Carrier 50Ej Users Manual

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50EJ,EK,EW,EY024-048
Single-Package Rooftop Units
Electric Cooling with Electric Heat Option

Installation, Start-Up and
Service Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-31
Step 1 — Provide Unit Support . . . . . . . . . . . . . . 1
• ROOF CURB
• ALTERNATE UNIT SUPPORT
Step 2 — Rig and Place Unit . . . . . . . . . . . . . . . . . 8
• POSITIONING
• ROOF MOUNT
Step 3 — Field Fabricate Ductwork . . . . . . . . . . . 11
Step 4 — Make Unit Duct Connections . . . . . . . 11
Step 5 — Trap Condensate Drain . . . . . . . . . . . . . 11
Step 6 — Controls Options . . . . . . . . . . . . . . . . . . 12
• CONSTANT VOLUME APPLICATIONS
• VARIABLE AIR VOLUME (VAV)
APPLICATIONS
Step 7 — Make Electrical Connections . . . . . . . 15
• POWER WIRING
• FIELD POWER SUPPLY
• FIELD CONTROL WIRING
Step 8 — Make Outdoor-Air Inlet
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
• ECONOMIZER
• ECONOMIZER SETTINGS
Step 9 — Position Power Exhaust/
Barometric Relief Damper Hood . . . . . . . . . . . . . 29
Step 10 — Install Accessories . . . . . . . . . . . . . . . 30
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32-42
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42-45
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . 46-51
START-UP CHECKLIST . . . . . . . . . . . . . . . CL-1, CL-2

SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment
can be hazardous due to system pressure and electrical components. Only trained and qualified service personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform 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, observe precautions in the literature, tags and labels attached
to the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire extinguishers available for all brazing operations.

IMPORTANT — READ BEFORE INSTALLING
IMPORTANT: Due to upgrades in unit control software and hardware, units produced currently are slightly
different than original design units. The unit control
software (which has changed) is designated with a sticker
on the unit control board, chip U8 (the large chip in
the center of the board), which states the software Version number. Version 1.0 is the original version. Version 2.0 is the current version. Differences in installation, configuration, and start-up procedures in this
manual will be identified by Version number.

INSTALLATION
Step 1 — Provide Unit Support
All panels must be in place when rigging. Unit is not
designed for handling by fork truck.
ROOF CURB — Assemble and install accessory roof curb
in accordance with instructions shipped with the curb. Accessory roof curb and information required to field fabricate
a roof curb or horizontal adapter are shown in Fig. 1 and 2.
Install insulation, cant strips, roofing, and counter flashing
as shown. Ductwork can be secured to roof curb before unit
is set in place.
IMPORTANT: The gasketing of the unit to the roof
curb is critical for a leak-proof seal. Install gasket supplied with the roof curb as shown in Fig. 1. Improperly applied gasket can result in air leaks and poor unit
performance.
Curb should be level. This is necessary to permit unit drain
to function properly. Unit leveling tolerance is shown in
Fig 1 and 2. Refer to Accessory Roof Curb Installation Instructions for additional information as required. When accessory roof curb is used, unit may be installed on class A,
B, or C roof covering material.
ALTERNATE UNIT SUPPORT — When the curb or adapter
cannot be used, support unit with sleepers using unit curb or
adapter support area. If sleepers cannot be used, support long
sides of unit (refer to Fig. 3-6) with a minimum number of
equally spaced 4-in. x 4-in. pads as follows:
50EJ,EK,EW,EY024-034 units require 3 pads on each side;
50EJ,EK,EW,EY038-048 require 4 pads on each side. Unit
may sag if supported by corners only.

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. 535-006
Printed in U.S.A.
Form 50E-3SI
Pg 1
8-96
Replaces: 50E-1SI
Tab 1b

NOTE: To prevent standing water in the drain pan of the indoor section
and the heat exchangers, UNIT CAN ONLY BE PITCHED AS SHOWN.
UNIT LEVELING TOLERANCES DIMENSIONS*
(Degrees and Inches)

NOTES:
1. Unless otherwise specified, all dimensions are to outside of part.
2. Roof curb accessory is shipped disassembled.
3. All roof curb parts are to be 16 ga galvanized steel.
4. Dimensions are in inches.

A
Deg.
1.0

B
in.
2.9

Deg.
.50

*From edge of unit to horizontal.

Fig. 1 — Roof Curb (Sizes 024-034)
2

in.
.75

NOTES:
1. Unless otherwise specified, all dimensions are to outside of part.
2. Roof curb accessory is shipped disassembled.
3. All roof curb parts are to be 16 ga galvanized steel.
4. Dimensions are in inches.

NOTE: To prevent standing water in the drain pan of the indoor section and the
heat exchangers, UNIT CAN ONLY BE PITCHED AS SHOWN.
UNIT LEVELING TOLERANCES DIMENSIONS*
(Degrees and Inches)
A
Deg.
1.0

B
in.
2.9

Deg.
.50

*From edge of unit to horizontal.

Fig. 2 — Roof Curb (Sizes 038-048)
3

in.
.75

NOTES:
1. Weights include economizer (Std)
2.

Center of gravity.

3. Do not locate adjacent units with discharge facing economizer inlet. Minimum clearances to be:
Adjacent Units: 158-09
Top of Units: No overhang
Condenser Coil: 48-09
Economizer Side: 68-09
Filter Access Side: 108-09 (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. Dimensions in [ ] are in millimeters.
7. For units with electric heat, a fieldsupplied 90° elbow must be installed
in the supply ductwork below the unit
discharge.
LEGEND
VFD — Variable Frequency Drive

UNIT SIZE
50EJ/EK

OPERATING
WEIGHT
(lb)

024
028
030
034

4016
4102
4102
4102

A

B

ft-in.
5-113⁄8
5- 81⁄2
5- 81⁄2
5- 81⁄2

ft-in.
3-511⁄16
3-75⁄8
3-75⁄8
3-75⁄8

CORNER WEIGHT
(lb)
1
2
3
4
823 914 1199 1080
844 859 1210 1189
844 859 1210 1189
844 859 1210 1189

Fig. 3 — Base Unit Dimensions, 50EJ/EK024-034
4

NOTES:
1. Weights include economizer (Std)
2.

LEGEND
VFD — Variable Frequency Drive

Center of gravity.

3. Do not locate adjacent units with discharge facing economizer inlet. Minimum clearances to be:
Adjacent Units: 158-09
Top of Units: No overhang
Condenser Coil: 48-09
Economizer Side: 68-09
Filter Access Side: 108-09 (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. Dimensions in [ ] are in millimeters.
7. For units with electric heat, a field-supplied 90° elbow must be installed
in the supply ductwork below the unit discharge.

UNIT SIZE OPERATING
WEIGHT
50E
(lb)
J038
J/K044
J048

4282
4508
4795

A

B

ft-in.
ft-in.
7-75⁄16 3-101⁄2
7-313⁄16 3-111⁄2
7-23⁄16 3-103⁄32

CORNER WEIGHT
(lb)
1
2
3
4
961 858 1162 1302
973 868 1258 1409
1007 915 1368 1505

Fig. 4 — Base Unit Dimensions, 50EJ038-048 and 50EK044

5

NOTES:
1. Weights include economizer (Std)
2.

LEGEND
VFD — Variable Frequency Drive

Center of gravity.

3. Do not locate adjacent units with discharge facing economizer inlet. Minimum clearances to be:
Adjacent Units: 158-09
Top of Units: No overhang
Condenser Coil: 48-09
Economizer Side: 68-09
Filter Access Side: 108-09 (for removal of evaporator
coil)
4. For smaller service and operational clearances, contact Carrier Application Engineering department.
5. Dimensions are in inches. Dimensions in [ ] are in
millimeters.
6. For units equipped with electric heat, a field-supplied
90° elbow must be installed in the supply ductwork below the unit discharge.
7. For side-supply/return applications, a single return and
supply ductwork connection is recommended for covering both return and both supply openings.

UNIT SIZE
50EW/EY

OPERATING
WEIGHT
(lb)

024
028
030
034

4016
4102
4102
4102

A

B

ft-in.
5-113⁄8
5- 81⁄2
5- 81⁄2
5- 81⁄2

ft-in.
3-511⁄16
3-75⁄8
3-75⁄8
3-75⁄8

Fig. 5 — Base Unit Dimensions, 50EW/EY024-034

6

CORNER WEIGHT
(lb)
1
2
3
4
823 914 1199 1080
844 859 1210 1189
844 859 1210 1189
844 859 1210 1189

NOTES:
1. Weights include economizer (Std)
2.

LEGEND
VFD — Variable Frequency Drive

Center of gravity.

3. Do not locate adjacent units with discharge facing economizer inlet.
Minimum clearances to be:
Adjacent Units: 158-09
Top of Units: No overhang
Condenser Coil: 48-09
Economizer Side: 68-09
Filter Access Side: 108-09 (for removal of evaporator coil)
4. For smaller service and operational clearances, contact Carrier
Application Engineering department.
5. Dimensions are in inches. Dimensions in [ ] are in millimeters.
6. For units equipped with electric heat, a field-supplied 90° elbow must
be installed in the supply ductwork below the unit discharge.
7. For side-supply/return applications, a single return and supply ductwork connection is recommended for covering both return and both
supply air openings.

UNIT SIZE
50E

OPERATING
WEIGHT
(lb)

W038
W/Y044
W048

4282
4508
4795

A

ft-in.
ft-in.
7-75⁄16 3-101⁄2
7-313⁄16 3-111⁄2
7-23⁄16 3-103⁄32

Fig. 6 — Base Unit Dimensions, 50EW038-048 and 50EY044

7

B

CORNER WEIGHT
(lb)
1
2
3
4
961 858 1162 1302
973 868 1258 1409
1007 915 1368 1505

Four lifting lugs are provided on the unit base rails as shown
in Fig. 7. Refer to rigging instructions on unit.
POSITIONING — Provide clearance around and above unit
for airflow, safety, and service access (Fig. 3-6).
Do not install unit in an indoor location. Do not locate air
inlets near exhaust vents or other sources of contaminated
air.
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.

Step 2 — Rig and Place Unit — Inspect unit for transportation damage. File any claim with transportation agency.
Keep unit upright, and do not drop. Use spreader bars over
unit to prevent sling or cable damage. Rollers may be used
to move unit across a roof. Level by using unit frame as a
reference; leveling tolerance is shown in Fig. 1 and 2. See
Fig. 7 for additional information. Unit weight is shown in
Table 1.
NOTE: On retrofit jobs, ductwork may be attached to old
unit instead of roof curb. Be careful not to damage ductwork
when removing unit. Attach existing ductwork to roof curb
instead of unit.

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 distance of 74 in. (1880 mm) from top of unit to
eyehook.
NOTE:
Add 32 lb
Add 312 lb
Add 346 lb
Add 250 lb
Add 220 lb
Add 285 lb
Add 380 lb

MODEL
50EJ/EK/EW/EY
024
028
030
034
038*
044
048*

A

(14.5 kg) for domestic crating.
(142 kg) for export crating (024-034 units).
(157 kg) for export crating (038-048 units).
(113 kg) for power exhaust.
(100 kg) for copper condenser coil (024-034 units).
(129 kg) for copper condenser coil (038-044 units).
(172 kg) for copper condenser coil (048 unit).

