit. To install, secure flue hood to ac-  
cess panel. See Fig. 10.  
NOTE: When properly installed, flue hood will line up with  
combustion fan housing. See Fig. 11.  
Fig. 8 — Air Distribution — Thru-the-Bottom  
Fig. 9 — Air Distribution — Thru-the-Side  
Fig. 10 — Flue Hood Location  
12  
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Step 5 — Trap Condensate Drain — See Fig. 3-6  
for drain location. Condensate drain is open to atmosphere  
and must be trapped. Install a trapped drain at the drain lo-  
cation. A trap at least 4-in. deep must be used. See Fig. 12.  
Trap must be installed to prevent freeze-up.  
Condensate pans are sloped so that water will completely  
drain from the condensate pan to comply with indoor air qual-  
ity guidelines. The condensate drain pan is fitted with a 1-in.  
FPT coupling.  
Step 6 — Install Gas Piping — Unit is equipped for  
use with natural gas. Installation must conform with local  
building codes or, in the absence of local codes, with the  
National Fuel Gas Code, ANSI Z223.1.  
1
Install manual gas shutoff valve with a 8-in. NPT pres-  
sure tap for test gage connection at unit. Field gas piping  
must include sediment trap and union. See Fig. 13. An  
Fig. 11 — Combustion Fan Housing Location  
1
8-in. NPT is also located on the gas manifold adjacent to  
the gas valve.  
Do not pressure test gas supply while connected to unit.  
Always disconnect union before servicing.  
IMPORTANT: Natural gas pressure at unit gas con-  
nection must not be less than 5 in. wg or greater than  
13.5 in. wg.  
Size gas-supply piping for 0.5-in. wg maximum pressure  
drop. Do not use supply pipe smaller than unit gas  
connection.  
Step 7 — Controls Options — The control options  
that the units can provide are based on the following param-  
eters: CV (constant volume) or VAV (variable air volume)  
operation; stand-alone unit with field-supplied sensors in-  
stalled (CV or VAV); as a system via Carrier Comfort Sys-  
tem (TEMP or VVT); optional electronic expansion board  
installed (CV or VAV); linked to the Carrier Comfort  
Network; and availability of a computer and software  
(ComfortWorks™ Building Supervisor, and Service Tool) or  
LID-2B accessory installed to access the base control board.  
See Table 3.  
Fig. 12 — Condensate Drain Trap Piping Details  
(Typical Roof Curb or Slab Mount Shown)  
NOTE: Access to the base control board allows unit occu-  
pancy schedules, unit timeclock, and various set points to be  
changed from their factory-defined default settings.  
All units are equipped with a supply air thermistor (SAT)  
located in the supply fan discharge and an outdoor air ther-  
mistor (OAT) located in the outdoor air hood. Variable air  
volume units are supplied with a return air thermistor (RAT)  
located on the return air damper support.  
CONSTANT VOLUME APPLICATIONS — The units, as  
shipped, are operable as stand-alone units, using either a stand-  
ard (mechanical or electronic) 2-stage heat, 2-stage cool ther-  
mostat, or with an electronic room sensor and a timeclock to  
establish unit start and stop times.  
With a standard thermostat (programmable is optional),  
heating and cooling operation is set by space temperature.  
With a space sensor and timeclock, the machine will op-  
erate at default values unless they are changed using appro-  
priate input devices. The space sensor senses space tempera-  
ture and may be equipped with a timed override feature, which  
allows unit operation during unoccupied periods.  
Fig. 13 — Field Gas Piping  
The space sensors may be used in multiples of 4 or 9 to  
achieve space temperature averaging. The use of a space sen-  
sor also allows the unit to be turned on and off from a re-  
mote signal.  
Features with Thermostat Control of Unit  
• two-stage heating  
• two-stage cooling  
• control of unit using Y1, Y2, W1, W2, and G thermostat  
inputs  
• control of the indoor fan  
• outdoor-air temperature/supply-air temperature  
monitoring  
• control of an outdoor air condenser fan based on outdoor-  
air temperature  
13  
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Table 3 — Controls Options and Configurations (Non-Thermostat Applications)  
UNIT CONFIGURATION  
DEFAULT COOLING  
DEFAULT HEATING  
Unoccupied Cooling — 90 F (SPT)  
Occupied Cooling — NA  
Unoccupied Heating — 55 F (SPT)  
Occupied Heating — NA  
CV or VAV Unit with SPT Sensor  
CV Unit with SPT Sensor and Remote  
Start/Stop Switch  
Unoccupied Cooling — 90 F (SPT)  
Occupied Cooling — 78 F (SPT)  
Unoccupied Heating — 55 F (SPT)  
Occupied Heating — 68 F (SPT)  
Unoccupied Cooling — 90 F (RAT)  
Occupied Cooling — 55 F (SAT)  
Unoccupied Heating — 55 F (RAT)  
Occupied Heating — 68 F (RAT)*  
VAV Unit Remote Start/Stop Switch Only  
VAV Unit with SPT Sensor and Remote  
Start/Stop Switch  
Unoccupied Cooling — 90 F (SPT)  
Occupied Cooling — 55 F (SAT)  
Unoccupied Heating — 55 F (SPT)  
Occupied Heating — 68 F (RAT)*  
LEGEND  
*With DIP Switch No. 5 configured to OPEN (Occupied Heat  
Enabled).  
CV  
Constant Volume  
Not Available  
Return-Air Temperature  
Supply-Air Temperature  
Space Temperature  
Variable Air Volume  
NA  
NOTE: Space temperature sensor and remote start/stop switch are  
field-supplied.  
RAT  
SAT  
SPT  
VAV  
• control of modulating economizer damper to provide free  
cooling when outdoor conditions are suitable, using  
supply-air temperature as a control point  
• control of the economizer damper and indoor fan to obtain  
unoccupied free cooling  
• ability to initiate timed override from T-55 or T-56 sensors  
for a timed period of 1 to 4 hours  
• ability to use multiple space temperature sensors to aver-  
age the space temperature  
• temperature compensated start to calculate early start times  
before occupancy  
• access to the Display, Maintenance, Configuration,  
Service, and Set Point data tables through network  
software  
When the unit is equipped with a field-supplied space  
temperature sensor and a remote contact closure (remote start/  
stop) on the base control board, the occupied default set points  
will monitor unit operation. The occupied default set points  
are 78 F cooling and 68 F heating. See Fig. 14 for remote  
start/stop wiring.  
• provide power exhaust output to an external power ex-  
haust controller  
• support a field test for field checkout  
• control of 2 stages of CV power exhaust  
• compressor Time Guard(power up, minimum off and on  
times)  
• compressor lockout during low supply-air temperature  
Additional features are provided by accessing the stand-  
ard unit control board via software with a computer. These  
features are:  
• electronic expansion board features (if installed)  
• control board diagnostics  
NOTE: For units with a field-supplied space temperature se-  
sor which have not had the base unit control board accessed  
via software to set an occupancy schedule, the remote start/  
stop closure will allow the unit to operate in the pre-  
configured occupied default set points (based on return-air  
temperature) of 78 F cooling and 68 F heating. Without this  
feature, the unit will control to the unoccupied default set  
points of 90 F cooling and 55 F heating.  
An electronic expansion board may be field-installed to  
provide the following features:  
• control of modulating economizer damper to maintain in-  
door air quality (IAQ) when outdoor conditions are  
suitable  
• ability to change supply air set point (economizer control)  
• ability to change high outdoor temperature lockout set point  
(economizer control)  
• ability to change power exhaust set points  
NOTE: A CV unit without a thermostat requires a field-  
supplied sensor for operation.  
Features with Sensor Control of Unit (Stand-Alone Appli-  
cations — Unit control is limited to CV unoccupied default  
set points, 90 F for cooling, 55 F for heating. There are  
2 sensor options available:  
T-55 sensor will monitor room temperature and provide  
unoccupied override capability (1 hour)  
T-56 sensor will monitor room temperature, provide un-  
occupied override capability (1 hour), and provide a tem-  
perature offset of 5° F.  
NOTE: The IAQ sensor must be set for current output  
(4 to 20 mA), not voltage output. Ensure the jumper on  
the sensor is in the upper position. See Fig. 15.  
• provide discrete inputs for fan status, filter status, field-  
applied status, and demand limit  
• provide an output for the external alarm light indicator  
• provide power exhaust fire outputs for direct control of  
modulated power exhaust stages during fire or smoke modes  
• control of smoke control modes including evacuation, smoke  
purge, pressurization, and fire shutdown (modulating power  
exhaust required)  
When the unit is connected to the CCN (Carrier Comfort  
Network), the following expansion board features can be  
utilized:  
Standard features are:  
• support of remote occupied/unoccupied input to start and  
stop the unit  
• cooling capacity control of 3 stages using economizer and  
2 compressors to maintain space temperature to an occu-  
pied or unoccupied set point  
• enable heating or cooling during unoccupied periods as  
required to maintain space temperature within the unoc-  
cupied set points  
• adjustment of space temperature set points of ±5° F when  
using a T-56 sensor  
Additional features with sensor control of unit (with com-  
puter access) are:  
• perform Demand Limit functions based on CCN loadshed  
commands or the state of the discrete input  
• alarm monitoring of all key parameters  
• CCN protocol  
• provides CCN IAQ participation  
• 365 day timeclock with backup (supports minute, hour, day  
of week, date, month, and year)  
• daylight savings time function  
• occupancy control with 8 periods for unit operation  
• holiday table containing up to 18 holiday schedules  
See Carrier TEMP or VVT(Variable Volume and Tem-  
perature) literature for complete TEMP (single zone) or VVT  
(multi-zone) application information.  
14  
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VARIABLE AIR VOLUME (VAV) APPLICATIONS  
Features with Stand-Alone Applications — The units, as  
shipped, are operable as stand-alone units with the addition  
of a timeclock to establish unit start and stop times.  
Heating and cooling in both on and off modes is con-  
trolled to default values by the base unit control. Set points  
may be changed with appropriate input devices.  
REMOTE  
START/STOP  
SWITCH  
(FIELD-SUPPLIED)  
R
Y1  
Y2  
W1  
W2  
G
The control has an on-board occupancy schedule which  
can be set using an input device and eliminates the need for  
an external timeclock.  
During both the on and off periods, cooling operation is  
controlled to the supply air setting and heating is controlled  
to the return air setting (or to the optional space temperature  
sensor). During the on period, the supply fan runs continu-  
ously. During the off period, the supply fan will be activated  
if the return air sensor is outside of the set points and will  
run log enough to accurately sample the space temperature.  
The supply fan will then continue to run until any heating or  
cooling load is satisfied, at which point it will turn off.  
The use of a space sensor will allow for supply air reset  
to conserve energy and maintain comfort. If equipped with  
an override feature, the sensor will allow operation during  
the off period for a fixed length of time.  
C
X
CONTROL  
BOX  
LEGEND  
Field Supplied Wiring  
Fig. 14 — Field Control Remote Start/Stop  
Base unit control supports a Heat Interlock Relay (field  
supplied) to fully open the VAV terminal devices during heat-  
ing operation.  
JUMPER CONNECTION  
FOR VOLTAGE OUTPUT  
Standard features of a VAV unit with a remote start/stop  
switch are:  
• control board diagnostics  
• control of an outdoor condenser fan based upon outdoor  
air temperature  
• control of modulating economizer to provide free cooling  
when outdoor conditions are suitable, using supply-air tem-  
perature as a set point  
• support of remote occupied/unoccupied input to start or  
stop the unit  
JUMPER CONNECTION  
FOR CURRENT OUTPUT  
• provide power exhaust output to an external power ex-  
haust controller  
• support supply-air temperature reset to offset supply air  
set point  
• support a field test for field check out  
• support linkage to DAV systems  
• cooling capacity control of up to 6 stages plus economizer  
with compressors and unloaders to maintain supply air tem-  
perature set point during occupied periods  
• control of one stage of heat to maintain return-air tem-  
perature at heating set point during occupied periods  
• provide a variable frequency drive high voltage relay out-  
put to enable VFD  
Fig. 15 — Indoor Air Quality Sensor Configuration  
• control of heat interlock relay  
• compressor Time Guard override (power up, minimum off  
and on times)  
With the addition of a remote start/stop switch heating or  
cooling is enabled during unoccupied periods as required to  
maintain space temperature to within unoccupied set points.  
Additional features may be provided with Electronic  
Access to Unit Control Board. These features are:  
• additional control board diagnostics  
Features with Sensor Control of Unit (Network Applica-  
tions) — The base control board provides, as standard, a con-  
nection for use with a Carrier VVT system and can also be  
integrated into a Carrier Comfort Network.  
When the unit is accessed via a PC equipped with Com-  
fortWorks™, Building Supervisor, or Service Tool software,  
or accessory LID-2B, the following features can be  
accessed:  
• electronic expansion board features (if installed)  
• control of the economizer damper and indoor fan to obtain  
unoccupied free cooling  
• on-board timeclock can be programmed  
• occupancy schedules can be programmed  
• unit set points can be changed  
• 365-day timeclock with backup (supports minute, hour, day,  
month, and year)  
• alarms can be monitored  
This access is available on the base control board via a  
RJ-11 phone jack or a 3-wire connection to the communi-  
cation bus. See Fig. 16. The timeclock has a 10-hour mini-  
mum back-up time to provide for unit power off for servic-  
ing unit or during unexpected power outages. For complete  
Carrier Comfort System (CCS) or Carrier Comfort Network  
(CCN) features and benefits, refer to the product literature.  
• holiday table containing up to 18 holiday schedules  
• occupancy control with 8 periods for unit operation  
• support a set of display, maintenance, configuration, serv-  
ice, and set point data tables for interface with Building  
Supervisor, ComfortWorks, or Service Tool software soft-  
ware or accessory LID-2B  
15  
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When a VAV unit with a space temperature sensor is ac-  
cessed via a computer, the following additional features are  
available:  
• ability to initiate timed override from T-55 sensors  
• temperature compensated start to calculate early start time  
before occupancy  
• provide space temperature reset to reset the supply air set  
point upward when the temperature falls below the occu-  
pied cooling set point  
An electronic expansion board may be field-installed to  
provide the following features:  
Step 8 — Make Electrical Connections  
POWER WIRING — Units are factory wired for the voltage  
shown on the unit nameplate.  
When installing units, provide a disconnect per NEC  
(National Electrical Code) of adequate size (MOCP [maxi-  
mum overcurrent protection] of unit is on the informative  
plate). 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. 17 for power wiring con-  
nections to the unit power terminal block and equipment ground.  
The main power terminal block is suitable for use with  
aluminum or copper wire. See Fig. 17. Units have circuit  
breakers for compressors, fan motors, and control circuit. If  
required by local codes, provide an additional disconnect switch.  
Whenever external electrical sources are used, unit must be  
electrically grounded in accordance with local codes, or in  
absence of local codes, with NEC, ANSI C1-latest year.  
• fan status  
• filter status  
• field-applied status  
• demand limiting  
• IAQ Sensor  
• OAQ Sensor  
• alarm light  
• fire unit shutdown  
• fire pressurization  
• fire evacuation  
• fire smoke purge  
When the unit is connected to the CCN (Carrier Comfort  
Network), the following expansion board features can be  
utilized:  
All field wiring must comply with NEC and local code  
requirements.  
FIELD POWER SUPPLY — Unit is factory wired for volt-  
age shown on unit nameplate. See Table 4 for electrical data.  
Field wiring can be brought into the unit from bottom  
(through basepan and roof curb) or through side of unit (cor-  
ner post next to control box).  
• CCN IAQ (indoor air quality) participation  
• CCN OAQ (outdoor air quality) participation  
• CCN demand limit participation  
A 312-in. NPT coupling for field power wiring and a  
3
4-in. NPT coupling for 24-v control wiring are provided in  
basepan. In the side post, there are two 212-in. (024-034) or  
3-in. (038-048) knockouts for the field power wiring. See  
Fig. 3-6. If control wiring is to be brought in through the  
• modulated power exhaust override  
• ability to use multiple space temperature sensors (mul-  
tiples of 4 and 9 only) to average space temperature (DAV  
only)  
7
side of unit, a 8-in. diameter hole is provided in the con-  
denser side post next to the control box.  
Aeld-supplied T-55 space temperature sensor can be added  
to monitor room temperature and provide unoccupied over-  
ride capability (1 hour).  
If disconnect box is mounted to corner post, be careful  
not to drill any screws into the condenser coil.  
Routing Through Bottom of Unit — If wiring is brought in  
through bottom of unit, use field-supplied watertight conduit  
to run power wiring from basepan out through bottom  
312-in. hole to the disconnect box and back into unit to the  
main control box.  
Use strain relief going into control box through 212-in.  
diameter hole provided. After wires are in unit control box,  
connect to power terminal block (see Power Wiring section  
above).  
Low-voltage wiring must be run in watertight conduit from  
the basepan to control box and through 78-in. diameter hole  
provided in bottom of unit control box. Field-supplied strain  
relief must be used going into the box. After wiring is in  
control box, make connections to proper terminals on ter-  
minal blocks (see Field Control Wiring section on page 21).  
When the unit is equipped with a field-supplied space tem-  
perature sensor and a remote contact closure (remote start/  
stop) the occupied default set points will monitor unit op-  
eration. The occupied default set points are 55 F (supply air)  
cooling and 68 F (return air temperature) heating. See  
Fig. 14 for remote start/stop wiring.  
NOTE: For units without a space temperature sensor and which  
have not had the base unit control board accessed via soft-  
ware to set an occupancy schedule, the remote start/stop clo-  
sure will allow the unit to operate in the pre-configured oc-  
cupied default set points of 55 F (supply-air temperature)  
cooling and 68 F (return-air temperature) heating. Without  
an occupancy schedule, the unit will control to the unoccu-  
pied default set points of 90 F (return air) cooling and 55 F  
(return air) heating.  
Features with NetworkApplications — The base control board  
provides, as standard, a connection for use with a Carrier  
Comfort System and can also be integrated into a Carrier  
Comfort Network. When the unit is accessed via a PC equipped  
with ComfortWorks™, Building Supervisor, or Service Tool  
software or LID-2B accessory, the following features can be  
accessed:  
Install conduit connector in unit basepan as shown in  
Fig. 3-6. Route power and ground lines through connector to  
terminal connections in unit control box as shown on unit  
wiring diagram and Fig. 17.  
Routing Through Side of Unit — Route power wiring in field-  
supplied watertight conduit into unit through 212-in. hole.  
See Fig. 17.  
Use field-supplied strain relief going into control box through  
212-in. diameter hole provided. After wires are in unit con-  
trol box, connect to power terminal block (see Power Wiring  
section on this page).  
• on-board timeclock can be programmed  
• occupancy schedules can be programmed  
• unit set points can be changed  
• alarms can be monitored  
This access is available on the base control board via a  
RJ-11 phone jack or a 3-wire connection to the communi-  
cation bus. See Fig. 16. The internal timeclock has a 10-hour  
minimum back-up time to provide for unit power off for ser-  
vicing unit or during unexpected power outages. For com-  
plete Carrier Comfort System (CCS) or Carrier Comfort  
Network (CCN) features and benefits, refer to the product  
literature.  
Bring low-voltage control wiring through factory-drilled  
7
8-in. diameter hole in condenser side post. Use strain relief  
going into 78-in. diameter hole in bottom of unit control box.  
After wiring is in control box, make connection to proper  
terminals on terminal blocks (see Field Control Wiring sec-  
tion on page 21).  
16  
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LEGEND  
*Where X is the unit control software version number.  
CCN  
COM  
D
LED  
N.C.  
Carrier Comfort Network  
Common  
N.O.  
R
SIO  
SW  
T
Normally Open  
Relay  
Diode  
Serial Input/Output  
Switch  
Light-Emitting Diode  
Normally Closed  
Terminal  
Fig. 16 — Control Board Diagram  
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Table 4 — Electrical Data  
COMPRESSOR  
No. 1 No. 2  
VOLTAGE  
RANGE  
POWER COMBUSTION  
EXHAUST FAN MOTOR  
OFM  
IFM  
POWER SUPPLY  
MCA MOCP*  
UNIT  
SIZE  
NOMNAL  
VOLTAGE  
FLA  
(ea)  
48E (3 Ph 60 Hz)  
Min Max RLA LRA RLA LRA Qty Hp  
Hp FLA FLA LRA  
FLA  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
101.8/100.3 125/125  
125.4/123.9 150/150  
115.9/113.1 150/150  
139.5/136.7 175/175  
131.3/127.1 150/150  
154.9/150.7 175/175  
16.7/  
15.2  
5
23.6 41.6  
30.8/  
28.0  
208/230  
187 254 39.1 228 25.6 160  
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
1
1
1
5.3 10  
23.6 41.6  
46.2/  
42.0  
15  
5
23.6 41.6  
49.4  
62.0  
55.8  
68.4  
62.8  
75.4  
40.5  
53.1  
45.4  
58.0  
51.4  
64.0  
60  
80  
70  
80  
80  
90  
50  
60  
60  
70  
60  
80  
7.6  
12.6 23.6  
024  
028  
030  
460  
575  
414 508 19.9 114 11.5  
80  
64  
2.7 10 14.0  
15 21.0  
12.6 23.6  
12.6 23.6  
5
6.1  
12.6 23.6  
518 632 16.0  
91  
9.6  
2.4 10 11.0  
15 17.0  
12.6 23.6  
12.6 23.6  
122.8/120.6 150/150  
146.4/144.2 175/175  
129.4/126.6 150/150  
153.0/150.2 175/175  
144.8/140.6 175/175  
168.4/164.2 200/200  
24.2/  
7.5  
22.0  
23.6 41.6  
30.8/  
5.3 10  
208/230  
187 254 39.1 228 39.1 228  
28.0  
23.6 41.6  
46.2/  
15  
42.0  
23.6 41.6  
61.2  
73.8  
64.2  
76.8  
71.2  
83.8  
49.8  
62.4  
51.8  
64.4  
57.8  
70.4  
80  
90  
80  
90  
90  
100  
60  
70  
60  
80  
70  
80  
7.5 11.0  
2.7 10 14.0  
15 21.0  
12.6 23.6  
460  
414 508 19.9 114 19.9 114  
12.6 23.6  
12.6 23.6  
7.5  
9.0  
12.6 23.6  
575  
518 632 16.0  
91 16.0  
91  
2.4 10 11.0  
15 17.0  
12.6 23.6  
12.6 23.6  
151.9/149.1 200/200  
175.5/172.7 225/225  
167.3/163.1 225/225  
190.9/186.7 225/225  
180.5/175.1 225/225  
204.1/198.7 250/250  
30.8/  
10  
28.0  
23.6 41.6  
46.2/  
5.3 15  
208/230  
187 254 57.1 266 39.1 228  
42.0  
23.6 41.6  
59.4/  
20  
54.0  
23.6 41.6  
71.3  
83.9  
78.3  
90.9  
84.3  
96.9  
57.4  
70.0  
63.4  
76.0  
68.4  
81.0  
90  
100  
100  
110  
100  
110  
70  
10 14.0  
2.7 15 21.0  
20 27.0  
12.6 23.6  
460  
414 508 25.6 120 19.9 114  
12.6 23.6  
12.6 23.6  
10 11.0  
12.6 23.6  
90  
80  
575  
518 632 20.5  
96 16.0  
91  
2.4 15 17.0  
20 22.0  
12.6 23.6  
90  
80  
12.6 23.6  
100  
See Legend and Notes on page 19.  
18  
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Table 4 — Electrical Data (cont)  
COMPRESSOR  
No. 1 No. 2  
VOLTAGE  
RANGE  
POWER COMBUSTION  
EXHAUST FAN MOTOR  
OFM  
IFM  
POWER SUPPLY  
MCA MOCP*  
UNIT NOMINAL  
SIZE  
VOLTAGE  
FLA  
(ea)  
48E (3 Ph 60 Hz)  
Min Max RLA LRA RLA LRA Qty Hp  
Hp FLA FLA LRA  
FLA  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
169.9/167.1 225/200  
193.5/190.7 250/225  
185.3/181.1 225/225  
208.9/204.7 250/250  
198.5/193.1 250/250  
222.1/216.7 275/250  
30.8/  
28.0  
10  
23.6 41.6  
46.2/  
42.0  
208/230  
187 254 57.1 266 57.1 266  
2
2
2
4
4
4
1
1
1
1
1
1
5.3 15  
20  
23.6 41.6  
59.4/  
54.0  
23.6 41.6  
77.0  
89.6  
84.0  
96.6  
90.0  
102.6  
61.9  
74.5  
67.9  
80.5  
72.9  
85.5  
100  
110  
100  
110  
110  
125  
80  
10 14.0  
2.7 15 21.0  
20 27.0  
12.6 23.6  
034  
460  
575  
414 508 25.6 120 25.6 120  
12.6 23.6  
12.6 23.6  
10 11.0  
12.6 23.6  
90  
80  
518 632 20.5  
96 20.5  
96  
2.4 15 17.0  
20 22.0  
12.6 23.6  
100  
90  
12.6 23.6  
100  
180.5/177.7 225/225  
204.1/201.3 250/250  
195.9/191.7 250/225  
219.5/215.3 275/250  
209.1/203.7 250/250  
232.7/227.3 275/275  
30.8/  
10  
28.0  
23.6 41.6  
46.2/  
5.3 15  
208/230  
187 254 57.1 266 57.1 266  
414 508 25.6 120 25.6 120  
518 632 20.5 96 20.5 96  
42.0  
23.6 41.6  
59.4/  
20  
54.0  
23.6 41.6  
82.4  
95.0  
89.4  
102.0  
95.4  
108.0  
66.7  
79.3  
72.7  
85.3  
77.7  
90.3  
100  
110  
110  
125  
110  
125  
80  
10 14.0  
2.7 15 21.0  
20 27.0  
12.6 23.6  
038  
460  
12.6 23.6  
12.6 23.6  
10 11.0  
12.6 23.6  
90  
90  
575  
2.4 15 17.0  
20 22.0  
12.6 23.6  
100  
90  
12.6 23.6  
110  
LEGEND  
EXAMPLE: Supply voltage is 460-3-60.  
AB = 452 v  
BC = 464 v  
AC = 455 v  
FLA  
Full Load Amps  
HACR  
Heating, Air Conditioning and  
Refrigeration  
IFM  
Indoor (Evaporator) Fan Motor  
Locked Rotor Amps  
Minimum Circuit Amps  
Maximum Overcurrent Protection  
National Electrical Code  
Outdoor (Condenser) Fan Motor  
Rated Load Amps  
452 + 464 + 455  
LRA  
MCA  
MOCP  
NEC  
OFM  
RLA  
Average Voltage =  
=
3
1371  
3
or  
= 457  
*Fuse or HACR circuit breaker.  
Determine maximum deviation from average voltage.  
(AB) 457 − 452 = 5 v  
(BC) 464 − 457 = 7 v  
(AC) 457 − 455 = 2 v  
NOTES:  
Maximum deviation is 7 v.  
1. In compliance with NEC requirements for multimotor and combi-  
nation load equipment (refer to NEC Articles 430 and 440), the  
overcurrent protective device for the unit shall be fuse or HACR  
breaker. Canadian units may be fuse or circuit breaker.  
2. Unbalanced 3-Phase Supply Voltage  
Determine percent voltage imbalance.  
7
% Voltage Imbalance = 100 x  
457  
Never operate a motor where a phase imbalance in supply volt-  
age is greater than 2%. Use the following formula to determine  
the percent voltage imbalance.  
= 1.53%  
This amount of phase imbalance is satisfactory as it is below the  
maximum allowable 2%.  
% Voltage Imbalance  
IMPORTANT: If the supply voltage phase imbalance is more  
than 2%, contact your local electric utility company  
immediately.  
max voltage deviation from average voltage  
= 100 x  
average voltage  
19  
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Table 4 — Electrical Data (cont)  
COMPRESSOR  
No. 1 No. 2  
VOLTAGE  
RANGE  
POWER COMBUSTION  
EXHAUST FAN MOTOR  
OFM  
IFM  
POWER SUPPLY  
MCA MOCP*  
UNIT NOMINAL  
SIZE  
VOLTAGE  
FLA  
(ea)  
48E (3 Ph 60 Hz)  
Min Max RLA LRA RLA LRA Qty Hp  
Hp FLA FLA LRA  
FLA  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.96  
0.96  
0.96  
0.96  
0.96  
0.96  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
0.50  
223.1/218.9 275/275  
246.7/242.5 300/300  
236.3/230.9 300/300  
259.9/254.5 300/300  
251.7/244.9 300/300  
275.3/268.5 300/300  
46.2/  
42.0  
15  
23.6 41.6  
59.4/  
54.0  
208/230  
187 254 69.2 345 69.2 345  
414 508 28.8 173 28.8 173  
518 632 26.7 120 26.7 120  
187 254 82.1 446 69.2 345  
414 508 42.3 223 28.8 173  
518 632 34.6 164 26.7 120  
4
4
4
4
4
4
1
1
1
1
1
1
5.3 20  
25  
23.6 41.6  
74.8/  
68.0  
23.6 41.6  
96.6  
109.2  
102.6  
115.2  
109.6  
122.2  
86.7  
125  
125  
125  
125  
125  
150  
110  
125  
110  
125  
110  
125  
15 21.0  
2.7 20 27.0  
25 34.0  
12.6 23.6  
044  
460  
575  
12.6 23.6  
12.6 23.6  
15 17.0  
12.6 23.6  
99.3  
91.7  
2.4 20 22.0  
25 27.0  
12.6 23.6  
104.3  
96.7  
12.6 23.6  
109.3  
252.4/247.0 300/300  
276.0/270.6 300/300  
267.8/261.0 300/300  
291.4/284.6 300/300  
281.0/273.0 300/300  
304.6/296.6 350/300  
59.4/  
20  
54.0  
23.6 41.6  
74.8/  
5.3 25  
208/230  
68.0  
23.6 41.6  
88.0/  
30  
80.0  
23.6 41.6  
119.5  
132.1  
126.5  
139.1  
132.5  
145.1  
101.6  
114.2  
106.6  
119.2  
111.6  
124.2  
150  
150  
150  
175  
150  
175  
125  
125  
125  
150  
125  
150  
20 27.0  
2.7 25 34.0  
30 40.0  
12.6 23.6  
048  
460  
12.6 23.6  
12.6 23.6  
20 22.0  
12.6 23.6  
575  
2.4 25 27.0  
30 32.0  
12.6 23.6  
12.6 23.6  
LEGEND  
EXAMPLE: Supply voltage is 460-3-60.  
FLA  
Full Load Amps  
AB = 452 v  
BC = 464 v  
AC = 455 v  
HACR  
Heating, Air Conditioning and  
Refrigeration  
IFM  
Indoor (Evaporator) Fan Motor  
Locked Rotor Amps  
Minimum Circuit Amps  
Maximum Overcurrent Protection  
National Electrical Code  
Outdoor (Condenser) Fan Motor  
Rated Load Amps  
452 + 464 + 455  
LRA  
MCA  
MOCP  
NEC  
OFM  
RLA  
Average Voltage =  
=
3
1371  
3
or  
= 457  
*Fuse or HACR circuit breaker.  
Determine maximum deviation from average voltage.  
(AB) 457 − 452 = 5 v  
(BC) 464 − 457 = 7 v  
(AC) 457 − 455 = 2 v  
NOTES:  
Maximum deviation is 7 v.  
1. In compliance with NEC requirements for multimotor and combi-  
nation load equipment (refer to NEC Articles 430 and 440), the  
overcurrent protective device for the unit shall be fuse or HACR  
breaker. Canadian units may be fuse or circuit breaker.  
2. Unbalanced 3-Phase Supply Voltage  
Determine percent voltage imbalance.  
7
% Voltage Imbalance = 100 x  
457  
Never operate a motor where a phase imbalance in supply volt-  
age is greater than 2%. Use the following formula to determine  
the percent voltage imbalance.  
= 1.53%  
This amount of phase imbalance is satisfactory as it is below the  
maximum allowable 2%.  
% Voltage Imbalance  
IMPORTANT: If the supply voltage phase imbalance is more than  
2%, contact your local electric utility company immediately.  
max voltage deviation from average voltage  
= 100 x  
average voltage  
20  
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Sensor Wiring (CV or VAV) — The temperature sensor is  
wired into the unit control board. See Fig. 21.  
IMPORTANT: THE VAV (variable air volume) units  
use variable frequency drives, which generate, use and  
can radiate radio frequency energy. If units are not in-  
stalled and used in accordance with these instructions,  
they may cause radio interference. They have been tested  
and found to comply with limits of a Class A com-  
puting device as defined by FCC (Federal Communi-  
cations Commission) regulations, Subpart J of Part 15,  
which are designed to provide reasonable protection  
against such interference when operated in a commer-  
cial environment.  
The unit is controlled with a T-55 or T-56 (CV only) zone  
sensor. Terminal TH (T-56) or T1 (T-55) on the sensor is  
connected to T1 of the base module board. Terminal COM  
(T-56) or T2 (T-55) on the sensor is connected to T2 on the  
base module board. If a T-56 set point override sensor is used,  
the override connection SW on the sensor is connected to T3  
on the base module board.  
If more than sensor is being used and averaged, sensors  
must be wired in multiples of 4 or 9. See Fig. 22.  
Heat Interlock Relay VAV units require a field-supplied  
heat interlock relay (HIR) to drive the air terminal wide open  
when in heat mode. Heat Interlock relay part number is  
HN61KK041.  
The unit must be electrically grounded in accordance  
with local codes and NEC ANSI/NFPA 70 (National Fire  
Protection Association).  
Affix crankcase heater sticker (located in the installers packet)  
to unit disconnect switch.  
Voltage to compressor terminals during compressor op-  
eration must be within the voltage range indicated on the  
unit nameplate. On 3-phase units, phases must be balanced  
within 2%. Contact local power company for correction of  
improper voltage or phase imbalance. Unit failure due to op-  
eration of unit on improper line voltage or with excessive  
phase imbalance constitutes abuse and may cause damage to  
unit electrical components.  
On 208/230-v units, transformer no. 1 is wired for 230-v.  
If 208/230-v unit is to be run with 208-v power supply, the  
transformer must be rewired as follows:  
1. Remove cap from red (208 v) wire.  
2. Remove cap from spliced orange (230 v) wire. Discon-  
nect orange wire from black unit power wire.  
LEGEND  
GND  
NEC  
TB  
Ground  
National Electrical Code  
Terminal Block  
NOTE: Maximum wire size for TB1 is 500 MCM.  
3. Cap orange wire.  
4. Splice red wire and black unit power wire. Cap wires.  
Fig. 17 — Field Power Wiring Connections  
IMPORTANT: BE CERTAIN UNUSED WIRES  
ARE CAPPED. Failure to do so may damage the  
transformers.  
FIELD CONTROL WIRING — The unit can use either a  
Carrier-approved thermostat or a CCN (Carrier Comfort  
Network) compatible temperature sensor. Thermostats are used  
on CV (constant volume) units only. Control box diagrams  
are shown in Fig. 18 and 19.  
Thermostat Wiring (CV Only) — Install a Carrier-approved  
accessory thermostat assembly (per current price pages) ac-  
cording to the installation instructions included with the ac-  
cessory or these instructions. Locate the thermostat on a solid  
interior wall in the conditioned space to sense the average  
temperature.  
Route the thermostat cable or equivalent single leads of  
colored wire from the subbase terminals to the low-voltage  
connection as shown on unit label wiring diagram and in  
Fig. 20.  
NOTE: For wire runs up to 50 ft, use no. 18 AWG  
(American Wire Gage) insulated wire (35 C minimum). For  
50 to 75 ft, use no. 16 AWG insulated wire (35 C minimum).  
For over 75 ft, use no. 14 AWG insulated wire (35 C mini-  
mum). All wire larger than no. 18 AWG cannot be directly  
connected at the thermostat and will require a junction box  
and splice at the thermostat.  
LEGEND  
C
Compressor/Contactor  
Circuit Breaker  
Dual In-Line Package  
Fuse  
IF  
Indoor Fan  
CB  
DIP  
FU  
HR  
OF  
Outdoor Fan  
PEC  
TB  
TRAN  
Power Exhaust Controller  
Terminal Block  
Transformer  
Heater Relay  
Set heat anticipators to 0.1 for all voltages.  
Fig. 18 — Control Box Diagram (Sizes 024-034)  
21  
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LEGEND  
C
Contactor/Compressor  
Circuit Breaker  
Dual In-Line Package  
Fuse  
IF  
Indoor Fan  
CB  
DIP  
FU  
HR  
OF  
Outdoor Fan  
PEC  
TB  
TRAN  
Power Exhaust Controller  
Terminal Block  
Transformer  
Heater Relay  
Fig. 19 — Control Box Diagram (Sizes 038-048)  
NOTE: Sensor part numbers are as follows:  
T-55 CEC0121448-01  
T-56 CEC0121503-01  
Fig. 21 — Field Control Temperature Sensor Wiring  
(CV or VAV Units)  
Fig. 20 — Field Control Thermostat Wiring  
22  
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SPACE TEMPERATURE AVERAGING — 4 SENSOR APPLICATION  
SPACE TEMPERATURE AVERAGING — 9 SENSOR APPLICATION  
Fig. 22 — Space Temperature Averaging Wiring  
signal pins must be wired to signal ground pins. Wiring con-  
Remote Field Control — A switch closure across terminals  
R and W1 on TB-3 will initiate the Occupied mode. This  
can be done manually as well as through a field-supplied  
timeclock.  
nections for CCN should be made at the 3-pin plug (CCN  
located at the base board). Consult CCN literature for fur-  
ther information.  
Conductors and drain wire must be 20 AWG minimum  
stranded, tinned copper. Individual conductors must be in-  
sulated with PVC, PVC/nylon, vinyl, Teflon, or polyethyl-  
ene. An aluminum/polyester 100% foil shield and an outer  
jacket of PVC, PVC/nylon, chrome vinyl, or Teflon with a  
minimum operating temperature range of −20 C to 60 C  
(−4 F to 140 F) is required. Table 5 lists cables that meet the  
requirements.  
Service Tool, Building Supervisor, and ComfortWorks™  
Software — Access to the control board can be achieved through  
the terminal marked CCN via a 3-wire bus.  
IMPORTANT: The default bus address is 0. The de-  
fault element number is 1. Refer to CCN literature to  
change the default values, if needed.  
Carrier Comfort Network Interface — The 48E units can be  
connected to the CCN. The communication bus wiring is sup-  
plied and installed in the field. Wiring consists of shielded,  
3-conductor cable with drain wire.  
The system elements are connected to the communication  
bus in a daisy chain arrangement. The positive pin of each  
system element communication connector must be wired to  
the positive pins of the system element on either side of it,  
the negative pins must be wired to the negative pins, and the  
Table 5 — CCN Connection Approved Shielded Cables  
MANUFACTURER  
Alpha  
CABLE PART NO.  
2413 or 5463  
A22503  
American  
Belden  
8772  
Columbia  
02525  
23  
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2. Assemble hood sides, top, and cross member with gas-  
keted screws provided. See Fig. 24.  
3. Attach 10 green speed clips (provided) to hood top.  
4. Apply black seal strip (provided) to mounting flanges of  
hood sides being sure to cover mounting holes. See  
Fig. 25.  
IMPORTANT: When connecting the CCN communi-  
cation bus to a system element, use a color coding sys-  
tem for the entire network to simplify installation and  
checkout. See Table 6.  
NOTE: Each hood assembly has a slotted side that should  
be adjacent to the other hood when mounted to the unit.  
Table 6 — Color Code Recommendations  
SIGNAL  
TYPE  
Positive (+)  
Ground  
CCN BUS CONDUCTOR  
INSULATION COLOR  
CCN PLUG  
PIN NO.  