WEIGHT
lb
kg
4016 1822

in.
87.68

mm
2227

in.
71.4

B
mm
1814

in.
41.7

mm
1059

4102

1860

87.68

2227

68.5

1740

43.6

1107

4282
4508
4795

1942
2045
2175

150

3810

91.3
87.8
86.2

2319
2230
2189

46.5
46.5
46.1

1181
1181
1171

*Sizes 038 and 048 are 50EJ,EW units only.

Fig. 7 — Rigging Label

8

C

Table 1 — Physical Data
UNIT 50EJ,EK,EW,EY
NOMINAL CAPACITY (tons)
OPERATING WEIGHT (lb)*
Unit
Al/Al†
Al/Cu†
Roof Curb (14-in. curb)
COMPRESSOR
Type
Ckt 1
Ckt 2
Number of Refrigerant Circuits
Oil (oz) (Ckt1, Ckt 2)
REFRIGERANT TYPE
Operating Charge (lb-oz)
Circuit 1**
Circuit 2
CONDENSER COIL
Quantity
Rows...Fins/in.
Total Face Area (sq ft)
CONDENSER FAN
Nominal Cfm
Quantity...Diameter (in.)
Motor Hp (1075 Rpm)
EVAPORATOR COIL
Rows...Fins/in.
Total Face Area (sq ft)
EVAPORATOR FAN
Quantity...Size (in.)
Type Drive
Nominal Cfm
Motor Hp
Motor Frame Size
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
Belt, Length (in.)
Pulley Center Line Distance (in.)
Factory Speed Setting (rpm)
HIGH-PRESSURE SWITCH (psig)
Cutout
Reset (Auto.)
LOW-PRESSURE SWITCH (psig)
Cutout
Reset (Auto.)
RETURN-AIR FILTERS
Quantity...Size (in.)
OUTDOOR-AIR FILTERS
Quantity...Size (in.)
POWER EXHAUST
Motor, Quantity...Hp
Fan, Diameter...Width (in.)

024
20

028
25

030
27

034
30

4016
4236
365

4102
4322
365

4102
4322
365

4102
4322
365

06D328
06D818
2
115, 88

06D328
06D328
2
115 ea.

06D537
06D328
2
115 ea.

06D537
06D537
2
115 ea.

R-22
25-0
31-0

5
S184T
4.6
11⁄8
11.1
1...BX59
62
16.0-18.7
725

25-0
25-0
25-0
25-0
3
Cross-Hatched ⁄89 Copper Tubes, Aluminum Lanced or Copper Fins
1
1
1
4...15
4...15
4...15
33.3
33.3
33.3
Propeller Type
13,420
13,420
13,420
2...30
2...30
2...30
1
1
1
Cross-Hatched 3⁄89 Copper Tubes, Aluminum or Copper Plate Fins, Intertwined Circuits
4...15
4...15
4...15
31.7
31.7
31.7
Centrifugal Type
2...20x15
2...20x15
2...20x15
Belt
Belt
Belt
8,000
10,000
11,000
10††
15
7.5
10††
15
10
15††
20
10
S215T
S254T
S213T
S215T
S254T
S215T
S254T
S256T
S215T
Ball
Ball
Ball
1200
1200
1200
6.6
6.9
4.9
6.1
7.1
6.6
6.7
7.5
6.4
13⁄8
15⁄8
13⁄8
13⁄8
15⁄8
13⁄8
15⁄8
15⁄8
13⁄8
12.5
11.1
11.1
11.1
11.1
13.7
11.1
11.1
12.5
111⁄16
111⁄16
111⁄16
1...BX60 1...5VX590 1...BX56 1...BX56 1...5VX590 1...BX62 1...5VX590 1...5VX600 1...BX60
63
59
59
59
59
65
59
60
63
15.6-18.4 15.0-17.9 15.6-18.4 15.6-18.4 15.0-17.9 15.6-18.4
15.0-17.9
15.6-18.4
924
1088
773
962
1119
843
1056
1182
896

1
4...15
33.3
13,420
2...30
1
4...15
31.7
2..20x15
Belt
12,000
15††
20
S254T
S256T
Ball
1200
6.9
7.5
15⁄8
15⁄8
11.1
11.1
111⁄16
1...5VX590 1...5VX600
59
60
15.0-17.9
1088
1182

426
320

426
320

426
320

426
320

7
22

7
22

7
22

7
22

10...20x24x2
10...20x24x2
10...20x24x2
10...20x24x2
8...16x25
8...16x25
8...16x25
8...16x25
4...20x25
4...20x25
4...20x25
4...20x25
Direct Drive, 3-Speed, Single-Phase Motor (Factory-Wired For High Speed) and Forward Curved Fan
4...1
11...10
NOTES:
1. See Table 2 for evaporator fan motor data.
2. Sizes 038 and 048 are 50EJ,EW units only.

LEGEND
Al —
Cu —

25-0
25-0

Aluminum
Copper

*Weight of unit does not include variable frequency drive (VFD), barometric relief, or power
exhaust. If a VAV unit (a VFD is installed), add the VFD weight in the table at right.
†Evaporator coil fin material/condenser coil fin material.
**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. For more
drive information, see Table 2.

VFD
(Hp)

9

VFD WEIGHTS (lb)
460 v
22
37
61

5
7.5
10

208/230 v
20
51
51

575 v
60
64
64

15
20

61
63

63
111

109
109

25
30

105
172

112
118

174
180

Table 1 — Physical Data (cont)
UNIT 50EJ,EK,EW,EY
NOMINAL CAPACITY (tons)
OPERATING WEIGHT (lb)*
Unit
Al/Al†
Al/Cu†
Roof Curb (14-in. curb)
COMPRESSOR
Type
Ckt 1
Ckt 2
Number of Refrigerant Circuits
Oil (oz) (Ckt1, Ckt 2)
REFRIGERANT TYPE
Operating Charge (lb-oz)
Circuit 1**
Circuit 2
CONDENSER COIL
Quantity
Rows...Fins/in.
Total Face Area (sq ft)
CONDENSER FAN
Nominal Cfm
Quantity...Diameter (in.)
Motor Hp (1075 Rpm)
EVAPORATOR COIL
Rows...Fins/in.
Total Face Area (sq ft)
EVAPORATOR FAN
Quantity...Size (in.)
Type Drive
Nominal Cfm
Motor Hp
Motor Frame Size
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
Belt, Length (in.)
Pulley Center Line Distance (in.)
Factory Speed Setting (rpm)
HIGH-PRESSURE SWITCH (psig)
Cutout
Reset (Auto.)
LOW-PRESSURE SWITCH (psig)
Cutout
Reset (Auto.)
RETURN-AIR FILTERS
Quantity...Size (in.)
OUTDOOR-AIR FILTERS
Quantity...Size (in.)
POWER EXHAUST
Motor, Quantity...Hp
Fan, Diameter...Width (in.)

038
35

044
40

048
45

4282
4567
410

4508
4793
410

4795
5175
410

06D537
06D537
2
115 ea.

06EA250
06EA250
2
224 ea.
R-22

06EA265
06EA250
2
304, 224

34-0
34-0

35-0
41-0
35-0
41-0
Cross-Hatched ⁄ 9 Copper Tubes, Aluminum Lanced or Copper Fins
2
2
1
1
3...15
3...15
4...15
3...15
58.3
58.3
66.7
Propeller Type
27,064
27,064
27,064
4...30
4...30
4...30
1
1
1
Cross-Hatched 3⁄89 Copper Tubes, Aluminum or Copper Plate Fins, Intertwined Circuits
3...15
3...15
4...15
34.7
34.7
34.7
Centrifugal Type
2..20x15
2...20x15
2...20x15
Belt
Belt
Belt
14,000
16,000
18,000
15††
20
15
20††
25
20
25††
30
S254T
S256T
S254T
S256T
S284T
S256T
S284T
S286T
Ball
Ball
Ball
1200
1200
1200
6.9
7.5
6.9
8.1
9.1
5.3
5.9
7.5
15⁄8
15⁄8
15⁄8
15⁄8
11⁄8
15⁄8
17⁄8
17⁄8
12.5
12.5
12.5
13.7
13.7
9.1
9.1
11.1
111⁄16
111⁄16
111⁄16
1...5VX630
1...5VX650
1...5VX630
1...5VX670
2...5VX680
1...5VX550
2...5VX560
2...5VX610
63
65
63
67
68
55
56
59
15.0-17.9
15.0-17.9
14.6-17.6
15.0-17.9
14.6-17.6
14.6-17.6
966
1050
1066
1035
1162
1019
1135
1182
38

10
S215T
4.1
13⁄8
9.1
1...BX51
54
15.6-18.4
788

426
320

426
320

426
320

7
22

7
22

7
22

10...20x24x2
10...20x24x2
10..20x24x2
8...16x25
8...16x25
8...16x25
4...20x25
4...20x25
4...20x25
Direct Drive, 3-Speed, Single-Phase Motor (Factory-Wired For High Speed) and Forward Curved Fan
4...1
11...10
NOTES:
1. See Table 2 for optional evaporator fan motor data.
2. Sizes 038 and 048 are 50EJ,EW units only.

LEGEND
Al — Aluminum
Cu — Copper
*Weight of unit does not include variable frequency drive (VFD), barometric relief, or power
exhaust. If a VAV unit (a VFD is installed), add the VFD weight in the table at right.
†Evaporator coil fin material/condenser coil fin material.
**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. For more
drive information, see Table 2.

VFD
(Hp)

10

VFD WEIGHTS (lb)
460 v
22
37
61

5
7.5
10

208/230 v
20
51
51

575 v
60
64
64

15
20

61
63

63
111

109
109

25
30

105
172

112
118

174
180

Table 2 — Evaporator Fan Motor Data
UNIT
SIZE

024

028

030

034

038

044

048

MOTOR
HP

MOTOR
SHAFT
DIAMETER
(in.)

FAN
SHAFT
SPEED
(rpm)

MOTOR
SHEAVE

5
10
15
7.5
10
15
10
15
20
10
15
20
10
15
20
15
20
25
20
25
30

1.12
1.38
1.62
1.38
1.38
1.62
1.38
1.62
1.62
1.38
1.62
1.62
1.38
1.62
1.62
1.62
1.62
1.88
1.62
1.88
1.88

725
924
1088
773
962
1119
843
1056
1182
896
1088
1182
788
966
1050
966
1035
1162
1019
1135
1182

BK52
BK72
1B5V68
BK55H
BK67H
1B5V70
BK72
1B5V66
1B5V74
BK70H
1B5V68
1B5V74
2BK47
1B5V68
1B5V74
1B5V68
1B5V80
1B5V90
2B5V52
2B5V58
2B5V76

MOTOR
SHEAVE
PITCH
DIAMETER
(in.)
4.6
6.6
6.9
4.9
6.1
7.1
6.6
6.7
7.5
6.4
6.9
7.5
4.1
6.9
7.5
6.9
8.1
9.1
5.3
5.9
7.5

BUSHING
DIAMETER
(in.)

FAN
SHEAVE

None-1.125
None-1.375
B-1.625
H-1.375
H-1.375
B-1.625
None-1.375
B-1.625
B-1.625
H-1.375
B-1.625
B-1.625
None-1.375
B-1.625
B-1.625
B-1.625
B-1.625
B-1.875
B-1.625
B-1.875
B-1.875

1B5V110
1B5V124
1B5V110
1B5V110
1B5V110
1B5V110
1B5V136
1B5V110
1B5V110
1B5V124
1B5V110
1B5V110
2B5V90
1B5V124
1B5V124
1B5V124
1B5V136
1B5V136
2B5V90
2B5V90
2B5V110

FAN
SHEAVE
PITCH
DIAMETER
(in.)
11.1
12.5
11.1
11.1
11.1
11.1
13.7
11.1
11.1
12.5
11.1
11.1
9.1
12.5
12.5
12.5
13.7
13.7
9.1
9.1
11.1

BUSHING
DIAMETER
(in.)

BELT

OUTSIDE
BELT
LENGTH

BELT
TENSION
(Lb @
.24 in.)

B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875
B-1.6875

BX59
BX60
5VX590
BX56
BX56
5VX590
BX62
5VX590
5VX600
BX60
5VX590
5VX600
BX51
5VX630
5VX650
5VX630
5VX670
5VX680
5VX550
5VX560
5VX610

62
63
59
59
59
59
65
59
60
63
59
60
54
63
65
63
67
68
55
56
59

5.02
7.05
9.38
6.87
7.26
9.17
6.96
9.60
11.67
7.20
9.38
11.17
5.49
9.22
10.02
9.54
10.37
10.88
7.93
8.66
9.07

NOTE: Motor shaft speed is 1750 rpm. The fan shaft diameter is 111⁄16 inches.

ROOF MOUNT — Check building codes for weight distribution requirements.

Step 3 — Field Fabricate Ductwork — Secure all
ducts to building structure. Use flexible duct connectors between unit and ducts as required. Insulate and weatherproof
all external ductwork, joints, and roof openings with counter
flashing and mastic in accordance with applicable codes.
Ducts passing through an unconditioned space must be
insulated and covered with a vapor barrier.
To attach ductwork to roof curb, insert ductwork approximately 10 to 11 in. up into the curb. Connect ductwork to
14-gage roof curb material using sheet metal screw driven
from inside the duct.
The units with electric heat require a 1-in. clearance for
the first 24 in. of ductwork.
NOTE: A 90-degree elbow must be provided in the ductwork to comply with UL (Underwriters’ Laboratories) codes
for use with electric heat.
Outlet grilles must not lie directly below unit discharge.

Fig. 8 — Air Distribution — Thru-the-Bottom

Step 4 — Make Unit Duct Connections
50EJ,EK UNITS — Unit is shipped for through-the-bottom
duct connections. Ductwork openings are shown in Fig. 3
and 4. Attach all ductwork to roof curb. Air distribution
is shown in Fig. 8. Refer to installation instructions shipped
with accessory roof curb for more information.
50EW,EY UNITS — Remove shipping covers from supply
and return air openings. Attach field-supplied ductwork to
unit. Use a single duct over both return openings and a single
duct over both supply openings. See Fig. 5 and 6 for duct
opening dimensions. Secure all ducts to the building structure. See Fig. 9. Use flexible duct connectors between unit
and ducts as required.
Install accessory barometric relief or power exhaust in the
field-fabricated return ductwork. Refer to Position Power
Exhaust/Barometric Relief Damper Hood Section on
page 29 for more information.

Fig. 9 — Air Distribution — Thru-the-Side
the drain location. One 1-in. FPT coupling is provided inside unit evaporator section for condensate drain connection. A trap at least 4-in. deep must be used. 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 quality guidelines.

Step 5 — Trap Condensate Drain — See Fig. 3-6
and 10 for drain location. Condensate drain is open to the
atmosphere and must be trapped. Install a trapped drain at

11

• 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
• provide power exhaust output to an external power exhaust controller
• support a field test for field checkout
• control of 2 stages of CV power exhaust
• compressor Time Guardt (power up and minimum off and
on times)
Additional features are provided by accessing the standard unit control board via software with a computer. These
features are:
• electronic expansion board features (if installed)
• compressor lockout during low supply air temperature
• control board diagnostics
• ability to change supply air set point (economizer control)
• ability to change high outdoor air temperature lockout set
point (economizer control)
• ability to change power exhaust set points
NOTE: A CV unit without a thermostat requires a fieldsupplied sensor for operation.

Fig. 10 — Condensate Drain Connections
(Typical Roof Curb or Slab Mount Shown)

Step 6 — Controls Options — The control options
that the units can provide are based on the following parameters: CV (constant volume) or VAV (variable air volume)
operation; stand-alone unit with field-supplied sensors installed (CV or VAV); as a system via the Carrier Comfort
System (TEMP or VVT); optional electronic expansion board
installed (CV or VAV); linked to the Carrier Comfort Network; and availability of a computer and software (Comfort
Works, Building Supervisor, and Service Tool) to access the
base control board. See Table 3.
NOTE: Access to the base control board allows unit occupancy schedules, unit timeclock, and various set points to be
changed from their factory-defined default settings.

Features with Sensor Control of Unit (Stand-Alone Applications — Unit control is limited to CV unoccupied default
set points, 90 F for cooling, 55 F for heating. There are
3 sensor options available:
• T-57 sensor will monitor room temperature
• T-55 sensor will monitor room temperature and provide
unoccupied override capability (1 hour)
• T-56 sensor will monitor room temperature, provide unoccupied override capability (1 hour), and provide a temperature offset of 5° F.
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 occupied or unoccupied set point
• enable heating (if installed) or cooling during unoccupied
periods as required to maintain space temperature within
the unoccupied set points
• adjustment of space temperature set points of ± 5° F when
using a T-56 sensor

CONSTANT VOLUME APPLICATIONS — The standard
CV unit is capable of being operated with either a Carrierapproved thermostat or a field-supplied sensor. (See Price
Pages for ordering information.)
Features with Thermostat Control of Unit
• two-stage heating (if installed)
• 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

Table 3 — Controls Options and Configurations (Non-Thermostat Applications)
UNIT CONFIGURATION
DEFAULT COOLING
UNITS RUNNING VERSION 1.0 UNIT CONTROL SOFTWARE
Unoccupied Cooling — 90 F (SPT)
CV or VAV Unit with SPT Sensor
Occupied Cooling — NA
CV Unit with SPT Sensor and Remote
Unoccupied Cooling — 90 F (SPT)
Start/Stop Switch
Occupied Cooling — 78 F (SPT)
Unoccupied Cooling — NA
VAV Unit Remote Start/Switch Only
Occupied Cooling — 55 F (SAT)
VAV Unit with SPT Sensor and Remote
Unoccupied Cooling — 90 F (SPT)
Start/Stop Switch
Occupied Cooling — 55 F (SAT)
UNITS RUNNING VERSION 2.0 UNIT CONTROL SOFTWARE
Unoccupied Cooling — 90 F (SPT)
CV or VAV Unit with SPT Sensor
Occupied Cooling — NA
CV Unit with SPT Sensor and Remote
Unoccupied Cooling — 90 F (SPT)
Start/Stop Switch
Occupied Cooling — 78 F (SPT)
Unoccupied Cooling — 90 F (RAT)
VAV Unit Remote Start/Stop Switch Only
Occupied Cooling — 55 F (SAT)
VAV Unit with SPT Sensor and Remote
Unoccupied Cooling — 90 F (SPT)
Start/Stop Switch
Occupied Cooling — 55 F (SAT)
LEGEND
CV — Constant Volume
SAT — Supply-Air Temperature
NA — Not Available
SPT — Space Temperature
RAT — Return-Air Temperature
VAV — Variable Air Volume

DEFAULT HEATING
Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating

— 55 F (SPT)
— NA
— 55 F (SPT)
— 68 F (SPT)
— NA
— NA
— 55 F (SPT)
— NA

Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating
Unoccupied Heating
Occupied Heating

— 55 F (SPT)
— NA
— 55 F (SPT)
— 68 F (SPT)
— 55 F (RAT)
— 68 F (RAT)*
— 55 F (SPT)
— 68 F (RAT)*

*With DIP Switch No. 5 configured to OPEN (Occupied Heat Enabled).
NOTE: Space temperature sensor and remote stop/switch are field-supplied.

12

or during unexpected power outages. For complete Carrier
Comfort System (CCS) or Carrier Comfort Network (CCN)
features and benefits, refer to the product literature.
VARIABLE AIR VOLUME (VAV) APPLICATIONS
Features with Stand-Alone Applications — A VAV unit is
capable of providing unoccupied cooling controlling to a
90 F return-air temperature utilizing the factory-supplied returnair thermistor located below the return-air damper in the returnair section for unit control. The unit will provide unoccupied
heating (if electric heat is installed) controlling to a 55 F
return-air temperature. Also provided is a morning warm-up
which is initiated by the Occupied mode (if electric heat is
installed) and continues until the return-air temperature rises
to 68 F. The unit will provide occupied cooling with a default temperature of 55 F for the supply air. The supply-air
temperature is measured by the supply-air thermistor, located in the indoor fan compartment.
Standard features of a VAV unit with a remote start/stop
switch are:
• 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 temperature as a set point
• support of remote occupied/unoccupied input to start or
stop the unit
• provide power exhaust output to an external power exhaust 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 6 stages plus economizer with
compressors and unloaders to maintain supply air temperature set point during occupied periods
• control of one stage of heat to maintain supply air temperature at supply air set point during occupied periods
• provide a variable frequency drive high voltage relay output to enable VFD
• control of heat interlock relay
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.

Features with sensor control of unit with computer access
are:
• 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
• ability to initiate timed override from T-55 or T-56 sensors
• ability to use multiple space temperature sensors to average the space temperature
• supply air temperature reset for the supply air temperature
set point
• temperature compensated start to calculate early start times
before occupancy
• access to the Display, Maintenance, Configuration, Service, and Set Point data table 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 (if electric heat is installed). See Fig. 11 for remote start/stop wiring.
NOTE: For units 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 returnair 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 (if electric heat
is installed).
An electronic expansion board may be field-installed to
provide the following features:
• control of modulating economizer damper to maintain
indoor air quality (IAQ) when outdoor conditions are
suitable
• provide discrete inputs for fan status, filter status, fieldapplied status, and demand limit
• provide an output for the external alarm light indicator
When the unit is connected to the CCN (Carrier Comfort
Network), the following expansion board features can be
utilized.
• 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 power exhaust fire outputs for direct control of
modulated power exhaust stages during fire or smoke modes
• smoke control modes including evacuation, smoke purge,
pressurization, and fire shutdown (modulating power exhaust required)
• provides CCN IAQ participation
See Carrier TEMP or VVTt (Variable Volume and Temperature) literature for complete TEMP (single zone) or VVT
(multi-zone) application information.
Features with Sensor Control of Unit (Network Applications) — The base control board provides, as standard, a connection 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 Comfort Works, Building Supervisor, or Service Tool, the following features can be accessed:
• 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 communication bus. See Fig. 12. The timeclock has a 10-hour minimum
back-up time to provide for unit power off for servicing unit

NOTE: On units running Version 1.0 of the Unit Control Software, the remote
start/stop switch is connected to R and Y1. On units running Version 2.0 of the
Unit Control Software, the remote start/stop switch is connected to R and W1.