5. Apply black seal strip (provided) to hood top mounting  
flange. Seal strip of hood top mounting flange must press  
tightly against seal strip of hood side mounting flanges.  
See Fig. 26.  
6. Add gray foam strip (provided in package) to cross mem-  
bers on bottom tray. See Fig. 27.  
7. Place gray foam strip (provided) on inside of slotted hood  
side between filter and cross member opposite the mount-  
ing end. See Fig. 28.  
8. Attach gray foam strip (provided) to block-off baffle on  
outer face of flange. See Fig. 29.  
9. Remove the screws on each end and along top of damper  
assembly of unit. Remove top 2 screws on each side of  
filter panel under damper assembly. Set hood assembly  
in place and attach to unit using these screws.  
10. Attach accessory enthalpy bracket on hood side furthest  
from control box end. Locate bracket on inside upper  
right-hand corner of economizer hood using hood mount-  
ing holes. Mount outdoor-air thermistor to enthalpy bracket  
(if purchased). Attach and wire enthalpy assembly. Place  
quick connects on enthalpy wires.  
11. Remove screws along bottom of damper assembly. Lo-  
cate and mount blockoff baffle using these screws.  
12. Assemble 2 filter tracks side-by-side with the as-  
sembled ends together.  
13. Attach mounting angle (without tabs) to the assembled  
end of the filter track. See Fig. 30.  
14. Attach 6 green speed clips (provided) to mounting angles.  
Engagement section of clip faces inside of rack.  
15. Attach remaining mounting angle (with tabs) to other  
end of the filter track with no. 10 screws provided. See  
Fig. 31.  
16. Place filter track assembly in bottom of hood by placing  
tabbed end into slotted side (with tab on bottom) and  
attaching opposite end to hood with speed clips and gas-  
keted screws provided. Tabs can be hand bent after they  
have been inserted into the side.  
RED  
WHITE  
BLACK  
1
2
3
Negative (−)  
NOTE: If a cable with a different color scheme is selected,  
a similar color code should be adopted for the entire  
network.  
At each system element, the shields of the communica-  
tion bus cables must be tied together. If the communication  
bus is entirely within one building, the resulting continuous  
shield must be connected to a ground at one point only. If  
the communication bus cable exits from one building and  
enters another, the shields must be connected to grounds at  
the lightning suppressor in each building where the cable  
enters or exits the building (one point per building only).  
To connect the unit to the network:  
1. Turn off power to the control box.  
2. Cut the CCN wire and strip the ends of the red (+), white  
(ground), and black (−) conductors. (If a different net-  
work color scheme is used, substitute appropriate  
colors.)  
3. Remove the 3-pin male plug from the base module in the  
main control box, and connect the wires as follows:  
a. Insert and secure the red (+) wire to terminal 1 of the  
3-pin plug.  
b. Insert and secure the white (ground) wire to  
terminal 2 of the 3-pin plug.  
c. Insert and secure the black (−) wire to terminal 3 of  
the 3-pin plug.  
4. Insert the plug into the existing 3-pin mating connector  
on the base module in the main control box.  
Step 9 — Make Outdoor-Air Inlet Adjustments  
ECONOMIZER  
NOTE: If accessory power exhaust or barometric relief pack-  
ages are being added to the unit, install power exhaust or  
barometric relief before installing economizer hoods.  
NOTE: The filter track assembly end with screws should  
face away from the other hood when mounted on the  
unit.  
NOTE: Tabs from both filter tracks will be in the same  
space. After one filter track has been inserted into hood  
side, bend the tabs so they will not interfere with in-  
stallation of the second hood.  
Economizer Hood Assembly — The economizer hood is  
shipped in a package secured to the outside of the unit and  
must be field-assembled. There are 2 hoods on every unit.  
The 48EW/EY units are side supply and side return. The re-  
turn duct limits access to economizer filters from below.  
Filter tracks (mounting angle without tabs) must be installed  
correctly to allow access to economizer filters from each side.  
Perform the following procedure to assemble the econo-  
mizer hood:  
17. Attach black seal strip (provided) to filter cover. Seal  
strip should be applied to the center of the large flange  
making sure to cover holes. See Fig. 32.  
18. Slide two 20 x 25-in. filters into cross members of hood  
assembly. Attach filter cover over filters with screws and  
speed clips provided.  
NOTE: Before assembly of the economizer hood, check along  
the outer edges of the economizer assembly for any seal strip  
protruding past the flanges. Trim the excess seal strip so that  
it is flush with the economizer assembly flanges.  
Minimum Damper Position Setting — Setting of the out-  
door air damper position is performed in conjunction with a  
shortened version of the field run test. This is performed by  
first opening DIP (Dual In-line Package) switch no. 4 then  
no. 6. See Fig. 18 and 19 and Direct Digital Controls DIP  
Switch Configuration section on page 33.  
1. Apply black seal strip (provided in package) to outside  
top-edge of hood sides. Wrap seal strip over edge to cover  
top flange (4 hood sides). Make sure seal strip covers  
screw holes. Allow strip to overhang 18-in. past the end  
opposite the mounting flange. See Fig. 23.  
24  
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TOP  
FLANGE  
BLACK  
SEAL  
STRIP  
HOOD SIDE  
MOUNTING  
FLANGE  
HOOD SIDE  
Fig. 23 — Adding Seal Strip to Top of Hood Sides  
Fig. 25 — Adding Seal Strip to Mounting Flange of  
Hood Sides  
HOOD TOP  
HOOD SIDE  
Fig. 26 — Adding Seal Strip to Hood Top  
Mounting Flange  
NOTE: Left side economizer hood has mounting angle without tabs  
and filter track assembled end on the opposite side.  
GRAY FOAM STRIP  
Fig. 24 — Economizer Hood Assembly  
(Right Side Economizer Hood Shown)  
CROSS MEMBER  
Fig. 27 — Adding Foam Strip to Cross Member  
25  
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The outdoor-air damper closes. The control allows 90 sec-  
onds for the damper to close in case it is in the full open  
position. Next, the indoor-fan contactor will energize. The  
outdoor-air damper will remain at 0% for 30 seconds. It will  
then move to the 10% position for another 30 seconds. This  
will be repeated at every 10% increment for 30 seconds until  
the damper reaches 100% open. Close DIP switch no. 4 dur-  
ing the 30 seconds immediately after the desired outdoor air  
minimum damper position. The 30-second time period is to  
allow time where DIP switch no. 4 can be closed. The de-  
fault value of the minimum outdoor air damper position is  
20%. If the desired minimum position is 30%, allows the  
damper position to go to 10% for 30 seconds, then 20% for  
30 seconds, and when it reaches 30% close DIP switch  
no. 4 during the 30-second period following the 30%  
position.  
HOOD SIDE  
(SLOTTED)  
HOOD  
TOP  
The minimum outdoor air damper position is now set. Close  
DIP switch no. 6.  
ECONOMIZER SETTINGS  
Accessory Enthalpy Control (Fig. 33) — The control  
(HH57AC077) is mounted in the economizer hood. See  
Fig. 24. The enthalpy setting adjustment is on the enthalpy  
control. For maximum benefit of outdoor air, set enthalpy  
control to A. See Fig. 34 and 35.  
Fig. 28 — Adding Foam Strip to Hood Side  
Enthalpy Control Installation — The outdoor air enthalpy con-  
trol is installed on the inside panel of the outdoor air hood.  
The enthalpy control should be mounted when the outdoor  
air hoods are assembled. To install the control, perform the  
following procedure:  
BLOCKOFF BAFFLE  
1. Turn off all power. Ensure disconnect is locked out.  
2. Remove the economizer inlet filters from the bottom of  
the right hand economizer hood. See Fig. 24. See Fig. 36  
for economizer details.  
GRAY FOAM STRIP  
3. Mount the outdoor air enthalpy sensor inside the right econo-  
mizer hood on the right side panel of the hood, adjacent  
to the outdoor-air thermistor.  
4. Locate the red, violet, and brown wires near the outdoor  
air thermistor. Remove the splice from the red and violet  
wires. Remove the cap from the brown wire.  
1
5. Install a 4-in. push on terminal (field-supplied) on the  
violet and brown wires.  
6. Connect a 14-in. push on terminal (field provided) to one  
end of a 18-gage, 6-in. jumper wire (field-provided). Con-  
nect the other end to the red wire and attach a 14-in. push  
on connector (field provided).  
7. Connect the red wire with the jumper to terminal TR1.  
Connect the jumper to terminal 2. Connect the brown wire  
to terminal TR. Connect the violet wire to terminal 3. All  
connections are on the enthalpy control.  
Fig. 29 — Adding Foam Strip to Blockoff Baffle  
MOUNTING ANGLE  
(WITHOUT TABS)  
8. Replace the economizer filters.  
9. Return power to unit.  
FILTER TRACK  
ASSEMBLY  
Accessory Differential Enthalpy Control (Fig. 33) — The  
control (HH57AC077), in conjunction with the accessory en-  
thalpy sensor (HH57AC078), controls economizer opera-  
tion according to the differential enthalpy. The control is  
mounted in the economizer hood. The sensor is mounted in  
the return duct (48EJ/EK) or return air plenum (48EW/EY).  
Fig. 30 — Mounting Angle (Without Tabs) Attached  
to Filter Track Assembly  
26  
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5. Turn the enthalpy control set point potentiometer clock-  
wise past the ‘‘D’setting on the enthalpy control to con-  
figure the control to operate on differential enthalpy. See  
Fig. 34.  
6. Remove the return-air enthalpy sensor from the acces-  
sory package. Using the screws provided, mount the sen-  
sor inside the return duct near the unit. Do not locate the  
control too far from the unit, or the wires will not reach  
from the sensor to the control. On 48EW/EY units, the  
enthalpy sensor can be installed in the return air section  
of the unit, under the return air dampers.  
7. Route the wires from the enthalpy sensor to the return  
air enthalpy control through the holes on the inside of  
the hinged filter access panel. The holes are blocked by  
plug buttons which should be removed.  
MOUNTING ANGLE  
(WITH TABS)  
8. Use field-supplied wire ties to attach the violet wire to  
the + terminal and the blue wire to the SR terminal.  
9. Replace economizer filters.  
10. Return power to unit.  
Disable Economizer — For applications where the econo-  
mizer will not be used (areas of high humidity), the econo-  
mizer should be disabled. To disable the economizer, perform  
the following:  
Fig. 31 — Mounting Angle (With Tabs) Attached to  
Filter Track Assembly  
1. Turn of power. Lock out disconnect.  
2. Locate the OAT (Outdoor Air Thermostat) in the right  
hand outdoor air damper area.  
3. Locate the splice connecting the violet wire coming from  
T24 on the base module board to the red wire coming  
from T29 on the base module board. Remove the wire  
nut and break the red to violet wire splice.  
BLACK SEAL STRIP  
(CENTERED)  
4. Cap off both wires. When the connection is broken the  
base module is fooled into thinking that the enthalpy is  
not acceptable and economizer operation is disabled.  
HH57AC077  
ENTHALPY CONTROL  
FILTER COVER  
Fig. 32 — Attaching Seal Strip to Filter Cover  
HH57AC078  
Differential Enthalpy Sensor Installation — To install the con-  
trol, perform the following procedure:  
1. Turn off all power. Ensure disconnect is locked out.  
ENTHALPY SENSOR  
(USED WITH ENTHALPY  
C7400A1004  
CONTROL FOR DIFFERENTIAL  
ENTHALPY OPERATION)  
+
2. Remove the economizer inlet filters from the bottom of  
the right hand economizer hood. See Fig. 24.  
3. Remove the factory-installed, 620-ohm jumper between  
terminals SR and + on the enthalpy control located in-  
side the outdoor air hood.  
Fig. 33 — Differential Enthalpy Control and Sensor  
4. Connect the violet wire from the enthalpy sensor kit to  
the + terminal on the enthalpy control. Connect the blue  
wire from the enthalpy sensor kit to the SR terminal on  
the enthalpy control.  
27  
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CONTROL POINT  
(APPROX. DEG.)  
AT 50% RH  
CONTROL  
CURVE  
A
B
C
D
73 (23)  
70 (21)  
67 (19)  
63 (17)  
NOTE: Switches shown in high enthalpy state. Terminals 2 and 3 close  
on enthalpy decrease.  
Fig. 34 — Wiring Connections for Solid-State  
Enthalpy Control (HH57AC077)  
RH  
Relative Humidity  
Fig. 35 — Psychrometric Chart for  
Enthalpy Control  
NOTE: Partitions shown indicate both side supply (EW/EY) and ver-  
tical supply (EJ/EK) units.  
Fig. 36 — Economizer Details  
28  
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See Fig. 38. A section of field-supplied 14-in. plastic tubing  
must be run from the high pressure tap on the differential  
pressure switch and connected to a field-supplied tap in the  
supply-air duct. The tap is usually located 23 of the way out  
on the main supply duct. Remove plug button in panel to  
route tubing.  
The low pressure tap is factory-routed to the atmo-  
sphere. For a positive-pressure building, route the high tap  
to building air and low tap to atmosphere. For a negative-  
pressure building, route the high tap to atmosphere and the  
low tap to building air.  
Step 10 — Position Power Exhaust/Barometric  
Relief Damper Hood — All electrical connections have  
been made and adjusted at the factory. The power exhaust  
blowers and barometric relief dampers are shipped as-  
sembled and tilted back into the unit for shipping. Brackets  
and extra screws are shipped in shrink wrap around the damp-  
ers. If ordered, each unit will have 4 power exhaust blowers  
and motors or 4 barometric relief dampers.  
1. Remove 9 screws holding each damper assembly in place.  
See Fig. 37. Each damper assembly is secured with 3 screws  
on each side and 3 screws along the bottom. Save screws.  
VAV BUILDING PRESSURE TRANSDUCER — The VAV  
building pressure transducer (modulating power exhaust pres-  
sure transducer) is located behind the filter access door on  
the lower inner panel. See Fig. 38. A section of field-  
supplied 14-in. plastic tubing must be run from the high pres-  
sure tap on the differential pressure switch to the conditioned  
space. The pressure tube must be terminated in the condi-  
tioned space where a constant pressure is required. This lo-  
cation is usually in an entrance lobby so that the building  
exterior doors will open and close properly. Remove plug  
button in panel to route tubing.  
The low pressure tap is factory-routed to the atmo-  
sphere. For a positive-pressure building, route the high tap  
to building air and low tap to atmosphere. For a negative-  
pressure building, route the high tap to atmosphere and the  
low tap to building air.  
Be careful when tilting blower assembly. Hoods and blow-  
ers are heavy and can cause injury if dropped.  
2. Pivot each damper assembly outward until edges of damper  
assembly rest against inside wall of unit.  
3. Secure each damper assembly to unit with 6 screws across  
top (3 screws provided) and bottom (3 screws from  
Step 1) of damper.  
4. With screws saved from Step 1, install brackets on each  
side of damper assembly.  
5. Remove tape from damper blades.  
VAV DUCT PRESSURE TRANSDUCER — The VAV duct  
pressure transducer (VAV inverter pressure transducer) is lo-  
cated behind the filter access door on the lower inner panel.  
NOTES:  
1. Unless otherwise specified, all dimensions are to outside of part.  
2. Dimensions are in inches.  
3. On 48EW,EY units, accessory barometric relief or power exhaust must be mounted in the field-supplied return ductwork.  
Fig. 37 — Barometric Relief Damper and Power  
Exhaust Mounting Details  
29  
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When replacing the OFM, reconnect the black, yellow, and  
blue wires form the outdoor fan contactor to the black, yel-  
low, and blue wires of the Motormaster III control. Run new  
wires from the red, orange, and brown wires to the leads of  
the new OFM. Connect the green wire from the control to  
ground.  
NOTE: On all 575-v units, 2 transformers (part no.  
HT01AH851) must be used for each Motormaster III con-  
trol to lower the supply voltage to the control to 460-v. Trans-  
formers can be mounted anywhere outside the control box.  
Step 11 — Install All Accessories — After all the  
factory-installed options have been adjusted, install all field-  
installed accessories. Refer to the accessory installation in-  
structions included with each accessory.  
MOTORMASTERIII INSTALLATION  
Install Field-Fabricated Wind Baffles — Wind baffles must  
be field-fabricated for all units to ensure proper cooling cycle  
operation at low-ambient temperatures. See Fig. 39 for baffle  
details. Use 20-gage, galvanized sheet metal, or similar  
corrosion-resistant metal for baffles. Use field-supplied screws  
1
to attach baffles to unit. Screws should be 4-in. diameter  
5
and ⁄8-in. long. Holes for wind baffles are pre-punched in  
the unit sheet metal.  
To avoid damage to the refrigerant coils and electrical  
components, use recommended screw sizes only.  
On 48EJ,EK,EW,EY024-034 units, the wind baffles at-  
tach to flanges formed on the outer sheet metal of the unit  
where the condenser coil tube sheets attach.  
On 48EJ,EK,EW,EY038-048 units, the wind baffles at-  
tach to flanges formed on the outer sheet metal of the unit  
corner post. The other end of the baffle is attached to the  
center panel between the condenser coil and the indoor sec-  
tion. Two baffles are required for 48EJ,EK,EW,EY038-048  
units.  
Install Motormaster III Controls — Only one Motormaster  
III control is required per unit.  
Motor — The circuit no. 1 (lead compressor) outdoor-fan  
motor (OFM) will need to be changed out in the field to ac-  
commodate the Motormaster III accessory. The replacement  
motor part no. is HD52AK652.  
VAV — Variable Air Volume  
On 48EJ,EK,EW,EY038-048 units, only one OFM will need  
to be changed out. The no. 1 compressor is located at the left  
side of the unit looking from the compressor end. The circuit  
no. 2 OFMs are controlled to shut off at 55 F and turn on at  
65 F outdoor-air temperature.  
Fig. 38 — Pressure Transducer Locations  
Sensor — Install the sensor for thermistor input control in  
the location shown in Fig. 40A-C. Connect sensor leads to  
the violet and gray control signal leads on the Motormaster  
III control.  
1
BOTH SIDES  
18  
Signal Selection Switch — Remove the cover of the Motor-  
master III control. Set the switch to accept the thermistor  
sensor input signal. Set the frequency to match the unit power  
supply (60 Hz).  
Motormaster III Control — The recommended mounting lo-  
cation is in the indoor fan section, mounted on the panel that  
separates the indoor and outdoor sections. On VAV units,  
this location is next to the VFD.  
77.7  
0.312 DIA  
HOLES  
61  
17.167  
BETWEEN  
HOLES  
Do not route the Motormaster III wiring next to the VFD  
on VAV units. Use a separate connector through the partition  
when wiring to the OFM.  
(TYPICAL)  
CROSS-BREAK  
78.7  
0.5  
Electrical Connections  
4.62  
NOTE: All dimensions are in inches. Material: 20 gage galvanized  
steel or other non-corrosive material.  
To avoid possibility of electrical shock and personal in-  
jury, turn off all power to unit before making electrical  
connections.  
Fig. 39 — Motormaster III Baffle Details  
30  
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Fig. 40A — Motormaster III Sensor Location  
(Sizes 024-034)  
Fig. 40C — Motormaster III Sensor Location  
(Size 048)  
Internal Wiring — Check all electrical connections in  
unit control boxes; tighten as required.  
Refrigerant Service Ports — Each refrigerant sys-  
tem has one suction port located in the top of the compressor  
motor casing. All units also have one service port on the liq-  
uid line valve and one on the compressor discharge valve.  
Be sure that caps on the ports are tight.  
Crankcase Heaters — Crankcase heaters are ener-  
gized as long as there is power to the unit, except when the  
compressors are operating.  
IMPORTANT: Unit power must be on for 24 hours  
prior to start-up. Otherwise, damage to compressor may  
result.  
Variable Frequency Drive (VFD) — The variable  
frequency drives are factory set. These settings include factory-  
installed jumpers and software configurations. The only  
field configured set point is duct static pressure. An Opera-  
tion Manual is shipped with each VAV unit. This manual should  
be used if the drive needs to be customized for a particular  
application.  