Fig. 11 — Field Control Remote Start/Stop
13

14
Fig. 12 — Control Board Diagram

CCN —
COM —
D
—
N.C. —
N.O. —
*Where X

LEGEND
Carrier Comfort Network
R
—
Common
SIO —
Diode
SW —
Normally Closed
T
—
Normally Open
is the unit control software version (1 or 2).

Relay
Serial Input/Output
Switch
Terminal

an occupancy schedule, the unit will control to the unoccupied default set points of 90 F (return air) cooling and 55 F
(return air) heating (if electric heat is installed).
Features with Network Applications — 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 Comfort Works, Building Supervisor, or Service Tool
software, the following features can be accessed:
• 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 communication bus. See Fig. 12. The timeclock has a 10-hour minimum back-up time to provide for unit power off for servicing 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.

For units running Version 1.0 of the unit control software,
network access software is required to enable occupied heating. For units running Version 2.0 of the unit control software, occupied heating is enabled or disabled by the position of DIP switch no. 5.
Additional features may be provided with electronic access to Unit Control Board. These features are:
• control board diagnostics
• compressor time guard override (power up, minimum off
and on times)
• compressor lockout during low supply-air temperature
• electronic expansion board features (if installed)
• field test capability
• control of the economizer damper and indoor fan to option unoccupied free cooling
• 365 day timeclock with backup (supports minute, hour, day,
month, and year)
• holiday table containing up to 18 holiday schedules
• occupancy control with 8 periods for unit operation
• support a set of display, maintenance, configuration, service, and set point data tables for interface with Building
Supervisor, Comfort Works, or Service Tool
When a VAV unit with a space temperature sensor is accessed via a computer, the following additional features are
available:
• ability to initiate timed override from T-55 sensors
• ability to use multiple space temperature sensors to average space temperature
• 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 occupied cooling set point
An electronic expansion board may be field-installed to
provide the following features:
• fan status
• filter status
• field-applied status
• demand limiting
• IAQ sensor
• OAQ sensor
• alarm light
When the unit is connected to the CCN (Carrier Comfort
Network), the following expansion board features can be
utilized:
• CCN IAQ (indoor air quality) participation
• CCN OAQ (outdoor air quality) participation
• CCN demand limit participation
• fire unit shutdown
• fire pressurization
• fire evacuation
• fire smoke purge
• modulated power exhaust override
A field-supplied space temperature sensor can be added to
provide the following:
• T-57 sensor will monitor room temperature
• T-55 sensor will monitor room temperature and provide
unoccupied override capability (1 hour)
When the unit is equipped with a field-supplied space temperature sensor and a remote contact closure (remote start/
stop), the occupied default set points will monitor unit operation. The occupied default set points are 55 F (supply air)
cooling and 68 F (space temperature) heating (if electric heat
is installed). See Fig. 11 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 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 of 55 F (supply-air temperature)
cooling and 68 F (return-air temperature) heating. Without

Step 7 — Make Electrical Connections
POWER WIRING — Units are factory wired for the voltage
shown on the unit nameplate. The main terminal block is
suitable for use with aluminum or copper wires and is sized
for single-point electric heat.
When installing units, provide a disconnect per NEC (National Electrical Code) of adequate size (MOCP [maximum
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. 13 for power wiring connections 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. 13. Units have circuit
breakers for compressors, fan motors, and control circuit. If
required by local codes, provide an additional disconnect,
per NEC and local codes requirements, of adequate size
(Table 4). 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 (American
National Standards Institute) C1-latest year.
All field wiring must comply with NEC and local code
requirements.
FIELD POWER SUPPLY — Unit is factory wired for voltage shown on 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 (corner post next to control box).

LEGEND
EQUIP — Equipment
GND
— Ground
NEC
— National Electrical Code
TB
— Terminal Block
NOTE: Maximum wire size for TB1 is 500 MCM.

Fig. 13 — Field Power Wiring Connections
15

A 31⁄2-in. NPT coupling for field power wiring and a
⁄ -in. NPT coupling for 24-v control wiring are provided in
basepan. In the side post, there are two 21⁄2-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
side of unit, a 7⁄8-in. diameter hole is provided in the condenser side post next to the control box.
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
31⁄2-in. hole to the disconnect box and back into unit to the
main control box.
Use strain relief going into control box through 21⁄2-in.
diameter hole provided. After wires are in unit control box,
connect to power terminal block (see Power Wiring section
on this page 15).
Low-voltage wiring must be run in watertight conduit from
the basepan to control box and through 7⁄8-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 terminal blocks (see Field Control Wiring section on this page).
Install conduit connector in unit basepan or side panel openings provided. Route power and ground lines through connector to connections in unit control box as shown on unit
wiring diagram and Fig. 13.
Routing Through Side of Unit — Route power wiring in
field-supplied watertight conduit into unit through 21⁄2- or
3-in. hole. Strain relief (field supplied) must be used in hole.
See Fig. 13.
Use field-supplied strain relief going into control box through
21⁄2- or 3-in. diameter hole provided. After wires are in unit
control box, connect to power terminal block (see Power Wiring section on page 15).
Bring low-voltage control wiring through factory-drilled
7⁄8-in. diameter hole in condenser side post. Use strain relief
going into 7⁄8-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 section on this page).

IMPORTANT: If the supply voltage phase imbalance
is more than 2%, contact your local electric utility company immediately.

34

Unit failure as a result of operation on improper line voltage or excessive phase imbalance constitutes abuse and may
cause damage to 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. Disconnect orange wire from black unit power wire.
3. Cap orange wire.
4. Splice red wire and black unit power wire. Cap wires.
IMPORTANT: Be certain unused wires are capped.
Failure to do so may damage the transformers.
FIELD CONTROL WIRING — Install either a Carrierapproved accessory 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. 14 and 15.
Thermostat Wiring (CV Only) — Install a Carrier-approved
accessory thermostat assembly (per current price pages) according to the installation instructions included with the accessory or these instructions. Locate thermostat assembly on
a solid wall in the conditioned space to sense average
temperature.
Route thermostat cable or equivalent single leads of colored wire from subbase terminals to low-voltage connections as shown on unit label wiring diagram and in Fig. 16.
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 minimum).
All wire larger than no. 18 AWG cannot be directly connected to the thermostat and will require a junction box and
splice at the thermostat.
Set heat anticipators settings to 0.1 for all voltages. Settings may be changed slightly to provide a greater degree of
comfort for a particular installation.
Sensor Wiring (CV or VAV) — The temperature sensor is
wired into the unit control board. See Fig. 17.
The unit is controlled with a T55, T56 (CV only), or T57
zone sensor. Terminal TH on the sensor is connected to T1
of the base module board. Terminal COM on the sensor is
connected to T2 on the base module board. If a T56 set point
override sensor is used, the override connection SW on the
sensor is connected to T3 on the base module board.
VAV units using Version 1.0 of the unit control software
may operate without a space temperature sensor during occupied schedules, but unit will not provide unoccupied heating or cooling.
VAV Units — VAV units require a field-supplied heat interlock relay (HIR) to drive the air terminal wide open when in
heat mode. The HIR part number is HN61KK041.
Remote Field Control (Units Running Version 1.0 of Unit
Control Software) — A switch closure across terminals R
and Y1 on TB-3 will initiate the Occupied mode. This can
be done manually as well as through a field-supplied
timeclock.

IMPORTANT: THE VAV (variable air volume) units
incorporate VFD (variable frequency drives) which generate, use, and can radiate radio frequency energy. If
units are not installed 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 computing device as defined by FCC (Federal
Communications Commission) regulations, Subpart J
of Part 15, which are designed to provide reasonable
protection against such interference when operated in
a commercial environment.

The unit must be electrically grounded in accordance
with local codes and NEC ANSI/NFPA 70 (National Fire
Protection Association).
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, voltages between phases must be balanced within 2% and the
current must be balanced within 10%.
Use the formula in Table 4 to determine the percentage of
voltage imbalance.
16

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

024

460

575

FLA
HACR
IFM
LRA
MCA
MOCP
NEC
OFM
RLA

—
—
—
—
—
—
—
—
—

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

39.1

19.9

16.0

228

114

91

25.6

11.5

9.6

160

80

64

OFM
Qty

2

2

2

Hp

1

1

1

FLA (ea)

5.3

2.7

2.4

FLA

5

16.7/
15.2

10

30.8/
28.0

15

46.2/
42.0

5

7.6

10

14

15

21

5

6.1

10

11

15

17

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
101.8/100.3
125.4/123.9
114.7/127.3
144.2/156.8
171.0/192.2
200.5/221.7
115.9/113.1
139.5/136.7
132.3/143.3
161.8/172.8
188.6/208.2
218.1/237.7
131.3/127.1
154.9/150.7
151.6/160.8
181.1/190.3
207.9/225.7
237.4/255.2
49.4
62.0
63.6
79.4
96.1
111.9
55.8
68.4
71.6
87.4
104.1
119.9
62.8
75.4
80.4
96.1
112.9
128.6
40.5
53.1
50.9
66.7
76.9
92.7
45.4
58.0
57.1
72.8
83.0
98.8
51.4
64.0
64.6
80.3
90.5
106.3

MOCP†
125/125
150/150
125/150
150/175
200/225
225/225
150/150
175/175
150/150
175/175
220/225
250/250
150/150
175/175
175/175
200/200
250/250
275/275
60
80
70
80
110
125
70
80
80
90
110
125
80
90
90
100
125
150
50
60
60
70
80
100
60
70
60
80
90
100
60
80
70
90
100
110

deviation from average voltage.
5v
7v
2v

Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7

% Voltage Imbalance = 100 x

457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the maximum
allowable 2%.

*Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 575 v.
If power distribution voltage to unit varies from rated heater voltage, heater kW will
vary accordingly.
†Fuse or HACR circuit breaker.

IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.

NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit
breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%. Use the following formula to determine the percent of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
average voltage

3. MCA calculation for units with electric heaters over 50 kW = (1.25 x IFM amps) +
(1.00 x heater FLA).

452 + 464 + 455
3

=

Hp

Determine maximum
(AB) 457 − 452 =
(BC) 464 − 457 =
(AC) 457 − 455 =

LEGEND
Full Load Amps
Heating, Air Conditioning and Refrigeration
Indoor (Evaporator) Fan Motor
Locked Rotor Amps
Minimum Circuit Amps
Maximum Overcurrent Protection
National Electrical Code
Outdoor (Condenser) Fan Motor
Rated Load Amps

EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =

POWER
EXHAUST

IFM

1371
3

= 457

17

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

028

460

575

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

39.1

19.9

16.0

228

114

91

39.1

19.9

16.0

228

114

91

OFM
Qty

2

2

2

Hp

1

1

1

POWER
EXHAUST

IFM

FLA (ea)

5.3

2.7

2.4

18

Hp

FLA

7.5

24.2/
22.0

10

30.8/
28.0

15

46.2/
42.0

7.5

11

10

14

15

21

7.5

9

10

11

15

17

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
122.8/120.6
146.4/144.2
124.1/135.8
153.6/165.3
180.4/200.7
209.9/230.2
129.4/126.6
153.0/150.2
132.3/143.3
161.8/172.8
188.6/208.2
218.1/237.7
144.8/140.6
168.4/164.2
151.6/160.8
181.1/190.3
207.9/225.7
237.4/255.2
61.2
73.8
67.9
83.6
100.4
116.1
64.2
76.8
71.6
87.4
104.1
119.9
71.2
83.8
80.4
96.1
112.9
128.6
49.8
62.4
54.6
70.3
80.5
96.3
51.8
64.4
57.1
72.8
83.0
98.8
57.8
70.4
64.6
80.3
90.5
106.3

MOCP†
150/150
175/175
150/150
175/175
200/225
225/250
150/150
175/175
150/150
175/175
200/225
225/250
175/175
200/200
175/175
200/200
250/250
275/275
80
90
70
90
110
125
80
90
80
90
110
125
90
100
90
100
125
150
60
70
60
80
90
100
60
80
60
80
90
100
70
80
70
90
100
110

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

030

460

575

FLA
HACR
IFM
LRA
MCA
MOCP
NEC
OFM
RLA

—
—
—
—
—
—
—
—
—

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

57.1

25.6

20.5

266

120

96

39.1

19.9

16.0

228

114

91

OFM
Qty

2

2

2

Hp

1

1

1

FLA (ea)

5.3

2.7

2.4

FLA

10

30.8/
28.0

15

46.2/
42.0

20

59.4/
54.0

10

14

15

21

20

27

10

11

15

17

20

22

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
−
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.2/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
151.9/149.1
175.5/172.7
151.9/149.1
175.5/172.8
188.6/208.2
218.1/237.7
167.3/163.1
190.9/186.7
167.3/163.1
190.9/186.7
207.9/225.7
237.4/255.2
180.5/175.1
204.1/198.7
180.5/175.1
204.1/198.7
224.4/240.7
253.9/270.2
71.3
83.9
71.6
87.4
104.1
119.9
78.3
90.9
80.4
96.1
112.9
128.6
84.3
96.9
87.9
103.6
120.4
136.1
57.4
70.0
57.4
72.8
83.0
98.8
63.4
76.0
64.6
80.3
90.5
106.3
68.4
81.0
70.8
86.6
96.8
112.5

MOCP†
200/200
225/225
200/200
225/225
200/225
225/250
200/200
225/225
200/200
225/225
250/250
275/275
225/225
250/250
225/225
250/250
275/275
300/300
90
100
90
100
110
125
100
110
100
110
125
150
100
110
100
110
125
150
70
90
70
90
90
100
80
90
80
90
100
110
80
100
80
100
110
125

deviation from average voltage.
5v
7v
2v

Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7

% Voltage Imbalance = 100 x

457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the maximum
allowable 2%.

*Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 575 v.
If power distribution voltage to unit varies from rated heater voltage, heater kW will
vary accordingly.
†Fuse or HACR circuit breaker.

IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.

NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit
breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%. Use the following formula to determine the percent of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
average voltage

3. MCA calculation for units with electric heaters over 50 kW = (1.25 x IFM amps) +
(1.00 x heater FLA).

452 + 464 + 455
3

=

Hp

Determine maximum
(AB) 457 − 452 =
(BC) 464 − 457 =
(AC) 457 − 455 =

LEGEND
Full Load Amps
Heating, Air Conditioning and Refrigeration
Indoor (Evaporator) Fan Motor
Locked Rotor Amps
Minimum Circuit Amps
Maximum Overcurrent Protection
National Electrical Code
Outdoor (Condenser) Fan Motor
Rated Load Amps

EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =

POWER
EXHAUST

IFM

1371
3

= 457

19

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

034

460

575

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

57.1

25.6

20.5

266

120

96

57.1

25.6

20.5

266

120

96

OFM
Qty

2

2

2

Hp

1

1

1

POWER
EXHAUST

IFM

FLA (ea)

5.3

2.7

2.4

20

Hp

FLA

10

30.8/
28.0

15

46.2/
42.0

20

59.4/
54.0

10

14

15

21

20

27

10

11

15

17

20

22

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
169.9/167.1
193.5/190.7
169.9/167.1
193.5/190.7
188.6/208.2
218.1/237.7
185.3/181.1
208.9/204.7
185.3/181.1
208.9/204.7
207.9/225.7
237.4/255.2
198.5/193.1
222.1/216.7
198.5/193.1
222.1/216.7
224.4/240.7
253.9/270.2
77.0
89.6
77.0
89.6
104.1
119.9
84.0
96.6
84.0
96.6
112.9
128.6
90.0
102.6
90.0
103.6
120.4
136.1
61.9
74.5
61.9
74.5
83.0
98.8
67.9
80.5
67.9
80.5
90.5
106.3
72.9
85.5
72.9
86.6
96.8
112.5

MOCP†
225/200
250/225
225/200
250/225
225/225
250/250
225/225
250/250
225/225
250/250
250/250
275/275
250/250
275/250
250/250
275/250
275/275
300/300
100
110
100
110
110
125
100
110
100
110
125
150
110
125
110
125
125
150
80
90
70
90
90
100
80
100
80
100
100
110
90
100
90
100
110
125

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

038

460

575

FLA
HACR
IFM
LRA
MCA
MOCP
NEC
OFM
RLA

—
—
—
—
—
—
—
—
—

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

57.1

25.6

20.5

266

120

96

57.1

25.6

20.5

266

120

96

OFM
Qty

4

4

4

Hp

1

1

1

FLA (ea)

5.3

2.7

2.4

FLA

10

30.8/
28.0

15

46.2/
42.0

20

59.4/
54.0

10

14

15

21

20

27

10

11

15

17

20

22

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
180.5/177.7
204.1/201.3
180.5/177.7
204.1/201.3
188.6/208.2
218.1/237.7
195.9/191.7
219.5/215.3
195.9/191.7
219.5/215.3
207.9/225.7
237.4/255.2
209.1/203.7
232.7/227.3
209.1/203.7
232.7/227.3
224.4/240.7
253.9/270.2
82.4
95.0
82.4
95.0
104.1
119.9
89.4
102.0
89.4
102.0
112.9
128.6
95.4
108.0
95.4
108.0
120.4
136.1
66.7
79.3
66.7
79.3
83.0
98.8
72.7
85.3
72.7
85.3
90.5
106.3
77.7
90.3
77.7
90.3
96.8
112.5

MOCP†
225/225
250/250
225/225
250/250
225/225
250/250
250/225
275/250
250/225
275/250
250/250
275/275
250/250
275/275
250/250
275/275
275/275
300/300
100
110
100
110
110
125
110
125
110
125
125
150
110
125
110
125
125
150
80
90
80
90
90
100
90
100
80
100
100
110
90
110
90
110
110
125

deviation from average voltage.
5v
7v
2v

Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7

% Voltage Imbalance = 100 x

457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the maximum
allowable 2%.

*Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 575 v.
If power distribution voltage to unit varies from rated heater voltage, heater kW will
vary accordingly.
†Fuse or HACR circuit breaker.

IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.

NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit
breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%. Use the following formula to determine the percent of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
average voltage

3. MCA calculation for units with electric heaters over 50 kW = (1.25 x IFM amps) +
(1.00 x heater FLA).

452 + 464 + 455
3

=

Hp

Determine maximum
(AB) 457 − 452 =
(BC) 464 − 457 =
(AC) 457 − 455 =

LEGEND
Full Load Amps
Heating, Air Conditioning and Refrigeration
Indoor (Evaporator) Fan Motor
Locked Rotor Amps
Minimum Circuit Amps
Maximum Overcurrent Protection
National Electrical Code
Outdoor (Condenser) Fan Motor
Rated Load Amps

EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =

POWER
EXHAUST

IFM

1371
3

= 457

21

Table 4 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

044

460

575

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

69.2

28.8

26.7

345

173

120

69.2

28.8

26.7

345

173

120

OFM
Qty

4

4

4

Hp

1

1

1

IFM

FLA (ea)

5.3

2.7

2.4

22

Hp

FLA

15

46.2/
42.0

20

59.4/
54.0

25

74.8/
68.0

15

21

20

27

25

34

15

17

20

22

25

27

POWER
EXHAUST
FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
−
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.2/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
223.1/218.9
246.7/242.5
223.1/218.9
246.7/242.5
223.1/225.7
246.7/255.2
236.3/230.9
259.9/254.5
236.3/230.9
259.9/254.5
236.3/240.7
259.9/270.2
251.7/244.9
275.3/268.5
251.7/244.9
275.3/268.5
251.7/258.2
275.3/287.7
96.6
109.2
96.6
109.2
112.9
128.6
102.6
115.2
102.6
115.2
120.4
136.1
109.6
122.2
109.6
122.2
129.1
144.9
86.7
99.3
86.7
99.3
91.4
106.3
91.7
104.3
91.7
104.3
96.8
112.5
96.7
109.3
96.7
109.3
103.0
118.8

MOCP†
275/275
300/300
275/275
300/300
275/275
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
125
125
125
125
125
150
125
125
125
125
150
150
125
150
125
150
150
175
110
125
110
125
110
125
110
125
110
125
125
125
110
125
110
125
125
125

Table 3 — Electrical Data — 50EJ,EK,EW,EY024-048 (cont)
UNIT
SIZE

NOMINAL
VOLTAGE
(3 Ph 60 Hz)

208/230

048

460

575

FLA
HACR
IFM
LRA
MCA
MOCP
NEC
OFM
RLA

—
—
—
—
—
—
—
—
—

VOLTAGE
RANGE
Min

187

414

518

Max

254

508

632

COMPRESSOR
No. 1
No. 2
RLA LRA RLA LRA

82.1

42.3

34.6

446

223

164

69.2

28.8

26.7

345

173

120

OFM
Qty

4

4

4

Hp

1

1

1

IFM

FLA (ea)

5.3

2.7

2.4

20

59.4/
54.0

25

74.8/
68.0

30

88.0/
80.0

20

27

25

34

30

40

20

22

25

27

30

32

FLA
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
−
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6
—
12.6

LRA
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
41.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6
—
23.6

ELECTRIC
HEAT*
kW
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
29/36
29/36
59/72
59/72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72
—
—
36
36
72
72

FLA
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.1/173.2
—
—
75.1/ 86.6
75.1/ 86.6
150.1/173.2
150.2/173.2
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
43.3
43.3
86.6
86.6
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3
—
—
34.6
34.6
69.3
69.3

POWER SUPPLY
MCA
252.4/247.0
276.0/270.6
252.4/247.0
276.0/270.6
252.4/247.0
276.0/270.6
267.8/261.0
291.4/284.6
267.8/261.0
291.4/284.6
267.8/261.0
291.4/284.6
281.0/273.0
304.6/296.6
281.0/273.0
304.6/296.6
281.0/273.0
304.6/296.6
119.5
132.1
119.5
132.1
120.4
136.1
126.5
139.1
126.5
139.1
129.1
144.9
132.5
145.1
132.5
145.1
136.6
152.4
101.6
114.2
101.6
114.2
101.6
114.2
106.6
119.2
106.6
119.2
106.6
119.2
111.6
124.2
111.6
124.2
111.6
124.2

MOCP†
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
300/300
350/300
300/300
350/300
300/300
350/300
150
150
150
150
150
150
150
175
150
175
150
175
150
175
150
175
175
175
125
125
125
125
125
125
125
150
125
150
125
150
125
150
125
150
125
150

deviation from average voltage.
5v
7v
2v

Maximum deviation is 7 v.
Determine percent of voltage imbalance.
7

% Voltage Imbalance = 100 x

457
= 1.53%
This amount of phase imbalance is satisfactory as it is below the maximum
allowable 2%.