Fig. 40B — MotormasterIII Sensor Location  
(Sizes 038 and 044)  
NOTE: The VFD will always provide the proper phase  
sequence to the indoor-fan motor. The indoor-fan motor op-  
erates in proper rotation regardless of the phase sequence to  
the unit. If, upon start-up, the outdoor fans operate back-  
wards but the indoor fan operates in the correct direction,  
reverse any two leads to the main terminal block. All fans  
will then operate in the correct direction.  
START-UP  
Use the following information and Start-Up Checklist  
on page CL-1 to check out unit PRIOR to start-up.  
Unit Preparation — Check that unit has been installed  
in accordance with these installation instructions and appli-  
cable codes.  
To set the duct static pressure, perform the following steps.  
The factory setting is zero. The duct transducer has a range  
from 0 to 5 in. wg. The transducer output is 4 to 20 mA,  
therefore, 0 to 5 in. wg is proportional to the 4 to 20 mA and  
must be expressed to the VFD in terms of percentage of the  
frequency range. Refer to Table 7. The set point value is a  
percentage of the maximum output frequency. Locate the duct  
static pressure closest to that desired and use the correspond-  
ing set point value. If necessary, interpolation between duct  
static pressures is permissible.  
Compressor Mounting — Loosen the compressor hold-  
down bolts until sidewise movement of the washer under  
each holddown bolt head can be obtained. Do not loosen  
completely as bolts are self-locking and will maintain  
adjustment.  
Service Valves — Ensure that the suction, discharge,  
and liquid line service valves are open. Damage to the com-  
pressor could result if they are left closed.  
31  
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To set the VFD, the VFD must be powered up; however,  
since it is located near the indoor air fan, operation of the  
fan is not desirable. To disable the fan, perform the follow-  
ing procedure:  
the base module closes contacts, activating two exhaust fans.  
When the economizer position reaches 75% open, the base  
module activates the other two exhaust fans. The fans will  
turn off when the economizer closes below the same points.  
The economizer position set points that trigger the exhaust  
fans can be modified, but only through use of the Service  
Tool, Comfort Works, or Building Supervisor software. If  
single-stage operation is desired, adjust the economizer set  
points to identical values at the desired point to activate all  
exhaust fans.  
1. Open the indoor fan circuit breaker.  
2. Remove the jumper between CC and ST on the terminal  
strip of the VFD (see Fig. 41).  
3. Close the indoor fan circuit breaker. The VFD now is  
powered but the fan will not operate.  
4. On the front of the VFD is a keypad and display which  
will be used to enter the set point. To access this field,  
press the ‘‘PRG’’ key until the display reads ‘‘S.PrG’’  
(Speed Group Parameters). Press the arrow key until ‘‘Sr1’’  
is displayed. This is the VFD set point listed in Table 7.  
5. Press the ‘‘READ/WRITE’key. The set point value will  
be displayed. Use the up-arrow or down-arrow key to  
adjust the set point value to the value desired.  
6. Press the ‘‘READ/WRITE’’ key again to enter the new  
value.  
7. Check the factory default values.  
The optional modulating power exhaust (VAV standard,  
CV optional) is controlled by a modular electronic se-  
quencer system. This system consists of a model R353 sig-  
nal input module and 4 model S353 staging modules. The  
signal input module receives a 0 to 10 vdc signal from the  
building pressure transducer, which is mounted adjacent to  
the supply static transducer behind the filter access panel.  
The modules are mounted just below the unit control board.  
The left module is the R353, and the 4 modules on the right  
are S353 modules for stages 1 through 4. On the unit wiring  
label, the R353 is designated PESC, and the S353 modules  
are designated PES1 through PES4.  
The building pressure transducer range is −0.5 to  
+ 0.5 in. wg. It is powered by a 0 to 10 vdc signal. A factory-  
installed hose at the ‘‘Lo’’ connection leads to atmosphere,  
and a field-supplied hose must be connected to the ‘‘Hi’con-  
nection and led into the building to a point where building  
pressure is to be controlled (positive-pressure building). There  
is a plug button in the bulkhead just above the transducers,  
for use in leading the hoses into the building via the return  
air ductwork.  
There are 3 adjustments at the R353 module, all of which  
have been factory set. In the center of the circuit board is  
a set of 4 pins with a jumper, labeled J2. This determines the  
mode of operation. The bottom two pins must be jumpered  
for direct operation. Direct operation means that the stag-  
ing modules are activated in sequence as the input signal  
increases.  
IMPORTANT: The Carrier factory default values  
for the VFD may be different than the default val-  
ues of the manufacturer. Refer to the Carrier lit-  
erature when checking default values. The following  
default values have been changed from the manu-  
facturer settings to more closely match the VFD  
operation to a Carrier VAV unit.  
SETUP PARAMETERS (Item 6, Point 1, Output Fre-  
quency) — The default value should be 20.  
JUMP FREQUENCY GROUP (Item 7, PID Set Point  
Control Select) — The default value is 1.  
JUMP FREQUENCY GROUP (Item 8, Proportional Gain)  
— The default value is 100.  
JUMP FREQUENCY GROUP (Item 9, Integral Gain)  
— The default value is 50.  
SPEED GROUP PARAMETERS (Item 2, Multi-Speed  
Run Frequency No. 1) — The factory setting is 30.  
Table 7 — VFD Supply Air Pressure Set Point  
SPEED GROUP PARAMETERS (Item 2, Fire Speed  
Override Frequency) — The factory setting is 60.  
8. Open the indoor fan circuit breaker.  
9. Replace the jumper between CC and ST on the terminal  
strip of the VFD.  
10. Close the indoor fan circuit breaker; the VFD now is  
powered and the fan will operate.  
PRESSURE  
(in. wg)  
CONTROL  
(mA)  
VFD  
SET POINT  
0
4.0  
4.8  
0
3
0.25  
0.50  
0.75  
1.00  
1.25  
1.50  
1.75  
2.00  
2.25  
2.50  
2.75  
3.00  
3.25  
3.50  
5.6  
6
6.4  
9
7.2  
12  
15  
18  
21  
24  
27  
30  
33  
36  
39  
42  
8.0  
8.8  
9.6  
NOTE: Any field measurement of supply fan amps must be  
taken with an RMS meter between the fan circuit breaker  
and fan contactor (upstream of VFD).  
10.4  
11.2  
12.0  
12.8  
13.6  
14.4  
15.2  
Power Exhaust — The optional non-modulating power  
exhaust (CV only) is a two-stage design where the operation  
of the exhaust fans is linked to economizer position. When  
the supply fan is running and the economizer is 25% open,  
VFD  
Variable Frequency Drive  
(SS2) (SS3)  
FLA FLB FLC P24 RCH LOW FM  
AM  
PP  
RR  
IV  
CC  
ST  
F
R
CC  
SS1 JOG AD2 RST CC  
+
NOTE: Terminal strip is located inside the VFD at the bottom.  
JUMPERS  
D P D P  
Fig. 41 — VFD Factory-Installed Jumpers  
32  
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At the upper right corner of the board is a set of 5 pins and  
jumper, which determines the time constant for the control.  
The time constant is the delay in response built into the con-  
trols. The jumper should be on the middle or bottom two  
pins, for the maximum time constant. The delay can be  
decreased, if desired, by moving the jumper progressively  
upward, always jumpering adjacent pins.  
At the lower left corner of the board below the terminal  
strip is a resistor marked R27. This must be removed in  
order to obtain the 0 to 10 vdc signal output. There will not  
be a resistor on a factory-supplied module, but a resistor may  
be present on a replacement module and must be removed.  
brated in 1% increments, and is factory set at approximately  
3%. It is recommended to leave the set point at 3%, to mini-  
mize cycling of the fans.  
The offset and differential potentiometers have been fac-  
tory set for atmospheric pressure. Do not change these  
settings until there is some experience with the building. In  
most cases the factory settings will be satisfactory. How-  
ever, if the building pressure is not being maintained as de-  
sired, then some minor adjusting on a trial and error basis  
can be made.  
The R353 module has a terminal block with 7 connec-  
tions available for wiring. The 2 right-hand terminals are for  
the 24 vac and common connections. The next 2 terminals  
are for the 0 to 10 vdc signal. Consult the wiring label for  
wire identification if replacing the module. The 3 left-hand  
terminals are not used for this application.  
The S353 module has an LED (light-emitting diode), a set  
of 4 jumper pins, and 2 potentiometers. The LED will light  
whenever the module is activated, providing a visual indi-  
cation of the number of exhaust fans running. The jumper  
pins are arranged in a square format. Two jumpers are used  
to determine the mode of operation (direct or reverse). The  
2 jumpers must be arranged horizontally for direct action  
(factory set).  
Direct Digital Controls DIP Switch Configura-  
tion — The Direct Digital Control (DDC) board must be  
configured for each application. The DDC board is config-  
ured through the DIP switches located on the board. There  
are 8 DIP switches which configure 8 different applications  
of the DDC. See Table 10. DIP switch 1 is on the left of the  
block. DIP switch 8 is on the right of the block. To open a  
DIP switch, push the switch up with suitable tool (small-  
blade screwdriver). To close a DIP switch, push the switch  
down. Factory settings are shown in Table 11.  
The DIP switch configurations are as follows:  
• DIP switch 1 configures the unit to operate as a VAV or  
CV unit  
• DIP switch 2 configures the unit to use a space sensor (VAV  
units) or a thermostat (CV units)  
At the top of the module are two potentiometers. The left  
potentiometer adjusts the offset. The right potentiometer  
adjusts the differential. The potentiometers are factory set  
for a nominal 0 in. wg building pressure.  
• DIP switch 3 configures the DDC for use with an elec-  
tronic expansion board  
• DIP switch 4 is used to field test the unit  
• DIP switch 5 is used to enable occupied heating (VAV units)  
or specify the type of power exhaust (CV units)  
• DIP switch 6 configures the Time Guardoverride and,  
when used with the field test function, sets the minimum  
damper position  
The offset set point is defined as the point at which a mod-  
ule turns off a fan, and is measured in terms of percent of the  
input signal. For control purposes, 0 offset is at an arbitrary  
‘‘floor’’ which is established at 10% of the input signal, or  
1 vdc. In this example, the first stage will turn off at 30%  
(3 vdc), and the offset potentiometer will be set at 20%.  
The second stage will turn off at 50% signal (5 vdc), and the  
offset potentiometer will be set at 40%. The fourth stage is  
at the maximum 75% offset, which equates to 85% signal  
or 8.5 vdc. The offset potentiometer is calibrated in 10%  
increments.  
• DIP switch 7 configures the unit for gas heat or electric  
heat  
• DIP switch 8 configures the unit for heat pump or air con-  
ditioner operation.  
Crankcase Heater — Units are equipped with crank-  
case heaters. Crankcase heaters are energized as long as there  
is power supplied to unit. Crankcase heaters deenergize while  
compressors are running.  
Table 8 relates building pressure to signal level.  
Table 8 — Potentiometer Signal Levels  
BUILDING PRESSURE  
(in. wg)  
SIGNAL LEVEL  
(vdc)  
IMPORTANT: To prevent damage to compressors, crank-  
case heater should be energized 24-hours prior to  
start-up.  
−0.50  
−0.25  
0.00  
2
4
6
0.25  
8
Evaporator Fan — Fan belt and fixed pulleys are factory-  
installed. See Tables 12-16 for fan performance and motor  
limitations data. Remove tape from fan pulley, and be sure  
that fans rotate in the proper direction. See Table 17 for air  
quantity limits. Static pressure drop for power exhaust is neg-  
ligible. To alter fan performance, see Evaporator Fan  
Performance Adjustment section on page 46.  
0.50  
10  
If the building pressure is controlled at 0 in. wg, offset of  
the first stage should be set at 50%, which equates to 60%  
of the input signal, or 6 vdc. The other stages can then be set  
as desired between 50% and 75%.  
The default offset set points for modulating power ex-  
haust are shown in Table 9.  
The differential set point is the difference between the  
turn off point and the turn on point for each module. It also  
is calibrated in terms of percent of input signal, and has a  
range of 1% to 7%. The differential potentiometer is cali-  
Condenser Fans and Motors — Condenser fans and  
motors are factory set. Refer to Condenser-Fan Adjustment  
section on page 47 as required. Be sure that fans rotate in  
the proper direction. Fan no. 2 (sizes 024-034) and fans  
no. 3 and 4 (sizes 038-048) are cycled on the outdoor-air  
temperature.  
33  
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Table 9 — Power Exhaust Default Set Points  
OFF STATIC PRESSURE  
(in. wg)  
STAGE  
OFFSET  
DIFFERENTIAL  
OFF VOLTAGE  
ON VOLTAGE  
1
2
3
4
50%  
55%  
60%  
64%  
3%  
3%  
3%  
3%  
6.0  
6.5  
7.0  
7.4  
6.3  
6.8  
7.3  
7.7  
0.00  
0.06  
0.12  
0.18  
Table 10 — DIP Switch Configuration  
SETTING  
OPEN  
1
2
3
4
5
6
7
8
VAV —  
VAV — Space Sensor  
Installed  
Occupied Time GuardOverride  
Heat  
Enabled  
ON  
Expansion  
Board  
Field Test  
ON  
Heat Pump  
Operation  
VAV  
Gas Heat  
CV —  
Modulated  
Power  
IN CONJUNCTION  
WITH FIELD TEST  
— Set Minimum  
CV — CCN or Sensors  
Used  
Exhaust  
Damper Position  
VAV —  
Occupied  
Heat  
VAV — No Space Sensor  
CV — Thermostat  
Disabled  
Base Control Field Test  
Board Only OFF  
Time Guard Override  
OFF  
Air Conditioner  
Operation  
CLOSED CV  
Electric Heat  
CV —  
Constant  
Volume  
Power  
Exhaust  
LEGEND  
NOTES:  
1. The OPEN side of the DIP switch is marked ‘‘OPEN.’’ When the  
rocker switch is on the ‘‘OPEN’’ side of the switch, the switch is  
OPEN.  
CCN  
CV  
VAV  
Carrier Comfort Network  
Constant Volume  
Variable Air Volume  
2. The configuration of DIP switches 2 and 5 are dependent on DIP  
switch 1. If DIP switch 1 is set to OPEN (VAV operation), then DIP  
switches 2 and 5 will configure VAV functions.  
3. When the unit is field-tested (DIP switch 4 to OPEN), the function  
of DIP switch 6 changes and it is used to set the minimum damper  
position.  
Table 11 — DIP Switch Factory Settings  
UNIT  
1
2
3
4
5
6
7
8
48EJ,EW  
48EK,EY  
Closed  
Open  
Closed  
Closed  
Closed  
Closed  
Closed  
Closed  
Closed  
Closed  
Closed  
Closed  
Open  
Open  
Closed  
Closed  
34  
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Table 12 — Fan Performance, 48EJ/EK024-034 — Vertical Discharge Units  
(For EW/EY units, reduce net available external static pressure by 0.3 in. wg)  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
1.4  
1.6  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
4,000  
5,000  
340  
384  
432  
483  
536  
549  
590  
645  
701  
757  
786  
0.83  
1.25  
1.79  
2.48  
3.33  
3.57  
4.34  
5.54  
6.92  
8.49  
9.36  
416  
453  
495  
540  
588  
600  
637  
689  
741  
795  
822  
1.17  
1.61  
2.19  
2.91  
3.78  
4.02  
4.82  
6.04  
7.44  
9.04  
9.92  
480  
513  
550  
591  
635  
646  
681  
729  
779  
830  
856 10.47  
883 11.41  
922 12.92  
936 13.45  
1.52  
1.99  
2.59  
3.33  
4.23  
4.48  
5.30  
6.54  
7.96  
9.59  
537  
566  
600  
638  
679  
690  
722  
768  
816  
865 10.14  
890 11.03  
915 11.98  
953 13.51  
966 14.05  
1.90  
2.39  
3.01  
3.77  
4.69  
4.95  
5.78  
7.04  
8.49  
588  
615  
647  
682  
720  
730  
762  
805  
850  
2.29  
2.79  
3.43  
4.22  
5.16  
5.42  
6.27  
7.56  
9.03  
635  
660  
690  
723  
759  
769  
799  
840  
884  
2.69  
3.21  
3.87  
4.67  
5.64  
5.90  
6.77  
8.07  
9.56  
679  
703  
730  
762  
797  
806  
834  
874  
3.11  
3.64  
4.31  
5.14  
6.12  
6.39  
7.27  
8.59  
720  
742  
769  
799  
832  
841  
868  
906  
3.53  
4.08  
4.77  
5.61  
6.61  
6.88  
7.77  
9.12  
6,000  
7,000  
8,000  
8,250  
9,000  
10,000  
11,000  
12,000  
12,500  
13,000  
13,750  
14,000  
15,000  
916 10.10  
960 11.81  
947 10.65  
990 12.37  
898 10.69  
922 11.60  
946 12.56  
929 11.25  
953 12.16  
983 12.73 1012 13.31  
814 10.28  
857 11.75  
871 12.27  
929 14.50  
849 10.84  
890 12.34  
904 12.86  
960 15.10  
976 13.13 1006 13.71 1034 14.30  
983 14.10 1012 14.69 1041 15.28 1068 15.88  
996 14.64 1025 15.23 1053 15.83 1080 16.43  
990 15.71 1019 16.33 1047 16.94 1074 17.55 1101 18.17 1127 18.79  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
1.8  
2.0  
2.2  
2.4  
2.6  
2.8  
3.0  
3.2  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
4,000  
5,000  
759  
780  
805  
834  
866  
874  
901  
938  
3.97  
4.53  
5.23  
6.09  
7.10  
7.38  
8.29  
9.65  
796  
816  
840  
868  
899  
907  
932  
4.42  
4.99  
5.70  
6.57  
7.60  
7.89  
8.80  
831  
851  
874  
901  
930  
938  
963  
4.87  
5.45  
6.18  
7.07  
8.11  
8.40  
9.33  
865  
884  
906  
932  
961  
968  
992  
5.34  
5.93  
6.67  
7.56  
8.62  
8.92  
897  
916  
937  
962  
990  
998  
5.81  
6.41  
7.16  
8.07  
929  
946  
968  
992  
6.30  
6.90  
7.66  
959  
976  
997  
6.79  
988  
7.28  
7.91  
8.69  
9.63  
7.40 1005  
8.17 1025  
9.10 1048  
6,000  
7,000  
8.58 1020  
8,000  
9.14 1019  
9.44 1026  
9.67 1047 10.20 1074 10.74  
9.97 1054 10.50 1081 11.04  
8,250  
9,000  
9.86 1021 10.39 1049 10.93 1076 11.48 1102 12.03  
10,000  
11,000  
12,000  
12,500  
13,000  
13,750  
14,000  
15,000  
968 10.18  
997 10.72 1026 11.27 1054 11.82 1081 12.37 1107 12.93 1133 13.49  
977 11.19 1006 11.75 1035 12.30 1062 12.87 1089 13.43 1115 14.00 1141 14.57 1166 15.15  
1019 12.94 1047 13.51 1074 14.08 1100 14.66 1126 15.24 1152 15.83 1177 16.42 1201 17.01  
1040 13.88 1067 14.46 1094 15.05 1120 15.63 1146 16.22 1171 16.82 1195 17.41  
1062 14.88 1089 15.47 1115 16.06 1140 16.66 1166 17.25 1190 17.86  
1095 16.48 1121 17.08 1147 17.68 1172 18.29 1196 18.90  
1106 17.04 1132 17.64 1157 18.25 1182 18.86  
1152 19.41 1177 20.04 1200 20.66  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
3.4 3.6 3.8  
AIRFLOW  
(Cfm)  
LEGEND  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Bhp  
Brake Horsepower  
4,000  
5,000  
1017  
1033  
1053  
1075  
1100  
1107  
1128  
1158  
1190  
7.79  
8.42  
9.21  
10.16  
11.28  
11.59  
12.58  
14.06  
15.74  
1045  
1061  
1080  
1102  
1126  
1133  
1153  
1183  
8.30  
8.94  
9.73  
10.69  
11.83  
12.14  
13.14  
14.63  
1072  
1087  
1106  
1127  
1151  
1158  
1178  
8.82  
9.46  
10.27  
11.24  
12.38  
12.69  
13.70  
NOTES:  
1. Fan performance is based on wet coils, economizer, roof curb,  
cabinet losses, and clean 2-in. filters.  
6,000  
7,000  
2. Conversion — Bhp to watts:  
8,000  
Bhp x 746  
Watts =  
8,250  
9,000  
Motor efficiency  
10,000  
11,000  
12,000  
12,500  
13,000  
13,750  
14,000  
15,000  
3. Variable Air Volume units will operate down to 70 cfm/ton. Per-  
formance at 70 cfm/ton is limited to unloaded operation and may  
be additionally limited by edb (entering dry bulb) and ewb (enter-  
ing wet bulb) conditions.  
35  
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Table 13 — Fan Performance, 48EJ,EK038,044 — Vertical Discharge Units  
(For EW/EY units, reduce net available external static pressure by 0.5 in. wg)  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
1.4  
1.6  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
7,000  
8,000  
429  
475  
523  
571  
620  
670  
720  
771  
822 10.88  
873 12.80  
924 14.91  
976 17.24  
1.70  
2.36  
3.11  
4.00  
5.04  
6.24  
7.61  
9.15  
484  
525  
567  
612  
658  
705  
752  
801 10.97  
850 12.95  
899 15.16  
949 17.59  
2.40  
3.09  
3.97  
5.01  
6.22  
7.61  
9.19  
536  
571  
610  
651  
694  
738  
784  
830 11.51  
877 13.52  
925 15.74  
974 18.20  
2.70  
3.49  
4.39  
5.46  
6.69  
8.10  
9.70  
584  
616  
651  
689  
729  
771  
814 10.23  
859 12.05  
904 14.08  
951 16.33  
3.10  
3.90  
4.82  
5.91  
7.17  
8.60  
630  
658  
690  
725  
763  
803  
844 10.75  
887 12.60  
931 14.65  
3.50  
4.31  
5.26  
6.37  
7.65  
9.11  
674  
699  
728  
761  
796  
834  
874 11.29  
915 13.15  
957 15.22  
3.90  
4.74  
5.71  
6.84  
8.14  
9.62  
716  
738  
765  
795  
829  
865 10.13  
902 11.82  
942 13.71  
4.30  
5.17  
6.16  
7.31  
8.64  
756  
776  
801  
829  
860  
894 10.65  
931 12.36  
969 14.27  
4.80  
5.61  
6.62  
7.79  
9.14  
9,000  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
983 15.80 1008 16.38  
976 16.92 1001 17.51 1025 18.11 1049 18.71  
998 18.80 1022 19.41 1045 20.03 1069 20.64 1092 21.26  
999 20.26 1023 20.88 1046 21.51 1068 22.14 1091 22.77 1113 23.41 1135 24.05  
1027 19.77 1050 23.17 1072 23.82 1094 24.46 1115 25.11 1137 25.76 1158 26.42 1179 27.07  
1079 22.53 1100 26.33 1122 27.00 1142 27.66 1163 28.33 1183 29.00  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
1.8  
2.0  
2.2  
2.4  
2.6  
2.8  
3.0  
3.2  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
7,000  
8,000  
794  
813  
835  
862  
891  
5.20  
6.06  
7.09  
8.28  
9.64  
832  
848  
869  
893  
5.62  
6.52  
7.56  
8.77  
868  
883  
902  
925  
6.06  
6.98  
8.04  
9.27  
903  
916  
934  
955  
6.52  
7.45  
8.53  
9.77  
937  
949  
965  
6.98  
7.92  
9.02  
971  
981  
995  
7.44 1003  
8.40 1012  
7.92 1035  
8.89 1042  
8.40  
9.38  
9,000  
9.52 1025 10.02 1054 10.53  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
985 10.28 1014 10.79 1043 11.31 1071 11.84  
921 10.15  
952 11.71  
951 10.67  
980 11.19 1008 11.71 1036 12.24 1064 12.78 1090 13.32  
924 11.18  
958 12.91  
980 12.24 1008 12.78 1035 13.32 1062 13.87 1088 14.42 1114 14.98  
986 13.45 1012 14.01 1039 14.56 1064 15.13 1090 15.69 1115 16.26 1140 16.83  
995 14.83 1021 15.40 1046 15.97 1071 16.55 1096 17.13 1120 17.71 1144 18.29 1168 18.89  
1033 16.96 1058 17.55 1082 18.14 1106 18.73 1130 19.33 1153 19.93 1176 20.54 1199 21.14  
1073 19.31 1097 19.92 1120 20.52 1143 21.14 1165 21.75 1188 22.37  
1114 21.88 1137 22.51 1159 23.13 1181 23.76  
1156 24.69 1178 25.33 1199 25.98  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
3.4 3.6 3.8  
AIRFLOW  
(Cfm)  
LEGEND  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
7,000  
8,000  
1066  
1072  
1083  
1098  
1117  
1139  
1164  
1191  
8.88  
9.88  
11.04  
12.37  
13.86  
15.54  
17.41  
19.48  
1096  
1101  
1111  
1125  
1143  
1164  
1188  
9.38  
10.39  
11.56  
12.90  
14.41  
16.11  
17.99  
1125  
1130  
1139  
1152  
1169  
1189  
9.88  
10.90  
12.08  
13.44  
14.96  
16.68  
Bhp  
Brake Horsepower  
NOTES:  
9,000  
1. Fan performance is based on wet coils, economizer, roof curb,  
cabinet losses, and clean 2-in. filters.  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
2. Conversion — Bhp to watts:  
Bhp x 746  
Watts =  
Motor efficiency  
3. Variable Air Volume units will operate down to 70 cfm/ton. Per-  
formance at 70 cfm/ton is limited to unloaded operation and may  
be additionally limited by edb (entering dry bulb) and ewb (enter-  
ing wet bulb) conditions.  
36  
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Table 14 — Fan Performance, 48EJ,EK048 — Vertical Discharge Units  
(For EW/EY units, reduce net available external static pressure by 0.5 in. wg)  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
1.4  
1.6  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
9,000  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
528  
577  
627  
677  
728  
779  
830 11.03  
882 12.97  
934 15.12  
3.20  
4.10  
5.10  
6.30  
7.71  
9.28  
572  
617  
664  
711  
760  
809 11.11  
858 13.13  
908 15.36  
959 17.83  
4.00  
5.10  
6.30  
7.70  
9.31  
615  
657  
700  
745  
791  
838 11.65  
886 13.69  
934 15.95  
4.40  
5.50  
6.80  
8.20  
9.83  
656  
694  
735  
778  
822 10.35  
867 12.20  
913 14.26  
960 16.54  
4.90  
6.00  
7.30  
8.70  
695  
731  
769  
809  
851 10.88  
895 12.75  
939 14.83  
5.30  
6.40  
7.70  
9.20  
733  
766  
802  
841  
881 11.42  
923 13.31  
966 15.41  
5.80  
6.90  
8.20  
9.70  
769  
801  
835  
871 10.20  
909 11.95  
950 13.87  
6.20  
7.40  
8.70  
805  
834  
866  
901 10.80  
938 12.50  
976 14.43  
6.70  
7.90  
9.20  
991 15.99 1017 16.57  
985 17.13 1010 17.73 1034 18.33 1058 18.93  
983 18.44 1008 19.05 1031 19.66 1055 20.28 1078 20.89 1101 21.52  
986 17.47 1010 20.53 1033 21.16 1056 21.79 1078 22.42 1101 23.06 1123 23.70 1145 24.34  
1038 20.05 1061 23.49 1083 24.13 1105 24.78 1126 25.44 1147 26.09 1169 26.75 1190 27.41  
1091 22.84 1112 26.69 1133 27.36 1154 28.03 1174 28.70 1195 29.37  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
AIRFLOW  
(Cfm)  
1.8  
2.0  
2.2  
2.4  
2.6  
2.8  
3.0  
3.2  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
9,000  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
839  
866  
897  
7.10  
8.40  
9.70  
873  
898  
7.62  
8.85  
905  
929  
8.10  
9.34  
937  
959  
8.59  
9.85  
968  
9.08  
999  
9.57 1028 10.08 1057 10.58  
989 10.36 1018 10.87 1047 11.39 1075 11.91  
927 10.24  
958 11.82  
956 10.76  
985 11.28 1013 11.81 1041 12.34 1068 12.87 1095 13.41  
930 11.30  
965 13.04  
986 12.36 1014 12.90 1041 13.44 1067 13.99 1093 14.54 1119 15.10  
992 13.59 1019 14.15 1045 14.71 1071 15.27 1096 15.84 1121 16.41 1146 16.98  
1002 14.99 1028 15.56 1054 16.14 1079 16.71 1103 17.30 1127 17.88 1151 18.47 1175 19.06  
1041 17.15 1066 17.74 1090 18.34 1114 18.93 1138 19.53 1161 20.13 1184 20.74  
1082 19.52 1105 20.14 1128 20.75 1151 21.37 1174 21.99 1196 22.61  
1124 22.14 1146 22.77 1168 23.40 1190 24.03  
1166 24.98 1188 25.63  
LEGEND  
AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)  
3.4 3.6 3.8  
AIRFLOW  
(Cfm)  
Bhp  
Brake Horsepower  
Rpm  
Bhp  
Rpm  
Bhp  
Rpm  
Bhp  
NOTES:  
1. Fan performance is based on wet coils, economizer, roof curb,  
cabinet losses, and clean 2-in. filters.  
9,000  
10,000  
11,000  
12,000  
13,000  
14,000  
15,000  
16,000  
17,000  
18,000  
19,000  
20,000  
1086  
1102  
1122  
1144  
1170  
1198  
11.10  
12.44  
13.96  
15.66  
17.56  
19.66  
1114  
1129  
1147  
1169  
1194  
11.61  
12.97  
14.51  
16.23  
18.14  
1141  
1155  
1173  
1194  
12.14  
13.51  
15.06  
16.80  
2. Conversion — Bhp to watts:  
Bhp x 746  
Watts =  
Motor efficiency  
3. Variable Air Volume units will operate down to 70 cfm/ton. Per-  
formance at 70 cfm/ton is limited to unloaded operation and may  
be additionally limited by edb and ewb conditions.  
37  
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Table 15 — Fan Performance — Power Exhaust  
48EJ,EK,EW,EY024-048 (20 THRU 45 TONS)  
Low Speed  
230, 460, 575 v  
ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts  
Medium Speed  
High Speed  
Airflow  
(Cfm)  
208 v  
208 v  
230, 460, 575 v  
208 v 230, 460, 575 v  
6,500 0.32 2.82 3160 0.70 2.98 3340  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
6,700 0.23 2.87 3220 0.63 3.03 3400 0.60 3.01 3380 0.82 3.23 3620  
6,900 0.17 2.92 3270 0.59 3.09 3460 0.55 3.07 3440 0.78 3.28 3680  
7,100 0.13 2.93 3290 0.56 3.11 3490 0.49 3.12 3500 0.73 3.34 3740  
7,300 0.09 2.97 3330 0.53 3.15 3530 0.43 3.18 3560 0.68 3.39 3800  
7,500  
7,700  
7,900  
8,100  
8,500  
8,900  
9,300  
9,700  
10,100  
10,500  
10,900  
11,300  
11,700  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
0.51 3.19 3580 0.39 3.24 3630 0.64 3.44 3860  
0.48 3.23 3620 0.33 3.27 3670 0.59 3.48 3900 0.60 3.69 4140 0.73 3.98 4460  
0.45 3.27 3670 0.27 3.32 3720 0.54 3.52 3950 0.56 3.74 4190 0.69 4.02 4510  
0.40 3.33 3730 0.22 3.36 3770 0.49 3.57 4000 0.51 3.78 4240 0.65 4.07 4560  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
0.17 3.47 3890 0.40 3.67 4120 0.41 3.83 4290 0.56 4.12 4620  
0.00 3.58 4010 0.30 3.77 4230 0.31 3.93 4410 0.47 4.23 4740  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
0.22 3.87 4340 0.20 4.07 4560 0.37 4.37 4900  
0.16 3.95 4430 0.11 4.17 4670 0.30 4.47 5010  
0.12 4.03 4520 0.04 4.25 4770 0.23 4.56 5110  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
—-  
0.17 4.66 5220  
0.12 4.75 5330  
0.07 4.80 5380  
0.04 4.83 5420  
LEGEND  
Bhp  
Brake Horsepower  
External Static Pressure (in. wg)  
Input Watts to Motor  
ESP  
Watts  
Table 16 — Motor Limitations  
STANDARD EFFICIENCY MOTORS  
Maximum Amps  
Nominal  
Hp  
Maximum  
Bhp  
Maximum  
Watts  
Motor  
Efficiency  
230  
460  
575  
5.9  
5.9  
14.6  
5,030  
5,030  
87.5  
87.5  
88.5  
88.5  
89.5  
89.5  
91.0  
91.0  
91.0  
91.0  
91.7  
91.7  
92.4  
92.4  
5
7.9  
6.0  
8.7  
22.0  
7,334  
7.5  
10  
15  
20  
25  
30  
9.5  
12.0  
10.0  
8,008  
10.2  
11.8  
15.3  
18.0  
22.4  
23.4  
28.9  
29.4  
35.6  
34.7  
28.0  
8,502  
14.6  
12.0  
9,836  
43.8  
12,543  
14,756  
18,363  
19,183  
23,511  
23,918  
28,742  
28,015  
21.9  
19.0  
62.0  
28.7  
23.0  
72.0  
37.4  
31.0  
95.0  
48.0  
47.0  
HIGH EFFICIENCY MOTORS  
Maximum Amps  
Nominal  
Hp  
Maximum  
Maximum  
Motor  
Bhp  
Watts  
Efficiency  
230  
15.8  
460  
5.9  
5.9  
4,918  
4,918  
89.5  
89.5  
91.7  
91.7  
91.7  
91.7  
93.0  
93.0  
93.6  
93.6  
93.6  
93.6  
93.6  
93.6  
5
7.9  
8.7  
22.0  
7,078  
7.5  
10  
15  
20  
25  
30  
9.5  
12.0  
7,728  
10.2  
11.8  
15.3  
18.0  
22.4  
23.4  
28.9  
29.4  
35.6  
34.7  
28.0  
8,298  
15.0  
9,600  
43.8  
12,273  
14,439  
17,853  
18,650  
23,034  
23,432  
28,374  
27,656  
21.9  
58.2  
28.7  
73.0  
36.3  
82.6  
41.7  
BHP — Brake Horsepower  
NOTE: Extensive motor and electrical testing on the Carrier units has ensured that the full horsepower range of the motor can be utilized with  
confidence. Using your fan motors up to the horsepower ratings shown on the Motor Limitations table will not result in nuisance tripping or premature  
motor failure. Unit warranty will not be affected.  
38  
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Table 17 — Air Quantity Limits  
MINIMUM COOLING  
MINIMUM HEATING  
AIRFLOW  
MINIMUM HEATING  
AIRFLOW  
UNIT  
48EJ,EK,EW,EY  
AIRFLOW (VAV)  
AT FULL LOAD  
OPERATION  
MINIMUM COOLING  
AIRFLOW (CV)  
MAXIMUM  
AIRFLOW  
(Low Heat)  
(High Heat)  
024  
028  
030  
034  
038  
044  
048  
5730  
5730  
5730  
5730  
7360  
7360  
7360  
5950  
5950  
5950  
5950  
9820  
9820  
9820  
2000  
2500  
2750  
3000  
3500  
4000  
4500  
6,000  
7,500  
10,000  
12,500  
13,750  
15,000  
17,500  
20,000  
22,500  
8,250  
9,000  
10,500  
12,000  
13,500  
LEGEND  
CV  
VAV  
Constant Volume  
Variable Air Volume  
open,then sensors are employed. If switch no. 2 is closed,  
thermostat is employed. Initialization clears all alarms and  
alerts, remaps the input/output database for CV operation,  
sets maximum heat stages to 2, and sets maximum cool stages  
to 3. The control reads DIP switch no. 3 and if open, then it  
sets the internal flag for expansion mode operation.  
The first time power is sent to the control board after a  
power outage, power up takes 5 minutes plus a random 1 to  
63 seconds.  
The TSTAT function performs a thermostat based control  
by monitoring Y1, Y2, W1, W2, and G inputs. These func-  
tions control stages cool1, cool2, heat1, heat2, and indoor  
fan, respectively. If TSTAT function is NOT selected, the  
control determines the occupancy state on the Time Sched-  
ules or with remote occupied/unoccupied input. If tempera-  
ture compensated start is active, the unit will be controlled  
as in the Occupied mode. User-defined set points are shown  
in Table 18.  
The occupied or unoccupied comfort set points must be  
selected and the space temperature offset input will be used,  
if present. The Occupied Heat set point default value is  
68 F. The Occupied Cool set point default value is 78 F. The  
Unoccupied Heat set point default value is 55 F. The Un-  
occupied Cool set point value is 90 F. The control board will  
set appropriate operating mode and fan control. The control  
board will turn on indoor fan, if in Occupied mode, or de-  
termine if unit is in Unoccupied mode and the space tem-  
perature is outside of the unoccupied comfort set points,  
(Unoccupied Heat or Unoccupied Cool).  
The control board will then monitor space temperature against  
comfort set points and control heating or cooling stages as  
required. If system is in the Occupied mode, the economizer  
will operate as required. If the system is in Unoccupied  
mode, the system will perform nighttime free cool and IAQ  
(indoor air quality) pre-occupancy purge as required (when  
functions are enabled via software). Whenever the DX  
(di-rect expansion) cooling is requested, the outdoor fan will  
operate.  
The control board will operate economizer, run diagnos-  
tics to monitor alarms/alerts at all times, and respond to CCN  
communications to perform any configured network POC  
(product outboard control) functions such as time and outdoor-  
air temperature broadcast and Global occupancy broadcast.  
When the optional expansion I/O board is employed, it will:  
perform periodic scan and maintain database of expanded  
I/O points, perform Fire/Smoke control (power exhaust re-  
quired); and if in Occupied mode perform IAQ control and  
monitor fan, filter, demand limit, and field-applied status (with  
accessories).  
Return-Air Filters — Check that correct filters are in-  
stalled in filter tracks (see Table 1). Do not operate unit with-  
out return-air filters.  
Filter Replacement — To replace filters, open filter ac-  
cess door (marked with label). Remove inner access panel.  
Remove plastic filter retainer in between filter tracks by slid-  
ing and pulling outward. Remove first filter by sliding it out  
of the opening in filter track. Locate filter removal tool, which  
is shipped next to the return air dampers. Use the filter re-  
moval tool to remove the rest of the filters.  
Outdoor-Air Inlet Screens — Outdoor-air inlet screens  
must be in place before operating unit.  
EconomizerAdjustment — Remove filter access panel.  
Check that outdoor-air damper is closed and return-air damper  
is open.  
Economizer operation and adjustment are described in  
Sequence of Operation section on this page; and Minimum  
Damper Position Setting section on page 24.  
Gas Heat — Verify gas pressures before turning on heat  
as follows:  
1. Turn off field-supplied manual gas stop, located external  
to unit.  
2. Connect pressure gage to supply gas tap, located on field-  
supplied manual shutoff valve (see Fig. 13 on page 13).  
3. Connect pressure gage to manifold pressure tap on unit  
gas valve.  
4. Supply gas pressure must not exceed 13.5 in. wg. Check  
pressure at field-supplied shut-off valve.  
5. Turn on manual gas stop and initiate a heating demand.  
Jumper R to W1 in the control box to initiate heat. On  
VAV units, the RAT (Return-Air Temperature) must be  
less than or equal to 68 F for heating to be energized. Use  
the field test procedure to verify heat operation. After the  
unit has run for several minutes, verify that incoming pres-  
sure is 5.0 in. wg or greater, and that the manifold pres-  
sure is 3.5 in. wg. If manifold pressure must be adjusted,  
refer to Gas Valve Adjustment section on page 47.  