*Heater capacity (kW) is based on heater voltage of 208 v, 240 v, 480 v, and 575 v.
If power distribution voltage to unit varies from rated heater voltage, heater kW will
vary accordingly.
†Fuse or HACR circuit breaker.

IMPORTANT: If the supply voltage phase imbalance is more than 2%,
contact your local electric utility company immediately.

NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the overcurrent protective device for the
unit shall be fuse or HACR breaker. The Canadian units may be fuse or circuit
breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than
2%. Use the following formula to determine the percent of voltage imbalance.
max voltage deviation from average voltage
% Voltage Imbalance = 100 x
average voltage

3. MCA calculation for units with electric heaters over 50 kW = (1.25 x IFM amps) +
(1.00 x heater FLA).

452 + 464 + 455
3

=

FLA

Determine maximum
(AB) 457 − 452 =
(BC) 464 − 457 =
(AC) 457 − 455 =

LEGEND
Full Load Amps
Heating, Air Conditioning and Refrigeration
Indoor (Evaporator) Fan Motor
Locked Rotor Amps
Minimum Circuit Amps
Maximum Overcurrent Protection
National Electrical Code
Outdoor (Condenser) Fan Motor
Rated Load Amps

EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
Average Voltage =

Hp

POWER
EXHAUST

1371
3

= 457

23

DIP — Dual In-Line Package
PEC − Power Exhaust Controller

Fig. 14 — Control Box Diagram (Sizes 024-034)

DIP — Dual In-Line Package
PEC — Power Exhaust Controller

Fig. 15 — Control Box Diagram (Sizes 038-048)

24

Conductors and drain wire must be 20 AWG minimum
stranded, tinned copper. Individual conductors must be insulated with PVC, PVC/nylon, vinyl, Teflon, or polyethylene. 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.

NOTE: On units running Version 1.0 of
the unit control software, the remote start/
stop switch is connected to R and Y1.

Table 5 — CCN Connection Approved
Shielded Cables
MANUFACTURER
Alpha
American
Belden
Columbia

CABLE PART NO.
2413 or 5463
A22503
8772
02525

IMPORTANT: When connecting the CCN communication bus to a system element, use a color coding system for the entire network to simplify installation and
checkout. See Table 6.
Fig. 16 — Field Control Thermostat Wiring

Table 6 — Color Code Recommendations
SIGNAL
TYPE
Positive (+)
Ground
Negative (−)

NOTE: Sensor part numbers are
as follows:
T55 — HH51BX001
T56 — HH51BX004
T57 — CEC01215303-01

CCN BUS CONDUCTOR
INSULATION COLOR
RED
WHITE
BLACK

CCN PLUG
PIN NO.
1
2
3

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 communication 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
network 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.

Fig. 17 — Field Control Temperature
Sensor Wiring

Remote Field Control (Units Running Version 2.0 of Unit
Control Software) — 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.
Service Tool, Building Supervisor, and Comfort Works —
Access to the control board can be achieved through the terminal marked CCN via a 3-wire bus.
IMPORTANT: Default bus address is 0. Default element number is 1. Refer to CCN literature for information on network addressing or changing CCN communication defaults.

Step 8 — Make Outdoor-Air Inlet Adjustments
ECONOMIZER
NOTE: If accessory power exhaust or barometric relief packages are being added to the unit, install power exhaust or
barometric relief before installing economizer hoods.
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 50EW/EY units are side supply and side return. The return 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 economizer hood.

Carrier Comfort Network Interface — The 50E units can be
connected to the CCN. The communication bus wiring is supplied 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
signal pins must be wired to signal ground pins. Wiring connections for CCN should be made at the 3-pin plug (CCN
located at the base board. Consult CCN literature for further
information.
25

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.
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 1⁄8-in. past the end
opposite the mounting flange. See Fig. 18.
2. Assemble hood sides, top, and cross member with gasketed screws provided. See Fig. 19.
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. 20.
NOTE: Each hood assembly has a slotted side that should
be adjacent to the other hood when mounted to the unit.
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. 21.
6. Add gray foam strip (provided in package) to cross members on bottom tray. See Fig. 22.
7. Place gray foam strip (provided) on inside of slotted hood
side between filter and cross member opposite the mounting end. See Fig. 23.
8. Attach gray foam strip (provided) to block-off baffle on
outer face of flange. See Fig. 24.
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 mounting 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. Locate and mount blockoff baffle using these screws.
12. Assemble 2 filter tracks side-by-side with the assembled ends together.
13. Attach mounting angle (without tabs) to the assembled
end of the filter track. See Fig. 25.
14. Attach 6 green speed clips (provided) to mounting angles.
Engagement section of clip faces inside of rack.

NOTE: Left side economizer hood has mounting angle without tabs and filter
track assembled end on the opposite side.

Fig. 19 — Economizer Hood Assembly
(Right-Side Economizer Hood Shown)

MOUNTING
FLANGE

HOOD SIDE

Fig. 20 — Adding Seal Strip to
Mounting Flange of Hood Sides
15. Attach remaining mounting angle (with tabs) to other
end of the filter track with no. 10 screws provided. See
Fig. 26.
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 gasketed screws provided. Tabs can be hand bent after they
have been inserted into the side.
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 board,
bend the tabs so they will not interfere with installation
of the second 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. 27.
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.

TOP
FLANGE
BLACK
SEAL
STRIP

HOOD SIDE

Fig. 18 — Adding Seal Strip to
Top of Hood Sides
26

HOOD TOP

HOOD SIDE

BLOCKOFF BAFFLE

Fig. 21 — Adding Seal Strip to
Hood Top Mounting Flange

GRAY FOAM STRIP

GRAY FOAM STRIP

Fig. 24 — Adding Foam Strip to Blockoff Baffle
CROSS MEMBER

MOUNTING ANGLE
(WITHOUT TABS)

FILTER TRACK
ASSEMBLY

Fig. 25 — Mounting Angle (Without Tabs)
Attached to Filter Track Assembly

Fig. 22 — Adding Foam Strip to Cross Member

HOOD SIDE
(SLOTTED)
HOOD
TOP

MOUNTING ANGLE
(WITH TABS)

Fig. 26 — Mounting Angle (With Tabs)
Attached to Filter Track Assembly

Fig. 23 — Adding Foam Strip to Hood Side
27

position to go to 10% for 30 seconds, then 20% for 30 seconds, and when it reaches 30% close DIP switch no. 6 during the 30-second period following the 30% position.
The minimum outdoor air damper position is now set.
ECONOMIZER SETTINGS
Accessory Enthalpy Control (Fig. 28) — The control
(HH57AC077) is mounted in the economizer hood. See
Fig. 19. The enthalpy setting adjustment is on the enthalpy
control. For maximum benefit of outdoor air, set enthalpy
control to A. See Fig. 29 and 30.
Accessory Differential Enthalpy Control — The control
(HH57AC077), in conjunction with the accessory enthalpy
sensor (HH57AC078), controls economizer operation according to the differential enthalpy. The control is mounted
in the economizer hood. The sensor is mounted in the return
duct (50EJ/EK) or return air plenum (50EW/EY).

Minimum Damper Position Setting — Setting of the outdoor 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. 6 then
no. 4. See Fig. 17 and Table 7.
The outdoor-air damper closes. The control allows 90 seconds 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. 6 during 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. 6 can be closed. The default value of the minimum outdoor air damper position is
20%. If the desired minimum position is 30%, allow the damper
BLACK SEAL STRIP
(CENTERED)

FILTER COVER

NOTE: Switches shown in high enthalpy state. Terminals 2 and 3 close on enthalpy decrease.

Fig. 29 — Wire Connections for Solid State
Enthalpy Control (HH57AC077)
POINT
CONTROL CONTROL
(APPROX. DEG.)
CURVE
AT 50% RH
A
73 (23)
B
70 (21)
C
67 (19)
D
63 (17)

Fig. 27 — Attaching Seal Strip
to Filter Cover

HH57AC077
ENTHALPY CONTROL

C7400

A1004

+

HH57AC078
ENTHALPY SENSOR
(USED WITH ENTHALPY
CONTROL FOR DIFFERENTIAL
ENTHALPY OPERATION)

RH — Relative Humidity

Fig. 28 — Differential Enthalpy Control
and Sensor

Fig. 30 — Psychrometric Chart for
Enthalpy Control

28

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 located behind the filter access door on the lower inner panel.
See Fig. 32. A section of 1⁄4-in. plastic tubing must be run
from the high-pressure tap on the differential pressure switch
and connected to a tap in the supply-air duct. The tap is usually located 2⁄3 of the way out on the main supply duct. Remove plug button in panel to route tubing.

Step 9 — 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 assembled and tilted back into the unit for shipping. Brackets
and extra screws are shipped in shrink wrap around the dampers. 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. 31. Each damper assembly is secured with 3 screws
on each side and 3 screws along the bottom. Save screws.
2. Pivot each damper assembly outward until edges of damper
assembly rest against inside wall of unit.

VAV BUILDING PRESSURE TRANSDUCER — The VAV
building pressure transducer (modulating power exhaust pressure transducer) is located behind the filter access door on
the inner panel. See Fig. 32. A section of 1⁄4-in. plastic tubing must be run from the high-pressure tap on the differential pressure switch to the conditioned space. The pressure
tube must be terminated in the conditioned space where a
constant pressure is required. This location 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.

Be careful when tilting blower assembly. Hoods
and blowers are heavy and can cause injury if
dropped.
3. Secure each damper assembly to unit with 6 screws across
top (3 screws provided) and bottom (3 screws from
Step 1) of damper.

NOTES:
1. Unless otherwise specified, all dimensions are to outside of part.
2. Dimensions are in inches.

Fig. 31 — Barometric Relief Damper and Power
Exhaust Mounting Details

29

Fig. 33A — Motormaster III Sensor Location
(Sizes 024-034)

VAV — Variable Air Volume

Fig. 32 — Pressure Transducer Locations

Step 10 — Install Accessories — After all the factoryinstalled options have been adjusted, install all fieldinstalled accessories. Refer to the accessory installation instructions included with each accessory.
MOTORMASTERt III SENSOR LOCATION — Motormaster III sensor locations are shown in Fig. 33A-33C. Refer to the Motormaster III installation instructions for wiring
and installation information.

30

Fig. 33C — Motormaster III Sensor Location
(Size 048)

Fig. 33B — MotormasterT III Sensor Location
(Sizes 038 and 044)

31

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 ‘‘SETUP’’ key, then press the ‘‘SETUP’’ key 6 times
to scroll to the sixth parameter, which will display
‘‘Sr1.’’ 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. Open the indoor fan circuit breaker.
8. Replace the jumper between CC and ST on the terminal
strip of the VFD.
9. Close the indoor fan circuit breaker, the VFD now is powered and the fan will operate.
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).

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 applicable codes.
Compressor Mounting — Loosen the compressor holddown 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 compressor could result if they are left closed.
Internal Wiring — Check all electrical connections in
unit control boxes; tighten as required.
Refrigerant Service Ports — Each refrigerant system has one suction port located in the top of the compressor
motor casing. All units also have one service port on the liquid line valve and one on the compressor discharge valve.
Be sure that caps on the ports are tight.

Table 7 — VFD Set Point

Variable Frequency Drive (VFD) — The variable fre-

PRESSURE
(in. wg)
0.00
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

quency drives are factory set. These settings include factoryinstalled jumpers and software configurations. The only
configured set point is duct static pressure. An Operation Manual
is shipped with each VAV unit. This manual should be
used if the drive needs to be customized for a particular
application.
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 2 to 10 vdc,
therefore, 0 to 5 in. wg is proportional to the 2 to 10 vdc and
must be expressed to the VFD in terms of percentage of the
frequency range. To do this, 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 corresponding set point value. If necessary, interpolation
between duct static pressures is permissible.
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 following procedure:
1. Open the indoor fan circuit breaker.
2. Remove the jumper between CC and ST on the terminal
strip of the VFD (see Fig. 34).

VOLTAGE
(vdc)
2.0
2.4
2.8
3.2
3.6
4.0
4.4
4.8
5.2
5.6
6.0
6.4
6.8
7.2
7.6

VFD — Variable Frequency Drive

NOTE: Terminal strip is located inside the VFD (Variable Frequency
Drive) at the bottom.

Fig. 34 — VFD Factory-Installed Jumpers

32

VFD
SET POINT
12.0
14.4
16.8
19.2
21.6
24.0
26.4
28.8
31.2
33.6
36.0
38.4
40.8
43.2
45.6

At the top of the module are 2 potentiometers. The left
potentiometer adjusts the offset. The right potentiometer adjusts differential. The potentiometers are factory set for a
nominal 0 in. wg building pressure.
The offset set point is defined as the point at which a module 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.
Table 8 relates building pressure to signal level.

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,
the base module closes contacts, activating 2 exhaust fans.
When the economizer position reaches 75% open, the base
module activates the other 2 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 singlestage operation is desired, adjust the economizer set points
to identical values at the desired point to activate all exhaust
fans.
The optional modulating power exhaust (VAV standard,
CV optional) is controlled by a modular electronic sequencer system. This system consists of a model R353 signal 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 factoryinstalled hose at the ‘‘Lo’’ connection leads to atmosphere,
and a field-supplied hose must be connected to the ‘‘Hi’’ connection and led into the building to a point where building
pressure is to be controlled. 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 2 pins must be jumpered for
direct operation. Direct operation means that the staging modules are activated in sequence as the input signal
increases.
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 controls. The jumper should be on the middle or bottom 2 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.
The R353 module has a terminal block with 7 connections 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 indication 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).

Table 8 — Potentiometer Signal Levels
BUILDING PRESSURE
(in. wg)
−0.50
−0.25
0.00
0.25
0.50

SIGNAL LEVEL
(vdc)
2
4
6
8
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 exhaust are shown in Table 9.
Table 9 — Power Exhaust Default Set Points
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

OFF
STATIC
PRESSURE
(in. wg)
0.00
0.06
0.12
0.18

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 calibrated in 1% increments, and is factory set at approximately
3%. It is recommended to leave the set point at 3%, to minimize cycling of the fans.
The offset and differential potentioments have been factory set for atmosphereic pressure. Do not change these settings until there is some experience with the building. In most
cases the factory settings will be satisfactory. However, if
the building pressure is not being maintained as desired, then
some minor adjusting on a trial and error basis can be made.

Direct Digital Controls DIP Switch Configuration — The Direct Digital Control (DDC) board must be
configured for each application. The DDC board is configured through the DIP switches located on the board. There
are 8 DIP switches which configure 8 different applications
of the DDC. See Tables 10A and 10B. 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 Tables 11A
and 11B.

33

Table 10A — DIP Switch Configuration (Version 1.0 of Unit Control Software)
SETTING

1

2

3

OPEN

VAV

CCN/
Sensors

Expansion
I/O Board

CLOSED

CV

TSTAT

Base Board
Only

4
Field
Test
ON
Field
Test
OFF

5
Modulated
Power
Exhaust
CV
Power
Exhaust

6
Time Guard Override
ON/ Set Min.
Damper Pos. ON
Time Guard Override
OFF/ Set Min.
Damper Pos. OFF

LEGEND
CCN
CV
I/O
POS.
TSTAT
VAV

—
—
—
—
—
—

7

8

Gas Heat

Factory Test ON

Electric Heat

Factory Test OFF

NOTES:
1. The Factory Test DIP switch should not be enabled in the field.
2. 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.
3. If DIP switch no. 1 is open, DIP switch no. 2 is ignored, since VAV
units control to supply-air temperature.

Carrier Comfort Network
Constant Volume
Input/Output
Position
Thermostat
Variable Air Volume

Table 10B — DIP Switch Configuration (Version 2.0 of Unit Control Software)
SETTING

1

2

3

4

VAV — Space Sensor
Installed
OPEN

VAV

Expansion
Board

Field Test
ON

Base Control
Board Only

Field Test
OFF

CV — CCN or Sensors
Used

VAV — No Space Sensor
CLOSED

CV
CV — Thermostat

5
VAV —
Occupied
Heat
Enabled
CV —
Modulated
Power
Exhaust
VAV —
Occupied
Heat
Disabled
CV —
Constant
Volume
Power
Exhaust

LEGEND

6

7

8

Gas Heat

Heat Pump
Operation

Electric Heat

Air Conditioner
Operation

Time Guard Override
ON
IN CONJUNCTION
WITH FIELD TEST
— Set Minimum
Damper Position

Time Guard Override
OFF

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.
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 CV 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.

CCN — Carrier Comfort Network
CV
— Constant Volume
VAV — Variable Air Volume

Table 11A — DIP Switch Factory Settings (Version 1.0 of Unit Control Software)
UNIT
50EJ/EW
50EK/EY

1
Closed
Open

2
Closed
Closed

3
Closed
Closed

4
Closed
Closed

5
Closed
Open

6
Closed
Closed

7
Closed
Closed

8
Closed
Closed

Table 11B — DIP Switch Factory Settings (Version 2.0 of Unit Control Software)
UNIT
50EJ/EW
50EK/EY

1
Closed
Open

2
Closed
Closed

3
Closed
Closed

4
Closed
Closed

34

5
Closed
Closed

6
Closed
Closed

7
Closed
Closed

8
Closed
Closed

DIP switch configurations for Version 1.0 of the Unit Control Software are as follows:
• DIP switch 1 configures the unit to operate as a variable
air volume (VAV) or constant volume (CV) unit
• DIP switch 2 configures what type of sensors or thermostats are used with the unit
• DIP switch 3 configures the DDC for use with the electronic expansion board
• DIP switch 4 is used to field test the unit
• DIP switch 5 configures the unit to use constant volume or
modulated power exhaust
• DIP switch 6 configures the Time Guardt override and the
minimum damper position
• DIP switch 7 configures the unit for gas heat or electric
heat
• DIP switch 8 is used to factory test the unit
The DIP switch configurations for Version 2.0 of the unit
control software 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)
• DIP switch 3 configures the DDC for use with an electronic 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 Guard override and, when
used with the field test function, sets the minimum damper
position
• DIP switch 7 configures the unit for gas heat or electric
heat
• DIP switch 8 configures the unit for heat pump or air conditioner operation

Filter Replacement — To replace filters, open filter
access door (marked with label). Remove inner access panel.
Remove plastic filter retainer in between filter tracks by sliding 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 removal tool to remove the remaining filters.
Outdoor-Air Inlet Screens — Outdoor-air inlet screens
must be in place before operating unit.
Economizer Adjustment — Remove filter access panel.
Check that outdoor-air damper is closed and return-air damper
is open.
Economizer operation and adjustment is described in Sequence of Operation and Make Outdoor Air Inlet Adjustments sections (this page and page 25), respectively.
Sequence of Operation
NOTE: Unit is shipped with default values that can be changed
through Service Tool or CCN software.
COOLING, CONSTANT VOLUME (CV) UNITS — On
power up, the control module will activate the initialization
software. The initialization software 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 TSTAT or sensor
type operation. The initialization sequence: clears all alarms
and alerts; re-maps the input/output database for CV operation; sets maximum heat stages to 2; and sets maximum cool
stages to 3. The control module reads DIP switch no. 3 and
determines if the unit will use expansion mode operation.
The TSTAT function performs a thermostat based control
by monitoring Y1, Y2, W1, W2 and G inputs. These functions control stages: cool1, cool2, heat1, heat2, and the indoor fan respectively. If the TSTAT function is not selected,
the control module determines the occupancy state based on
the system time schedules or with remote occupied/unoccupied
input. If Temperature Compensated Start is active, the unit
will be controlled as in the Occupied mode. User defined set
points are shown in Table 17.
Occupied or unoccupied comfort set points must be selected. Use of the space temperature offset input can also be
configured. The control module will set appropriate operating mode and fan control. The control module will turn on
indoor fan if in Occupied mode or if the unit is in Unoccupied mode and the space temperature is outside of the unoccupied comfort set points (Unoccupied Heat or Unoccupied Cool). The control module will then monitor space
temperature against comfort set points and control heating
or cooling stages as required. If the system is in the Occupied mode, the economizer will operate as required. If the
system is in Unoccupied mode, the system will perform night
time free cool and IAQ (indoor air quality) pre-occupancy
purge as required (when functions are enabled via software).
Whenever the DX (direct expansion) cooling is requested,
the outdoor fan will operate.

Crankcase Heater(s) — Heater(s) is energized 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.

Evaporator Fan — Fan belt and fixed pulleys are factoryinstalled. See Tables 12-14 for Fan Performance Data. See
Table 15 for Air Quantity Limits. See Table 16 for Motor
Limitation data. Be sure that fans rotate in the proper direction. Static pressure drop for power exhaust, barometric
relief damper, and electric heat is negligible. To alter fan performance, see Evaporator Fan Performance Adjustment section on page 43.