Sequence of Operation  
NOTE: Unit is shipped with default values that can be changed  
through Service Tool, Building Supervisor, or Comfort-  
Works™ software. See Table 18 for default values.  
COOLING, CONSTANT VOLUME (CV) UNITS — On  
power up, the control module will activate the initialization  
software of the control board. The initialization software then-  
reads DIP switch no. 1 position to determine CV or VAV  
operation. Next, DIP switch no. 2 is read to determine if the  
control is thermostat or sensor type operation. If switch 2 is  
If thermostats are used to energize the G input, the control  
will turn on indoor fan without delay and open economizer  
dampers to minimum position.  
39  
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Table 18 — User Defined Set Points  
SET POINT  
NAME  
FORMAT  
DESCRIPTION  
LIMITS  
DEFAULT  
OHSP  
OCSP  
UHSP  
UCSP  
SASP  
OATL  
NTLO  
RTIO  
LIMT  
xx.xF  
xx.xF  
xx.xF  
xx.xF  
xx.xF  
xx.xF  
xx.xF  
xx.x  
Occupied Heat Set Point  
Occupied Cool Set Point  
Unoccupied Heat Set Point  
Unoccupied Cool Set Point  
Supply Air Set Point  
55 to 80 F  
55 to 80 F  
40 to 80 F  
75 to 95 F  
45 to 70 F  
55 to 75 F  
40 to 70 F  
0 to 10  
68 F  
78 F  
55 F  
90 F  
55 F  
65 F  
50 F  
3
Hi OAT Lockout Temperature  
Unoccupied OAT Lockout Temperature  
Reset Ratio  
xx.xF  
xxx%  
Reset Limit  
0 to 20° F  
0 to 100%  
10%  
20%  
MDP  
Minimum Damper Position  
Low Temperature Minimum  
Damper Position Override  
LOWMDP  
xxx%  
0 to 100%  
100%  
IAQS  
UHDB  
UCDB  
LTMP  
HTMP  
PES1  
PES2  
xxxx  
IAQ Set Point  
1 to 5000 PPM  
0 to 10° F  
0 to 10° F  
0 to 100%  
0 to 100%  
0 to 100%  
0 to 100%  
650 PPM  
1° F  
xx.xF  
xx.xF  
xxx%  
xxx%  
xxx%  
xxx%  
Unoccupied Heating Deadband  
Unoccupied Cooling Deadband  
Low Temp. Min. Position  
1° F  
10%  
High Temp. Min. Position  
CV Power Exhaust Stage 1 Point  
CV Power Exhaust Stage 2 Point  
35%  
25%  
75%  
LEGEND  
CV  
IAQ  
OAT  
Constant Volume  
Indoor Air Quality  
Outdoor-Air Temperature  
If thermostats are used to deenergize the G input, the con-  
trol board will turn off indoor fan without any delay and close  
economizer dampers.  
of the control board. The initialization software then reads  
DIP switch no. 1 position to determine CV or VAV opera-  
tion. Initialization clears all alarms and alerts, re-maps the  
input/output database for VAV operation, sets maximum heat  
stages to 1 and sets maximum cool stages to 6. The control  
reads DIP switch no. 3 and if open, then it sets the internal  
flag for expansion mode operation.  
The control board will determine if an interface (linkage)  
is active and if the unit will operate in a Digital Air Volume  
(DAV) mode. In a DAV system, the room terminals are equipped  
with microprocessor controls that give commands to the base  
unit module. If an interface is active, the control will replace  
local comfort set points, space and return air temperatures  
and occupancy status with the linkage data supplied.  
When cooling, G must be energized before cooling can  
operate. The control board determines if outdoor conditions  
are suitable for economizer cooling using the standard out-  
door air thermistor. For economizer to function for free cool-  
ing, the enthalpy must be low, the outdoor air must equal to  
or less than the High Outdoor Air Temperature Lockout (de-  
fault is 65 F), the SAT (supply-air temperature) thermistor is  
NOT in alarm, and outdoor air reading is available. When  
these conditions are satisfied, the control board will use econo-  
mizer as the first stage of cooling.  
When Y1 input is energized, the economizer will be modu-  
lated to maintain SAT at the defined set point. The default is  
55 F. When SAT is above the set point, the economizer will  
be 100% open. When SAT is below the set point, the econo-  
mizer will modulate between minimum and 100% open po-  
sition. When Y2 is energized, the control will turn on com-  
pressor no. 1 and continue to modulate economizer as described  
above. If the Y2 remains energized and the SAT reading re-  
mains above the set point for 15 minutes, compressor no. 2  
will turn on. If Y2 is deenergized at any time, only the last  
stage of compression that was energized will be turned off.  
If outdoor conditions are not suitable for economizer cool-  
ing, the economizer will go to minimum position and cycle  
compressor no. 1 and 2 based on demand from Y1 and Y2  
respectively. The compressors will be locked out when the  
SAT temperature is too low (less than 40 F for compressor  
no. 1 and less than 45 F for compressor no. 2.) After a com-  
pressor is locked out, it can restart after normal time guard  
period.  
The Time Guardfunction maintains a minimum off time  
of 5 minutes, a minimum ON time of 10 seconds, and a  
minimum delay before starting the second compressor of  
10 seconds.  
When heating, the heat stages respond to the demand from  
W1 and W2 of the thermostat input. Heating and cooling  
will be mutually locked out on demand on a first call basis.  
The heating and the cooling functions cannot be operating  
simultaneously.  
The control board will determine occupancy status from  
Time Schedules (if programmed), Remote Occupied/  
Unoccupied input, global occupancy, or DAV. If tempera-  
ture compensated start is active, the unit will be controlled  
as in the Occupied mode.  
NOTE: The temperature compensated start is a period of time  
calculated to bring the unit on while unoccupied to reach the  
occupied set point when occupancy occurs.  
The control board will set the appropriate operating mode  
and fan control. The control board will turn VFD on if Oc-  
cupied mode is evident.  
For units equipped with a start/stop switch only (no space  
temperature sensor), if unoccupied and valid return-air tem-  
perature reading is available (either from a sensor or DAV),  
the control will monitor return-air temperature against Un-  
occupied Heat and Cool set points.  
For units with a start-stop switch and a space temperature  
sensor, the control board will start the VFD whenever SPT  
is outside of the set points (Unoccupied Heat or Unoccupied  
Cool). The VFD may also be started by nighttime thermostat  
via remote Occupied/Unoccupied input or by a temperature  
compensated start algorithm. When VFD is running in a nor-  
mal mode, the control will start heating or cooling as re-  
quired to maintain supply-air temperature at the supply air  
set point plus the reset (when enabled). The reset value is  
determined by SAT (supply-air temperature) reset and/or space  
temperature reset algorithms. The space temperature reset is  
only available when enabled through software.  
COOLING, VARIABLE VOLUME UNITS — On power up,  
the control module will activate the initialization software  
40  
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When cooling, the control will energize the power ex-  
haust enable output to the external power exhaust controller,  
when power exhaust is used.  
If occupied, the control will perform economizer control  
(economizer control same as described above for CV units).  
If unoccupied, the control will perform nighttime free cool  
and IAQ pre-occupancy purge as required (when enabled  
through software). When DX (direct expansion) cooling is  
called, the outdoor fans will always operate.  
The control will run continuous diagnostics for alarms/  
alerts; respond to CCN communications and perform any con-  
figured network POC (product outboard controls) functions  
such as time and outdoor-air temperature broadcast and glo-  
bal broadcast; and perform Fire/Smoke control if equipped  
with power exhaust.  
close. If the overtemperature limit opens after the indoor  
motor is stopped within 10 minutes of W1 becoming inac-  
tive, on the next cycle the time will be extended by 15 sec-  
onds. The maximum delay is 3 minutes. Once modified, the  
fan off delay will not change back to 45 seconds unless power  
is reset to the control. If the unit is controlled through a room  
sensor, the indoor fan will be operating in the Occupied mode  
and turned off after 45 seconds in the Unoccupied mode.  
GAS HEATING, VARIABLE AIR VOLUME (VAV) UNITS  
— All of the gas heating control is performed through the  
integrated gas control (IGC) board. The base module board  
serves only to initiate and terminate heating operation.  
NOTE: The unit is factory-configured for disabled occupied  
heating. DIP switch 5 is used to enable occupied heating (DIP  
switch 5 set to OPEN).  
GAS HEATING, CONSTANT VOLUME (CV) UNITS —  
The gas heat units incorporate 2 separate systems to provide  
gas heat. Each system incorporates its own induced-draft mo-  
tor, Integrated Gas Control (IGC) board, 2 stage gas valve,  
manifold, etc. The systems are operated in parallel; for ex-  
ample, when there is a call for first stage heat, both induced-  
draft motors operate, both gas valves are energized, and both  
IGC boards initiate spark.  
All of the gas heating control is performed through the  
IGC boards (located in the heating section). The base mod-  
ule board serves only to initiate and terminate heating  
operation.  
The base module board is powered by 24 vac. When the  
thermostat or room sensor calls for heating, power is sent  
from the base module board to W on each of the IGC boards.  
An LED on the IGC board will be on during normal opera-  
tion. A check is made to ensure that the rollout switches and  
limit switches are closed and the induced-draft motors are  
not running. The induced-draft motors are then energized,  
and when speed is proven with the hall effect sensor on the  
motor, the ignition activation period begins. The burners will  
ignite within 5 seconds.  
When ignition occurs the IGC board will continue to moni-  
tor the condition of the rollout and limit switches, the hall  
effect sensor, as well as the flame sensor. If the unit is con-  
trolled through a room thermostat set for fan auto., 45 sec-  
onds after ignition occurs, the indoor-fan motor will be  
energized and the outdoor-air dampers will open to their mini-  
mum position. If for some reason the overtemperature limit  
opens prior to the start of the indoor fan blower, on the next  
attempt, the 45-second delay will be shortened to 5 seconds  
less than the time from initiation of heat to when the limit  
tripped. Gas will not be interrupted to the burners and heat-  
ing will continue. Once modified, the fan on delay will not  
change back to 45 seconds unless power is reset to the con-  
trol. If the unit is controlled through a room sensor, the in-  
door fan will be operating in the Occupied mode and the  
outdoor-air dampers will be in the minimum position.  
The base module board is powered by 24 vac. When there  
is a call for heating (either Morning Warm-Up, Unoccupied,  
or Occupied modes), power is sent from the base module  
board to W on each of the IGC boards and W2 of the main  
gas valve. When heating, the control board will energize a  
field-supplied heat interlock relay output to drive the VAV  
terminal boxes wide open. The HIR is not required on a DAV  
system. See Fig. 42. In the Occupied mode the indoor-fan  
motor will be operating and the outdoor-air dampers will be  
in the minimum position. In the Unoccupied mode the indoor-  
fan motor will be off, but will energize 45 seconds after the  
call for heat and the outdoor-air dampers will move to the  
IAQ Unoccupied position (generally set to closed in the Un-  
occupied mode). The duct pressure sensor will signal to the  
variable frequency drive to operate at full speed since all  
terminals have been driven open. An LED on the IGC board  
will be on during normal operation. A check is made to en-  
sure that the rollout switches and limit switches are closed  
and the induced-draft motors are not running. The induced-  
draft motors are then energized and when speed is proven  
with the hall effect sensor on the motor, the ignition activa-  
tion period begins. The burners will ignite within 5 seconds.  
When ignition occurs the IGC board will continue to moni-  
tor the condition of the rollout and limit switches, the hall  
effect sensor, and the flame sensor.  
If the call for heat lasted less than 1 minute, the heating  
cycle will not terminate until 1 minute after heat became ac-  
tive. When heating is satisfied, the power will be interrupted  
to the IGC board and W1 and W2 of the main gas valve. If  
the unit is controlled through a room sensor, the indoor fan  
will be operating in the Occupied mode and turned off after  
45 seconds in the Unoccupied mode.  
MORNING WARM-UP (VAV only) (PC Accessed/CCN  
Operation) — Morning warm-up occurs when the control  
has been programmed to turn on heat prior to the Occupied  
mode to be ready for occupancy mode. Morning warm-up is  
a condition in VAV systems that occurs when the Tempera-  
ture Compensated Start algorithm calculates a biased occu-  
pied start time and the unit has a demand for heating. The  
warm-up will continue into the occupied period as long as  
there is a need for heat. During warm-up, the unit can con-  
tinue heating into the occupied period, even if occupied heat-  
ing is disabled. When the heating demand is satisfied, the  
warm-up condition will terminate. To increase or decrease  
the heating demand, use Service Tool software to change the  
Occupied Heating set point.  
NOTE: To utilize Morning Warm-Up mode, the unit occu-  
pancy schedule must be accessed via Service Tool, Building  
Supervisor, or ComfortWorks™ software or accessory LID-  
2B. The PC can access the base control board via the 3-wire  
communication bus or via an RJ-11 connection to the CCN  
terminal on the base control board. See Fig. 16.  
If the unit is controlled with a room sensor in the Unoc-  
cupied mode, the indoor fan will be energized through the  
IGC board with a 45-second delay and the outside-air damp-  
ers will move to the IAQ position (generally closed in the  
Unoccupied mode). If IAQ is not enabled, dampers will move  
to the minimum position.  
When additional heat is required, W2 closes and initiates  
power to the second stage of the main gas valves. When the  
thermostat is satisfied, W1 and W2 open and the gas valves  
close interrupting the flow of gas to the main burners. If the  
call for W1 lasted less than 1 minute, the heating cycle will  
not terminate until 1 minute after W1 became active. If the  
unit is controlled through a room thermostat set for fan auto.,  
the indoor-fan motor will continue to operate for an addi-  
tional 45 seconds then stop and the outdoor-air dampers will  
41  
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MORNING WARM-UP (VAV Only) (Stand-Alone Opera-  
tion) — When the unit operates in stand-alone mode, morn-  
ing warm-up occurs when the unit is energized in Occupied  
mode and return-air temperature (RAT) is below 68 F. Warm-up  
will not terminate until the RAT reaches 68 F. The heat in-  
terlock relay output is energized during morning warm-up.  
(A field-installed 24-vdc heat interlock relay is required.) The  
output will be energized until the morning warm-up cycle is  
complete. Refer to Fig. 42 for heat interlock relay wiring.  
in supply-air temperature per degree of space temperature  
change. A reset limit will exist which will limit the maxi-  
mum number of degrees the supply-air temperature may be  
raised. (Default is 10 F.) Both the reset ratio and the reset  
limit are user definable. The sequence of operation is as  
follows:  
1. The on/off status of the unit supply fan is determined.  
2. If the fan is ‘‘on,’’ the sequence will check if the system  
is occupied.  
SPACE TEMPERATURE RESET SENSOR (VAV Only) —  
An accessory space temperature sensor wired to terminals  
T1 and T2 on the control module is required. Space tem-  
perature reset is used to reset the supply-air temperature set  
point of a VAV system higher, as the space temperature falls  
below the Occupied Cool set point. As the space tempera-  
ture falls below the Occupied Cool set point, the supply-air  
temperature will be reset upward as a function of the reset  
ratio. (Default is 3.) Reset ratio is expressed in degrees change  
3. If the system is occupied, the sequence will determine if  
the reset option is enabled.  
4. If the reset option is enabled, the sequence will read the  
space temperature and compare it to the Occupied Cool  
set point. If the temperature is below the Occupied Cool  
set point, the algorithm will compute the reset value and  
compare this value against the reset limit. If it is greater  
than the reset limit, the sequence will use the reset limit  
as the reset value.  
TRAN2  
B
COM  
CB4  
3.2 AMPS  
SECONDARY  
24 VOLT  
LEGEND  
CB  
Circuit Breaker  
Common  
COM  
HIR  
T
Heat Interlock Relay  
Terminal  
BASE MODULE  
CONTROL BOARD  
TRAN  
Transformer  
COM  
INDOOR FAN RELAY  
T
30  
HIR  
T29  
FIELD  
INSTALLED  
T
28  
(HN61KK040)  
(24V, 9.5VA)  
Fig. 42 — Heat Interlock Relay Wiring  
mA INPUT  
DEG. F RESET  
BASE MODULE  
CONTROL BOARD  
4
5
0.00  
1.25  
6
2.50  
(+) T11  
(–) T12  
4-20 mA  
INPUT  
7
3.75  
8
5.00  
FIELD  
9
6.25  
SUPPLIED  
10  
11  
12  
13  
14  
15  
16  
17  
18  
19  
20  
7.50  
INPUT DEVICE  
8.75  
10.00  
11.25  
12.50  
13.75  
15.00  
16.25  
17.50  
18.75  
20.00  
LEGEND  
Terminal  
T
NOTE: The 4 to 20 mA input is a field-supplied non-  
Carrier EMS (Energy Management System) device.  
Fig. 43 — Space Temperature Reset Wiring  
42  
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Space Temperature Reset Example — The occupied cooling  
set point is set to 73 F. The Reset Ratio is set to 5. The Reset  
Limit is set to 20° F. The Reset Ratio determines how many  
degrees F the temperature is reset. At 72 F, the supply tem-  
perature will be reset 5 degrees higher. At 71 F, the supply  
temperature will be reset 10 degrees higher. At 70 F, the sup-  
ply temperature will be reset 15 degrees higher. At 69 F, the  
supply temperature will be reset 20 degrees higher and the  
Reset Limit will have been reached.  
SUPPLY AIR TEMPERATURE RESET — Supply air tem-  
perature reset is used to reset the supply air temperature util-  
ity. A 4 to 20 mA signal (field-supplied) is required. The re-  
set option does not require enabling.  
POWER EXHAUST OPERATION — The optional power  
exhaust packages are factory- or field-installed with vertical  
units and optionally installed in the return air ductwork for  
horizontal applications. The standard (offered with constant  
volume or variable air volume units) and the modulating power  
exhaust (offered on VAV units) are the two packages offered.  
The modulating power exhaust package is equipped with a  
field-adjustable static pressure controller to stage up to 4 power  
exhaust stages which will maintain a building static pres-  
sure. The blue controller located in the control box below  
the control board can be adjusted, by removing the covers  
and adjusting the set point dial to the desired building pres-  
sure. The blue controller monitors the 4 individual sequenc-  
ers which activate the 4 individual power exhaust motors.  
The standard power exhaust package controls up to 2 stages  
of power exhaust to maintain building pressure. The power  
exhaust package can be configured to deliver positive or nega-  
tive building pressure. These power exhaust stages are staged  
according to a percentage of the economizer dampers  
position. Default values are 25% for Stage 1 and 75% for  
Stage 2. This package has set points that are adjustable  
through software (Service Tool, Building Supervisor, or  
ComfortWorks™).  
Fig. 44 — Field-Supplied Smoke Detector Wiring  
as to specific smoke detector location due to liability  
considerations.  
INDOOR AIR QUALITY CONTROL — The accessory ex-  
pansion board and accessory IAQ sensor are required for IAQ  
control. The Carrier sensors operate with a 4 to 20 mA sig-  
nal. The 4 to 20 mA signal is connected to T11 (+) and T12  
(−) on the expansion board for the IAQ sensor, and T13 (+)  
and T14 (−) on the expansion board for the OAQ (Outdoor  
Air Quality) sensor. The sensor is field-mounted and wired  
to the expansion board installed in the unit main control box.  
The IAQ sensor must be powered by a field-supplied 24-v  
power supply (ungrounded). Do not use the unit 24-v power  
supply to power the sensor.  
Once installed, the sensor must be enabled. The sensor is  
configured with default values which may be changed through  
network access software. To work properly, the IAQ sensor  
high and low reference points for the sensor that is used must  
match the configured values. The expansion board reacts to  
a 4 to 20 mA signal from the IAQ sensor. The low reference  
(4 mA output) must be configured to the minimum IAQ sen-  
sor reading. The high reference (20 mA output) must be con-  
figured to the maximum IAQ sensor reading.  
SMOKE CONTROL MODES — The 48EJ,EK,EW,EY units  
with an optional expansion board perform fire and smoke  
control modes. The expansion board provides 4 modes which  
can be used to control smoke within the conditioned area.  
The modes of operation are fire shutdown, pressurization,  
evacuation, and smoke purge. See Table 19.  
The IAQ sensor can be configured to either low or high  
priority. The priority value can be changed by the user. The  
default is low.  
Low priority — When the priority is set to low, the initial  
control is to the IAQ set point, but the outside air damper  
position will change to its minimum position when the fol-  
lowing conditions occur:  
• CV units with sensor — when the space temperature is  
greater than the occupied cooling set point plus 2° F or  
when the space temperature is less than the occupied  
heating set point minus 2° F.  
VAV units and CV units with thermostat — when the  
supply-air temperature is less than the supply-air tem-  
perature set point minus 8° F or when the supply-air  
temperature is greater than the supply air temperature  
set point plus 5° F for 4 minutes.  
SMOKE DETECTOR — A smoke detector can be used to  
initiate fire shutdown. This can be accomplished by a set of  
normally closed pilot relay contacts which will interrupt power  
from the 24-v transformer, secondary ‘‘B’’ terminal to the  
control circuit breaker (CB4). See Fig. 44. The wire that con-  
nects these two points is white and labeled ‘‘W78.’’  
NOTE: On standard gas models, the indoor fan will con-  
tinue to run 45 seconds after the call for heat has been ter-  
minated. If fire shutdown is initiated the fan will stop im-  
mediately. No 45-second delay will occur.  
The smoke detector may be mounted in the return air duct  
or the supply duct. Carrier does not make recommendations  
Table 19 — Smoke Control Modes  
DEVICE  
Economizer  
PRESSURIZATION  
SMOKE PURGE  
EVACUATION  
100%  
OFF  
FIRE SHUTDOWN  
100%  
ON  
100%  
ON  
0%  
Indoor Fan/VFD  
Power Exhaust (all outputs)  
Heat Stages  
OFF  
OFF  
OFF  
OFF  
OFF  
OFF  
ON  
ON  
ON  
OFF  
ON  
OFF  
HIR  
OFF  
LEGEND  
HIR  
VFD  
Heat Interlock Relay  
Variable Frequency Drive  
43  
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• When the outdoor air quality is greater than the outdoor  
air quality set point (ppm)  
FIELD TEST — The field test program is initiated by mov-  
ing up DIP switch no. 4 to the OPEN position. The outdoor-  
air damper will close. The control allows 90 seconds for the  
damper to close in case it was in the full open position. Next,  
the indoor-fan contactor will be energized, and the outside-  
air damper will begin to open to its default value of 20% and  
stay at that position for a short period of time. The outdoor-  
air damper will then open to its full open position and stay  
at that position for a short period of time. The outdoor-air  
damper will then close.  
High priority — When the priority is set to high, the IAQ  
set point controls the outside air damper exclusively, with  
no regard to comfort conditioning.  
TIME GUARDCIRCUIT — The Time Guard function (built  
into the rooftop control board) maintains a minimum off time  
of 5 minutes, a minimum on time of 10 seconds, and a  
10-second delay between compressor starts.  
If the unit is equipped with power exhaust, stage 1 will be  
energized for 5 seconds. If the unit is configured for stage 2  
of power exhaust, stage 2 will be energized for 5 seconds  
after the first stage is deenergized.  
CRANKCASE HEATER — Unit main power supply must  
remain on to provide crankcase heater operation. The crank-  
case heater in each compressor keeps oil free of refrigerant  
while compressor is off.  
The first stage of heat will be energized for 30 seconds,  
after which the second stage heat will be energized for an  
additional 30 seconds. Heat is then deenergized.  
The last step is the Cooling mode. Outdoor-fan contactor  
no. 1 is energized. This is followed by each stage of cooling  
energized with a 10-second delay between stages. After this  
is complete, outdoor-fan contactor no. 2 is energized for  
10 seconds.  
The compressors will now deenergize, followed by the  
outdoor-fan contactors and indoor-fan contactors. If the unit  
is equipped with the Integrated Gas Control (IGC) board,  
the indoor fan will continue to operate for an additional  
30 seconds after deenergizing the circuit.  
HEAD PRESSURE CONTROL — Each unit has a fan cy-  
cling, outdoor thermostat to shut off the outdoor-fan mo-  
tor(s) at 55 F (one outdoor-fan motor on 024-034 units and  
two outdoor fan motors on 038-048 units). The head pres-  
sure control permits unit to operate with correct condensing  
temperatures down to 35 F outdoor-air temperature.  
MOTORMASTERIII CONTROL — The Motormaster  
III Solid-State Head Pressure Control is a field-installed ac-  
cessory fan speed control device actuated by a temperature  
sensor. It is specifically designed for use on Carrier equip-  
ment and controls the condenser-fan motor speed in re-  
sponse to the saturated condensing temperature. For outdoor  
temperatures down to −20 F, it maintains condensing tem-  
perature at 100 F. Refer to the accessory Motormaster in-  
stallation instructions for more information.  
The field test is then complete.  
SERVICE  
CAPACITY CONTROL, COOLING — The cooling capac-  
ity staging tables are shown in Tables 20 and 21.  
Before performing service or maintenance operations on  
unit, turn off main power switch to unit. Electrical shock  
could cause personal injury.  
Table 20 — Cooling Capacity Staging Table, CV Units  
with 2 Compressors  
Service Access — All unit components can be reached  
through clearly labelled hinged access doors. These doors  
are not equipped with tiebacks, so if heavy duty servicing is  
needed, either remove them or prop them open to prevent  
accidental closure.  
Stages  
1
0
2
3
Economizer  
Compressor 1  
Compressor 2  
off  
off  
off  
off  
on  
off  
on  
on  
Each door is held closed with 3 latches. The latches are  
secured to the unit with a single 14-in. - 20 x 12-in. long bolt.  
See Fig. 45.  
NOTE: On CV units that require additional unloading, add suction pres-  
sure unloaders to Compressor 1 only.  
Table 21 — Cooling Capacity Staging Table VAV Units  
with 2 Compressors and 2 Unloaders*  
Stages  
0
1
2
3
4
5
6
Compressor 1  
Unloader 1  
off  
off  
off  
off  
on  
on  
on  
off  
on  
on  
off  
off  
on  
off  
off  
off  
on  
on  
on  
on  
on  
on  
off  
on  
on  
off  
off  
on  
Unloader 2  
Compressor 2  
*40 ton units have only one unloader.  
Fig. 45 — Door Latch  
44  
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To open, loosen the latch bolt using a 716-in. wrench. Pivot  
the latch so it is not in contact with the door. Open the door.  
To shut, reverse the above procedure.  
NOTE: Disassembly of the top cover may be required under  
special service circumstances. It is very important that the  
orientation and position of the top cover be marked on the  
unit prior to disassembly. This will allow proper replace-  
ment of the top cover onto the unit and prevent rainwater  
from leaking into the unit.  
EVAPORATOR COIL — Remove access panels and clean  
as required with commercial coil cleaner.  
CONDENSER COIL — Clean condenser coil annually and  
as required by location and outdoor-air conditions. Inspect  
coil monthly; clean as required.  
CONDENSATE DRAIN — Check and clean each year at  
start of cooling season. In winter, keep drains and traps dry.  
FILTERS — Clean or replace at start of each heating and  
cooling season, or more often if operating conditions re-  
quire. Refer to Table 1 for type and size.  
IMPORTANT: After servicing is completed, make sure  
door is closed and relatched properly, and that the latches  
are tight. Failure to do so can result in water leakage  
into the evaporator section of the unit.  
NOTE: The unit requires industrial grade throwaway filters  
capable of withstanding face velocities up to 625 fpm.  
OUTDOOR-AIR INLET SCREENS — Clean screens with  
steam or hot water and a mild detergent. Do not use dis-  
posable filters in place of screens. See Fig. 24 for location of  
screens (filter track assembly).  
Cleaning — Inspect unit interior at beginning of each heat-  
ing and cooling season and as operating conditions require.  
Remove unit side panels and/or open doors for access to unit  
interior.  
MAIN BURNERS — At the beginning of each heating sea-  
son, inspect for deterioration or blockage due to corrosion or  
other causes. Observe the main burner flames and adjust if  
necessary. Check spark gap. See Fig. 46. Refer to Main Burn-  
ers section on page 48.  
Lubrication  
COMPRESSORS — Each compressor is charged with the  
correct amount of oil at the factory. The correct oil charge is  
shown in Table 1. If oil is visible in the compressor sight  
glass, check unit for operating readiness as described in Start-Up  
section, then start the unit. Observe oil level and add oil, if  
required, to bring oil level in compressor crankcase up to  
FLUE GAS PASSAGEWAYS — The flue collector box and  
heat exchanger cells may be inspected by removing gas sec-  
tion access panel (Fig. 3-6), flue box cover, collector box,  
and main burner assembly (Fig. 47 and 48). Refer to Main  
Burners section on page 48 for burner removal sequence. If  
cleaning is required, clean all parts with a wire brush. Re-  
assemble using new cerafelt high-temperature insulation for  
sealing.  
1
1
between ⁄4 and ⁄3 of sight glass during steady operation.  
If oil charge is above 13 sight glass, do not remove any oil  
until the compressor crankcase heater has been energized for  
at least 24 hours with compressor off.  
When additional oil or a complete charge is required, use  
only Carrier-approved compressor oil:  
Petroleum Specialties, Inc. . . . . . . . . . . . . . . . . . Cryol 150  
Texaco, Inc. . . . . . . . . . . . . . . . . . . . . . . . . . Capella WF-32  
Witco Chemical Corp. . . . . . . . . . . . . . . . . . . . Suniso 3GS  
COMBUSTION-AIR BLOWER — Clean periodically to as-  
sure proper airflow and heating efficiency. Inspect blower  
wheel every fall and periodically during heating season. For  
the first heating season, inspect blower wheel bi-monthly to  
determine proper cleaning frequency.  
To inspect blower wheel, remove heat exchanger access  
panel. Shine a flashlight into opening to inspect wheel. If  
cleaning is required, remove motor and wheel assembly by  
removing screws holding motor mounting plate to top of com-  
bustion fan housing (Fig. 47 and 48). The motor, scroll, and  
wheel assembly can be removed from the unit. Remove scroll  
from plate. Remove the blower wheel from the motor shaft  
and clean with a detergent or solvent. Replace motor and  
wheel assembly.  
IMPORTANT: Do not use reclaimed oil or oil that has  
been exposed to the atmosphere. Refer to Carrier Stand-  
ard Service Techniques Manual, Chapter 1, Refriger-  
ants section, for procedures to add or remove oil.  
FAN SHAFT BEARINGS — Lubricate bearings at least ev-  
ery 6 months with suitable bearing grease. Do not over grease.  
Typical lubricants are given below:  
MANUFACTURER  
Texaco  
LUBRICANT  
Regal AFB-2*  
Mobilplex EP No. 1  
Prestige 42  
Mobil  
Sunoco  
Texaco  
Multifak 2  
*Preferred lubricant because it contains rust and oxidation inhibitors.  
CONDENSER-AND EVAPORATOR-FAN MOTOR BEAR-  
INGS — The condenser- and evaporator-fan motors have  
permanently-sealed bearings, so no field lubrication is  
necessary.  
Fig. 46 — Spark Gap Adjustment  
45  
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NOTES:  
1. Torque set screws on blower wheel to 70 in. lbs ± 2 in. lbs.  
2. Torque set screw on propeller fan to 15 in. lbs ± 2 in. lbs.  
3. Dimensions are in inches.  
Fig. 47 — Typical Gas Heating Section  
3. Slide fan pulley along fan shaft.  
4. Make angular alignment by loosening motor from mount-  
ing plate.  
5. Retighten pulley.  
Evaporator Fan Service and Replacement  
1. Shut off unit power supply.  
2. Remove supply-air section panels.  
3. Remove belt and blower pulley.  
4. Loosen setscrews in blower wheels.  
5. Remove locking collars from bearings.  
6. Remove shaft.  
7. Remove venturi on opposite side of bearing.  
8. Lift out wheel.  
9. Reverse above procedure to reinstall fan.  
10. Check and adjust belt tension as necessary.  
Fig. 48 — Gas Heat Section Details  
Belt Tension Adjustment — To adjust belt tension:  
1. Shut off unit power supply.  
Evaporator Fan Performance Adjustment  
(Fig. 49) — Fan motor pulleys are designed for speed shown  
in Table 1 (factory speed setting).  
2. Loosen motor mounting nuts and bolts. See Fig. 50.  
3. Loosen fan motor nuts.  
4. Turn motor jacking bolts to move motor mounting plate  
left or right for proper belt tension. A slight bow should  
be present in the belt on the slack side of the drive while  
running under full load.  
IMPORTANT: Check to ensure that the unit drive  
matches the duct static pressure using Tables 12-14.  
To change fan speeds, change pulleys.  
To align fan and motor pulleys:  
1. Shut off unit power supply.  
5. Tighten nuts.  
6. Adjust bolts and nut on mounting plate to secure motor  
in fixed position. Recheck belt tension after 24 hours of  
operation. Adjust as necessary.  
2. Loosen fan shaft pulley bushing.  
46  
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Evaporator-Fan Motor Replacement  
1. Shut off unit power supply.  
2. Remove upper outside panel and open hinged door to  
gain access to motor.  
3. Fully retract motor plate adjusting bolts.  
4. Loosen the two rear (nearest the evaporator coil) motor  
plate nuts.  
5. Remove the two front motor plate nuts and carriage bolts.  
6. Slide motor plate to the rear (toward the coil) and re-  
move fan belt(s).  
7. Slide motor plate to the front and hand tighten one of  
the rear motor plate nuts (tight enough to prevent the  
motor plate from sliding back but loose enough to allow  
the plate to pivot upward).  
8. Pivot the front of the motor plate upward enough to al-  
low access to the motor mounting hex bolts and secure  
in place by inserting a prop.  
9. Remove the nuts from the motor mounting hex bolts and  
remove motor.  
10. Reverse above steps to install new motor.  
Condenser-Fan Adjustment  
1. Shut off unit power supply.  
2. Remove fan guard.  
3. Loosen fan hub setscrews.  
4. Adjust fan height on shaft using a straightedge placed across  
venturi and measure per Fig. 51.  
Fig. 49 — Evaporator-Fan Alignment and  
Adjustment  
5. Fill hub recess with permagum if rubber hubcap is  
missing.  
6. Tighten setscrews and replace panel(s).  
7. Turn on unit power.  
Thermostatic Expansion Valve (TXV) — Each cir-  
cuit has a TXV. The TXV is nonadjustable and is factory set  
to maintain 10 to 13° F superheat leaving the evaporator coil.  
The TXV controls flow of liquid refrigerant to the evapo-  
rator coils.  
Power Failure — The economizer damper motor is a  
spring return design. In event of power failure, dampers will  
return to fully closed position until power is restored.  
Gas Valve Adjustment  
Refrigerant Charge — Amount of refrigerant charge  
is listed on unit nameplate and in Table 1. Refer to Carrier  
GTAC II; Module 5; Charging, Recovery, Recycling, and  
Reclamation section for charging methods and procedures.  
Unit panels must be in place when unit is operating dur-  
ing charging procedure.  
NATURAL GAS — The 2-stage gas valve opens and closes  
in response to the thermostat or limit control.  
When power is supplied to valve terminals 3 and 4, the  
pilot valve opens to the preset position. When power is sup-  
plied to terminals 1 and 2, the main valve opens to its preset  
position.  
NOTE: Do not use recycled refrigerant as it may contain  
contaminants.  
The regular factory setting is stamped on the valve body  
(3.5 in. wg).  
NO CHARGE — Use standard evacuating techniques. After  
evacuating system, weigh in the specified amount of  
refrigerant (refer to Table 1).  
To adjust regulator:  
1. Set thermostat at setting for no call for heat.  
2. Turn main gas valve to OFF position.  
LOW CHARGE COOLING — Using appropriate cooling  
charging chart (see Fig. 52 and 53), add or remove refrig-  
erant until conditions of the appropriate chart are met. Note  
that charging chart is different from those normally used. An  
accurate pressure gage and temperature sensing device are  
required. Measure liquid line pressure at the liquid line serv-  
ice valve using pressure gage. Connect temperature sensing  
device to the liquid line near the liquid line service valve  
and insulate it so that outdoor ambient temperature does not  
affect reading.  
1
3. Remove 8-in. pipe plug from manifold. Install a water  
manometer pressure-measuring device.  
4. Set main gas valve to ON position.  
5. Set thermostat at setting to call for heat.  
6. Remove screw cap covering regulator adjustment screw  
(See Fig. 54).  
7. Turn adjustment screw clockwise to increase pressure or  
counterclockwise to decrease pressure.  
8. Once desired pressure is established, set thermostat set-  
ting for no call for heat, turn off main gas valve, remove  
Using the above temperature and pressure readings, find  
the intersect point on the appropriate cooling charging chart.  
If intersection point on chart is above line, add refrigerant.  
If intersection point on chart is below line, carefully reclaim  
some of the charge. Recheck suction pressure as charge is  
adjusted.  
1
pressure-measuring device and replace 8-in. pipe plug  
and screw cap.  
NOTE: Indoor-air cfm must be within normal operating range  
of unit. All outdoor fans must be operating.  
47  
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Fig. 50 — Belt Tension Adjustment  
Fig. 53 — Cooling Charging Chart,  
48EJ,EK,EW,EY038-048  
Fig. 51 — Condenser-Fan Adjustment  
Main Burners — For all applications, main burners are  
factory set and should require no adjustment.  
MAIN BURNER REMOVAL (Fig. 55)  
1. Shut off (field-supplied) manual main gas valve.  
2. Shut off power to unit.  
3. Remove heating access panel.  
4. Disconnect gas piping from gas valve inlet.  
5. Remove wires from gas valve.  
6. Remove wires from rollout switch.  
7. Remove sensor wire and ignitor cable from IGC board.  
8. Remove 2 screws securing manifold bracket to basepan.  
9. Remove 4 screws that hold the burner support plate flange  
to the vestibule plate.  
10. Lift burner assembly out of unit.  
11. Reverse procedure to re-install burners.  
Filter Drier — Replace whenever refrigerant system is  
exposed to atmosphere.  
Protective Devices  
COMPRESSOR PROTECTION  
Overcurrent — Each compressor has one manual reset, cali-  
brated trip, magnetic circuit breaker. Do not bypass connec-  
tions or increase the size of the circuit breaker to correct trouble.  
Determine the cause and correct it before resetting the breaker.  
Overtemperature — Each 06D type compressor (024-038 units)  
has an internal protector to protect it against excessively high  
discharge gas temperatures.  
Fig. 52 — Cooling Charging Chart,  
48EJ,EK,EW,EY024-034  
48  
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Crankcase Heater — Each compressor has a crankcase heater  
to prevent absorption of liquid refrigerant by oil in the crank-  
case when the compressor is idle. Since power for the crank-  
case heaters is drawn from the unit incoming power, main  
unit power must be on for the heaters to be energized.  
Compressor Lockout Logic — If any of the safe-  
ties trip, the circuit will automatically reset (providing the  
safety has reset) and restart the compressor in 15 minutes. If  
any of the safeties trip 3 times within a 90-minute period,  
then the circuit will be locked out and will require manual  
resetting by turning off either the unit disconnect or the con-  
trol circuit breaker, or opening the thermostat.  
IMPORTANT: After a prolonged shutdown or serv-  
ice job, energize the crankcase heaters for 24 hours  
before starting the compressors.  
Replacement Parts — A complete list of replacement  
parts may be obtained from any Carrier distributor upon  
request.  
EVAPORATOR FAN MOTOR PROTECTION — A manual  
reset, calibrated trip, magnetic circuit breaker protects against  
overcurrent. Do not bypass connections or increase the size  
of the breaker to correct trouble. Determine the cause and  
correct it before resetting the breaker. If the evaporator-fan  
motor is replaced with a different horsepower motor, resiz-  
ing of the circuit breaker is required. Contact Carrier  
Application Engineering.  
CONDENSER-FAN MOTOR PROTECTION — Each  
condenser-fan motor is internally protected against  
overtemperature.  
HIGH- AND LOW-PRESSURE SWITCHES — If either  
switch trips, or if the compressor overtemperature switch ac-  
tivates, that refrigerant circuit will be automatically stopped.  
See Compressor Lockout Logic section on this page.  
FREEZE PROTECTION THERMOSTAT (FPT) — Freeze  
protection thermostats are located on the evaporator coil for  
each circuit. One is located at the top and bottom of each  
circuit. It detects frost build-up and turns off the compressor,  
allowing the coil to clear. Once the frost has melted, the com-  
pressor can be reenergized.  
Fig. 54 — Gas Valve  
Relief Devices — All units have relief devices to pro-  
tect against damage from excessive pressures (i.e., fire). These  
devices are installed on the suction line, liquid line, and on  
the compressor.  
Power Circuit — A typical power wiring schematic is  
shown in Fig. 56.  
Control Circuit, 115-V — This control circuit is pro-  
tected against overcurrent by a 5.0 amp circuit breaker (CB3).  
Breaker can be reset. If it trips, determine cause of trouble  
before resetting. A typical 115-v control wiring schematic is  
shown in Fig. 57 and 58.  
Control Circuit, 24-V — This control circuit is pro-  
tected against overcurrent by a 3.2 amp circuit breaker (CB4).  
Breaker can be reset. If it trips, determine cause of trouble  
before resetting. A typical 24-v control wiring schematic is  
shown in Fig. 59 and 60.  
Fig. 55 — Main Burner Removal  
49  
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LEGEND and NOTES for Fig. 56-60 — Typical Wiring Schematics  
LEGEND  
AHA  
BP  
Adjustable Heat Anticipator  
Building Pressure  
Burner Relay  
IFC  
Indoor Fan Contactor  
Indoor Fan Circuit Breaker  
Indoor-Fan Motor  
Indoor-Fan Relay  
Integrated Gas Unit Controller  
Internal Protector  
Light  
TC  
Thermostat Cooling  
Thermostat Heating  
Transformer  
IFCB  
IFM  
IFR  
TH  
BR  
TRAN  
UL  
VFD  
C
Contactor, Compressor  
Capacitor  
Compressor Unloader  
Variable Frequency Drive  
CAP  
CB  
IGC  
IP  
L
Circuit Breaker  
Terminal (Marked)  
CC  
Cooling Compensator  
Controller Circuit Breaker  
Crankcase Heater  
Communication  
Compressor Motor  
Control Relay  
CCB  
CCH  
COM  
COMP  
CR  
LPS  
MGV  
NC  
Low-Pressure Switch  
Main Gas Valve  
Terminal (Unmarked)  
Normally Closed  
Normally Open  
NO  
Terminal Block  
OAT  
OFC  
OFM  
PEC  
PEM  
PES  
Outdoor-Air Thermistor  
Outdoor-Fan Contactor  
Outdoor-Fan Motor  
Power Exhaust Contactor  
Power Exhaust Motor  
Power Exhaust Sequencer  
Power Exhaust Sequencer  
Controller  
DM  
Damper Motor  
Duct Pressure  
Splice  
DP  
EC  
Enthalpy Control  
Equipment  
Factory Wiring  
Field Wiring  
EQUIP  
FLA  
FPT  
FU  
Full Load Amps  
Freeze Protection Thermostat PESC  
Fuse  
Ground  
To Indicate Common Potential Only,  
Not To Represent Wiring  
GRD  
GVR  
HPS  
HS  
HV  
IDM  
PL  
R
RAT  
RS  
SAT  
TB  
Plug Assembly  
Relay  
Gas Valve Relay  
High-Pressure Switch  
Hall Effect Sensor  
High Voltage  
Return-Air Thermistor  
Rollout Switch  
Supply-Air Thermistor  
Terminal Block  
Induced-Draft Motor  
NOTES:  
1. Connect TRAN1 to H4 for 460 v units. Connect to H3 for 230 v. If  
208/230 v units are run with a 208 v power supply connect to H2.  
2. Connect TRAN2 to black lead for 460 v units. Connect to orange  
lead for 230 v units. If 208/230 v units are run with a 208 v power  
supply connect to red lead.  
3. Circuit breaker must trip amps are equal to or less than 156% FLA  
for CB1 and CB2. All others are 140%.  
4. If any of the original wire furnished must be replaced, it must be  
replaced with type 90 C wire or its equivalent.  
5. Compressors and/or fan motors are thermally protected.  
6. Three phase motors are protected against primary single phasing  
conditions.  
7. Red wire and violet wire are spliced together at the factory. The  
brown wire has a wire nut added at the factory.  
TABLE A  
TABLE B  
THE FOLLOWING COMPRESSORS HAVE  
TWO PARALLEL WIRES RUN FROM TB1  
TO THE COMPRESSORS  
THE FOLLOWING FAN MOTORS HAVE TWO  
PARALLEL WIRES RUN FROM TB1 TO THE  
FAN MOTORS  
(NOT SHOWN ON LABEL DIAGRAM)  
(NOT SHOWN ON LABEL DIAGRAM)  
COMPRESSOR  
MODEL  
WIRE  
QUANTITY  
INDOOR  
MOTOR  
WIRE  
QUANTITY  
VOLTAGE  
VOLTAGE  
06D-537  
208/230-3-60  
2
20 HP  
208/230-3-60  
2
50  
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Fig. 56 — Typical Power Schematic; 48EJ,EK,EW,EY024-034; 208/230-3-60 and 460-3-60  
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Fig. 57 — Typical VAV 115-v Control Circuit  
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Fig. 58 — Typical CV 115-v Control Circuit  
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Fig. 59 — Typical VAV 24-v Control Circuit  
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Fig. 60 — Typical CV 24-v Control Circuit  
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TROUBLESHOOTING  
Typical refrigerant circuiting diagrams are shown in Fig. 61-63. An algorithm diagram of the IGC (Integrated Gas Unit Con-  
troller) control is shown in Fig. 64.  
LEGEND  
FPS  
HPS  
LPS  
Freeze Protection Switch  
High-Pressure Switch  
Low-Pressure Switch  
Fig. 61 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY024-034)  
56  
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LEGEND  
FPS  
HPS  
LPS  
Freeze Protection Switch  
High-Pressure Switch  
Low-Pressure Switch  
Fig. 62 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY038,044)  
57  
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LEGEND  
FPS  
HPS  
LPS  
Freeze Protection Switch  
High-Pressure Switch  
Low-Pressure Switch  
Fig. 63 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY048)  
58  
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LEGEND  
IDM  
IGC  
Induced-Draft Motor  
Integrated Gas Unit Controller  
NOTE: Thermostat Fan Switch in the ‘‘AUTO’’ position or sensor-equipped unit.  
Fig. 64 — IGC Control (Heating and Cooling)  
59  
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The alarm codes for the IGC control board are shown in  
Table 22.  
Diagnostic LEDs — There are 3 LEDs (red, yellow,  
and green) on the lower right hand side of the control board.  
The red light is used to check unit operation and alarms. A  
constant pulse is normal unit operation. A series of quick  
blinks indicates an alarm. Refer to Table 23 below for a de-  
scription of alarms. The yellow LED blinks during transmis-  
sion with the CCN (Carrier Comfort Network). The green  
LED blinks during transmission with the expansion board.  
Table 22 — IGC Control Board LED Alarms  
INDICATION  
ON  
ERROR MODE  
Normal Operation  
OFF  
Hardware Failure  
1 FLASH  
Fan ON/OFF Delay Modified  
Limit Switch Fault  
2 FLASHES  
3 FLASHES  
4 FLASHES  
5 FLASHES  
6 FLASHES  
7 FLASHES  
8 FLASHES  
Flame Sense Fault  
4 Consecutive Limit Switch Faults  
Ignition Lockout Fault  
Induced Draft Motor Fault  
Rollout Switch Fault  
Internal Control Fault  
Table 23 — Control Board LED Alarms  
LED Blinks  
1
Error Code  
Description  
Troubleshooting Comments  
The expansion board and control board flash the red LED in one-second  
intervals when the board is operating properly.  
Normal Operation  
The high or low pressure safety switch for compressor no. 1 has opened for  
3 seconds. The error will be cleared and compressor no. 1 will be allowed  
to turn on in 15 minutes. If the safeties have been tripped 3 times in 90 min-  
utes, compressor no. 1 will be locked out until the control board has been  
manually reset.  
2
3
HF-13  
Compressor 1 Safety  
Compressor 2 Safety  
The high or low pressure safety switch for compressor no. 2 has opened for  
3 seconds. The error will be cleared and compressor no. 2 will be allowed  
to turn on in 15 minutes. If the safeties have been tripped 3 times in 90 min-  
utes, compressor no. 2 will be locked out until the control board has been  
manually reset.  
HF-14  
The thermostat is calling for both heating and cooling at the same time. The  
unit will operate on a first call basis and will automatically reset.  
4
5
6
7
HF-15  
HF-05  
HF-06  
HF-03  
Thermostat Failure  
The supply-air temperature (SAT) sensor has failed. First check for wiring  
errors, then replace sensor.  
SAT Thermistor Failure  
OAT Thermistor Failure  
Space Temp. Sen. Failure  
The outside air temperature (OAT) sensor has failed. First check for wiring  
errors, then replace sensor.  
The space temperature sensor has failed. First check for wiring errors, then  
replace sensor.  
The return-air temperature (RAT) sensor has failed. Ensure that the unit is  
a VAV unit. If NOT a VAV unit set DIP switch position 1 to the closed position  
and reset power. Then check for wiring errors. Finally, replace sensor.  
8
9
HF-12  
SE-05  
RAT Thermistor Failure  
Communications between the expansion board and the control board have  
been interrupted. Ensure that an expansion board is installed and wired us-  
ing the wire harness supplied with the expansion module. If an expansion  
board is not used ensure that DIP switch position 3 is in the closed position,  
and reset power.  
Loss of Communications  
with Expansion Board  
Generated when hardware has failed on control board. Replace the control  
board.  
10  
11  
HF-16  
HF-17  
Control Board Failure  
Generated when hardware has failed on the expansion board. Replace the  
expansion board.  
Expansion Board Failure  
DIP  
VAV  
Dual In-Line Package  
Variable Air Volume  
60  
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Tables 24-26 show the input and output channel  
designations.  
Table 24 — I/O Channel Designations Base Module — CV  
TERMINAL NO.  
T1-2  
ASSIGNMENT  
SPT (CCN) — 10KThermistor  
STO (CCN) — 10KThermistor  
OAT — 5KThermistor  
SAT — 5KThermistor  
TERMINAL NO.  
T23-25  
T24-25  
T26-27  
T28-29  
T30-29  
T31-32  
T33-32  
T34-35  
T36-35  
T37-38  
T39-38  
K1  
ASSIGNMENT  
Compressor 2 Safety — DI (24 vac)  
T3-4  
Outside Air Enthalpy — DI (24 vac)  
Economizer Pos. — AO (4-20 mA)  
Heat 1 Relay — DO (24 vac)  
Heat 2 Relay — DO (24 vac)  
CV Power Exhaust 1/Modulating Power Exhaust — DO (115 vac)  
CV Power Exhaust 2 — DO (115 vac)  
Condenser Fan — DO (115 vac)  
OFC2 — DO (115 vac)  
T5-6  
T7-8  
T9-10  
T11-12  
T13-14  
T15-16  
T17-25  
T18-25  
T19-25  
T20-25  
T21-25  
T22-25  
SAT Reset — AI (4 to 20 mA)  
Y1 or Remote Start/Stop — DI (24 vac)  
Y2 — DI (24 vac)  
W1 — DI (24 vac)  
W2 — DI (24 vac)  
Indoor Fan Relay — DO (LV)  
Compr. 1 — DO (HV)  
G — DI (24 vac)  
K2  
Compressor 1 Safety — DI (24 vac)  
K3  
Compr. 2 — DO (HV)  
Table 25 — I/O Channel Designations Base Module — VAV  
TERMINAL NO.  
T1-2  
ASSIGNMENT  
TERMINAL NO.  
T23-25  
T24-25  
T26-27  
T28-29  
T30-29  
T31-32  
T33-32  
T34-35  
T36-35  
T37-38  
T39-38  
K1  
ASSIGNMENT  
Compressor 2 Safety — DI (24 vac)  
Outside Air Enthalpy — DI (24 vac)  
Economizer Pos. — AO (4-20 mA)  
Heat 1 Relay − DO (24 vac)  
Heat Interlock Relay — DO (24 vac)  
Modulated Power Exhaust — DO (115 vac)  
SPT (CCN) — 10KThermistor  
T3-4  
RAT — 5KThermistor  
T5-6  
OAT — 5KThermistor  
T7-8  
SAT — 5KThermistor  
T9-10  
T11-12  
T13-14  
T15-16  
T17-25  
T18-25  
T19-25  
T20-25  
T21-25  
T22-25  
SAT Reset — AI (4 to 20 mA)  
Condenser Fan — DO (115 vac)  
OFC2 — DO (115 vac)  
Remote Start/Stop — DI (24 vac)  
Unloader 1 — DO (115 vac)  
Unloader 2 — DO (115 vac)  
Indoor Fan Relay — DO (LV)  
Compr. 1 (HV)  
K2  
Compressor 1 Safety — DI (24 vac)  
K3  
Compr. 2 — DO (HV)  
Table 26 — I/O Channel Designations Expansion Module (Field-Installed) — CV and VAV  
TERMINAL NO.  
T1-2  
ASSIGNMENT  
TERMINAL NO.  
T23-25  
T24-25  
T26-27  
T28-29  
T30-29  
T31-32  
T33-32  
T34-35  
T36-35  
T37-38  
T39-38  
K1  
ASSIGNMENT  
Fire — Evacuation — DI (24 vac)  
T3-4  
Fire — Smoke Purge — DI (24 vac)  
T5-6  
T7-8  
T9-10  
Alarm Light Indicator — DO (24 vac)  
T11-12  
T13-14  
T15-16  
T17-25  
T18-25  
T19-25  
T20-25  
T21-25  
T22-25  
IAQ Indoor — AI (4 to 20 mA)  
IAQ Outdoor — AI (4 to 20 mA)  
Power Exhaust Fire No. 1 — DO (115 vac)  
Power Exhaust Fire No. 2 — DO (115 vac)  
Power Exhaust Fire No. 3 — DO (115 vac)  
Fan Status — DI (24 vac)  
Filter Status − DI (24 vac)  
Field Applied Status — DI (24 vac)  
Demand Limit — DI (24 vac)  
Fire — Unit Shutdown — DI (24 vac)  
Fire — Pressurization — DI (24 vac)  
Power Exhaust Fire No. 4 — DO (115 vac)  
K2  
K3  
LEGEND (Tables 24-26)  
K⍀  
Kilo-Ohms  
AI  
Analog Input  
LV  
Low Voltage  
AO  
CCN  
CV  
DI  
Analog Output  
OAT  
OFC  
RAT  
SAT  
SPT  
STO  
T
Outdoor-Air Temperature  
Outdoor Fan Contactor  
Return-Air Temperature  
Supply-Air Temperature  
Space Temperature  
Space Temperature Offset  
Terminal  
Carrier Comfort Network  
Constant Volume  
Direct Input  
DO  
HV  
IAQ  
Direct Output  
High Voltage  
Indoor Air Quality  
VAV  
Variable Air Volume  
NOTE: For 4 to 20 mA signals, all even numbered terminals are negative (−) polarity, and all odd numbered terminals are positive (+) polarity.  
61  
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PACKAGED SERVICE TRAINING  
Our packaged service training programs provide an excellent way to increase your knowledge of the  
equipment discussed in this manual. Product programs cover:  
• Unit Familiarization  
• Installation Overview  
• Maintenance  
• Operating Sequence  
A large selection of product, theory, and skills programs is available. All programs include a video  
cassette and/or slides and a companion booklet. Use these for self teaching or to conduct full training  
sessions.  
For a free Service Training Material Catalog (STM), call 1-800-962-9212. Ordering instructions are  
included.  
Copyright 1997 Carrier Corporation  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
Book 1  
PC 111  
Catalog No. 564-962  
Printed in U.S.A.  
Form 48E-5SI  
Pg 62  
8-97  
Replaces: 48E-3SI  
Tab 1a  
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START-UP CHECKLIST  
MODEL NO.:  
SERIAL NO.:  
SOFTWARE VERSION (SEE FIG. 16)  
DATE:  
TECHNICIAN:  
PRE-START-UP:  
VERIFY THAT DIP SWITCH SETTINGS ARE CORRECT  
VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT  
REMOVE ALL SHIPPING HOLDDOWN BOLTS AND BRACKETS PER INSTRUCTIONS  
VERIFY INSTALLATION OF ECONOMIZER HOOD  
VERIFY INSTALLATION OF ALL OPTIONS AND ACCESSORIES  
VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS  
VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT  
CHECK GAS PIPING FOR LEAKS  
CHECK THAT INDOOR-AIR FILTERS ARE CLEAN AND IN PLACE  
VERIFY THAT UNIT IS LEVEL WITHIN TOLERANCES  
CHECK FAN WHEELS AND PROPELLERS FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SETSCREW  
IS TIGHT  
VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED  
VERIFY THAT SUCTION, DISCHARGE, AND LIQUID SERVICE VALVES ON EACH CIRCUIT ARE OPEN  
START-UP  
ELECTRICAL  
SUPPLY VOLTAGE L1-L2  
L2-L3  
L3-L1  
COMPRESSOR AMPS — COMPRESSOR NO. 1 L1  
— COMPRESSOR NO. 2 L1  
L2  
L2  
L3  
L3  
SUPPLY FAN AMPS (CV)  
(VAV)  
EXHAUST FAN AMPS  
*
*VAV fan supply amps reading must be taken with a true RMS meter for accurate readings.  
ADJUST VARIABLE FREQUENCY DRIVE (VFD) TO APPLICATION REQUIREMENTS.  
TEMPERATURES  
OUTDOOR-AIR TEMPERATURE  
RETURN-AIR TEMPERATURE  
COOLING SUPPLY AIR  
F DB (Dry Bulb)  
F DB  
F
WB (Wet Bulb)  
F
F
GAS HEAT SUPPLY AIR  
PRESSURES  
GAS INLET PRESSURE  
GAS MANIFOLD PRESSURE  
REFRIGERANT SUCTION  
REFRIGERANT DISCHARGE  
IN. WG  
IN. WG  
PSIG  
STAGE NO. 1  
CIRCUIT NO. 1  
CIRCUIT NO. 1  
STAGE NO. 2  
CIRCUIT NO. 2  
CIRCUIT NO. 2  
IN. WG  
PSIG  
PSIG  
PSIG  
VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS ON PAGE 48  
CL-1  
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GENERAL  
SET ECONOMIZER MINIMUM VENT POSITION TO JOB REQUIREMENTS  
ENSURE DRIVES OPERATE WITHIN LIMITS OF FAN PERFORMANCE TABLES  
HIGH PRESSURE SWITCH SETTING  
LOW PRESSURE SWITCH SETTING  
MOTOR PULLEY PART NUMBER  
FAN PULLEY PART NUMBER  
BELT PART NUMBER  
psig  
psig  
BELT SIZE  
in.  
in.  
FILTER QUANTITY  
FILTER SIZES  
ADDITIONAL NOTES:  
_______________________________________________________________________________________________________  
_______________________________________________________________________________________________________  
_______________________________________________________________________________________________________  
_______________________________________________________________________________________________________  
_______________________________________________________________________________________________________  
_______________________________________________________________________________________________________  
Copyright 1997 Carrier Corporation  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
Book 1  
PC 111  
Catalog No. 564-962  
Printed in U.S.A.  
Form 48E-5SI  
Pg CL-2  
8-97  
Replaces: 48E-3SI  
Tab 1a  
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