Condenser Fans and Motors — Fans and motors
are factory set. Refer to Condenser-Fan Adjustment section
(page 44) as required.
Return-Air Filters — Check that correct filters are installed in filter tracks. See Table 1. Do not operate unit without return-air filters.

35

Table 12 — Fan Performance, 50EJ/EK024-034 — Vertical Discharge Units
FOR EW/EY UNITS, REDUCE NET AVAILABLE EXTERNAL STATIC PRESSURE BY 0.3 IN. WG
AIRFLOW
(Cfm)
4,000
5,000
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

AIRFLOW
(Cfm)
4,000
5,000
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

AIRFLOW
(Cfm)
4,000
5,000
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

0.2
Rpm
322
361
403
448
495
507
543
592
642
693
718
744
783
795
847

Bhp
0.77
1.14
1.62
2.22
2.97
3.18
3.85
4.90
6.10
7.48
8.23
9.03
10.32
10.77
12.71

0.4
Rpm
401
433
468
508
549
560
593
638
685
733
757
781
818
831
880

1.8
Rpm
746
764
785
809
836
843
865
897
931
967
985
1004
1033
1043
1083

Bhp
3.64
4.21
4.89
5.70
6.65
6.91
7.74
8.98
10.37
11.94
12.78
13.67
15.09
15.59
17.70

Bhp
1.09
1.50
2.01
2.65
3.42
3.64
4.34
5.41
6.64
8.04
8.80
9.62
10.92
11.38
13.34

2.0
Rpm
783
800
820
843
869
876
898
928
961
996
1014
1032
1060
1070
1109

Bhp
4.03
4.62
5.32
6.16
7.12
7.39
8.23
9.49
10.91
12.49
13.35
14.25
15.69
16.19
18.32

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
0.6
0.8
1.0
1.2
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
466
1.43
523
1.78
575
2.13
622
2.50
494
1.86
548
2.23
598
2.62
643
3.00
526
2.41
577
2.81
624
3.21
668
3.62
561
3.08
609
3.50
654
3.93
696
4.37
599
3.88
645
4.33
687
4.79
727
5.25
609
4.10
654
4.56
696
5.02
735
5.49
639
4.82
682
5.30
723
5.78
761
6.27
682
5.91
722
6.42
760
6.93
797
7.44
725
7.17
764
7.70
800
8.24
835
8.77
771
8.60
807
9.15
841
9.71
874 10.26
794
9.37
829
9.94
862 10.51
895 11.08
817 10.20
851 10.78
884 11.36
915 11.93
852 11.52
885 12.12
917 12.71
947 13.31
864 11.98
896 12.59
928 13.19
958 13.79
912 13.96
943 14.59
972 15.21 1001 15.83

Rpm
666
686
709
736
765
773
797
832
868
906
926
946
977
987
1029

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
2.2
2.4
2.6
2.8
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
818
4.44
852
4.85
884
5.26
916
5.68
834
5.04
868
5.46
900
5.89
930
6.33
854
5.76
886
6.21
918
6.65
948
7.11
876
6.61
908
7.08
939
7.54
968
8.01
901
7.60
932
8.08
962
8.57
991
9.05
908
7.87
938
8.36
968
8.84
997
9.34
929
8.73
959
9.23
988
9.74 1016 10.24
958 10.01
987 10.53 1016 11.06 1043 11.58
990 11.45 1018 11.99 1046 12.54 1073 13.08
1024 13.06 1051 13.62 1078 14.18 1104 14.75
1041 13.92 1068 14.49 1094 15.07 1120 15.64
1059 14.83 1086 15.42
1111 16.00 1137 16.59
1087 16.29 1112 16.88 1138 17.48 1162 18.08
1096 16.79 1122 17.40 1147 18.00 1171 18.60
1134 18.94 1159 19.56 1183 20.19
—
—

Rpm
946
960
977
997
1019
1025
1043
1070
1099
1129
1145
1161
1186
1195
—

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
3.4
3.6
3.8
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
1004
6.97
1032
7.41
1059
7.86
1017
7.67
1045
8.12
1072
8.58
1034
8.49
1061
8.96
1087
9.43
1052
9.44
1079
9.93
1105
10.42
1073
10.54
1099
11.04
1125
11.55
1079
10.84
1105
11.34
1130
11.85
1096
11.78
1122
12.30
1147
12.82
1122
13.18
1147
13.71
1171
14.25
1149
14.73
1173
15.29
1197
15.84
1178
16.45
1202
17.03
—
—
1193
17.38
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—

1.4
Bhp
2.87
3.40
4.04
4.81
5.71
5.96
6.76
7.95
9.30
10.82
11.64
12.51
13.90
14.39
16.45

1.6
Rpm
707
726
748
773
801
809
832
865
900
937
956
975
1005
1015
1056

3.0
Bhp
6.11
6.77
7.56
8.49
9.55
9.83
10.75
12.11
13.63
15.31
16.22
17.17
18.68
19.21
—

Bhp
3.25
3.80
4.46
5.25
6.18
6.43
7.24
8.46
9.84
11.38
12.21
13.09
14.50
14.99
17.08

3.2
Rpm
975
989
1006
1025
1046
1052
1070
1096
1124
1154
1169
1185
—
—
—

Bhp
6.54
7.22
8.02
8.96
10.04
10.33
11.27
12.64
14.18
15.88
16.80
17.76
—
—
—

LEGEND
Bhp — Brake Horsepower
NOTES:
1. Fan performance is based on wet coils, economizer, roof curb,
cabinet losses, and clean 2-in. filters.
2. Conversion — Bhp to watts:
Bhp x 746
Watts =
Motor efficiency
3. VAV units will operate down to 70 cfm/ton.

36

Table 13 — Fan Performance, 50EJ038,044 and 50EK044 — Vertical Discharge Units
For EW/EY UNITS, REDUCE NET AVAILABLE EXTERNAL STATIC PRESSURE BY 0.5 IN. WG
AIRFLOW
(Cfm)
8,000
9,000
10,000
11,000
12,000
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

AIRFLOW
(Cfm)
8,000
9,000
10,000
11,000
12,000
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

AIRFLOW
(Cfm)
8,000
9,000
10,000
11,000
12,000
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

0.2
Rpm
448
492
537
582
629
675
722
770
817
865
913
961
1009

Bhp
2.18
2.87
3.69
4.65
5.75
7.00
8.42
10.00
11.76
13.70
15.83
18.16
20.69

0.4
Rpm
498
537
578
620
664
708
753
798
844
890
937
984
1031

1.8
Rpm
783
803
827
854
883
914
948
983
1019
1057
1096
1135
1176

Bhp
5.70
6.66
7.77
9.03
10.45
12.05
13.83
15.80
17.96
20.33
22.91
25.72
28.75

Bhp
2.87
3.68
4.63
5.75
7.02
8.48
10.11
11.94
13.96
16.19
18.64
21.32
24.22

2.0
Rpm
818
836
858
884
911
942
974
1007
1043
1079
1117
1156
1196

Bhp
6.13
7.11
8.23
9.51
10.96
12.57
14.37
16.36
18.54
20.93
23.53
26.36
29.41

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
0.6
0.8
1.0
1.2
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
544
3.25
589
3.64
631
4.04
671
4.44
580
4.09
621
4.50
660
4.92
698
5.35
617
5.07
655
5.50
692
5.95
727
6.39
657
6.20
692
6.66
726
7.13
759
7.60
698
7.50
730
7.98
763
8.47
794
8.96
739
8.98
770
9.48
800
9.99
830 10.50
782 10.63
811 11.16
840 11.69
868 12.22
826 12.48
853 13.03
880 13.57
907 14.13
870 14.53
896 15.09
922 15.66
947 16.23
915 16.78
940 17.37
964 17.95
988 18.54
961 19.25
984 19.85 1007 20.46 1030 21.07
1006 21.94 1029 22.56 1050 23.19 1072 23.82
1052 24.86 1074 25.50 1095 26.15 1115 26.80

Rpm
710
734
761
792
824
859
895
932
971
1011
1052
1093
1136

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
2.2
2.4
2.6
2.8
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
852
6.56
884
7.00
916
7.45
947
7.90
869
7.56
900
8.02
930
8.48
960
8.95
889
8.70
919
9.18
948
9.66
977 10.15
913 10.00
941 10.50
969 11.00
997 11.50
939 11.47
967 11.98
993 12.50 1020 13.02
968 13.10
994 13.63 1020 14.17 1045 14.71
999 14.92 1024 15.47 1049 16.02 1073 16.58
1032 16.92 1056 17.49 1079 18.06 1102 18.64
1066 19.13 1089 19.71
1111 20.30 1134 20.89
1102 21.53 1124 22.14 1145 22.75 1167 23.35
1138 24.15 1160 24.78 1180 25.40
—
—
1176 26.99 1197 27.63
—
—
—
—
—
—
—
—
—
—
—
—

Rpm
978
989
1005
1024
1046
1070
1096
1125
1156
1188
—
—
—

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
3.4
3.6
3.8
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
1036
9.29
1065
9.76
1092
10.24
1046
10.38
1073
10.87
1100
11.36
1059
11.63
1086
12.13
1112
12.64
1076
13.03
1102
13.55
1127
14.07
1096
14.60
1121
15.13
1145
15.67
1118
16.34
1142
16.89
1165
17.45
1143
18.26
1166
18.83
1188
19.40
1170
20.37
1192
20.96
—
—
1199
22.68
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—

1.4
Bhp
4.86
5.78
6.85
8.07
9.45
11.01
12.75
14.68
16.81
19.14
21.68
24.45
27.45

1.6
Rpm
747
769
795
823
854
887
922
958
995
1034
1074
1115
1156

3.0
Bhp
8.36
9.42
10.64
12.01
13.54
15.25
17.14
19.21
21.49
23.97
—
—
—

Bhp
5.27
6.22
7.30
8.55
9.95
11.53
13.29
15.24
17.38
19.73
22.30
25.08
28.10

3.2
Rpm
1007
1018
1032
1050
1071
1094
1120
1148
1177
—
—
—
—

Bhp
8.82
9.90
11.13
12.52
14.07
15.79
17.70
19.79
22.08
—
—
—
—

LEGEND
Bhp — Brake Horsepower
NOTES:
1. Fan performance is based on wet coils, economizer, roof curb,
cabinet losses, and clean 2-in. filters.
2. Conversion − Bhp to watts:
Bhp x 746
Watts =
Motor efficiency
3. VAV units will operate down to 70 cfm/ton.

37

Table 14 — Fan Performance, 50EJ048 — Vertical Discharge Units
FOR EW UNITS, REDUCE NET AVAILABLE EXTERNAL STATIC PRESSURE BY 0.5 IN. WG
AIRFLOW
(Cfm)
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

AIRFLOW
(Cfm)
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

AIRFLOW
(Cfm)
13,000
14,000
15,000
16,000
17,000
18,000
19,000
20,000

0.2
Rpm
683
730
778
826
875
923
972
1021

Bhp
7.10
8.53
10.14
11.93
13.90
16.06
18.42
20.98

0.4
Rpm
715
761
807
853
900
947
995
1042

1.8
Rpm
921
955
991
1028
1066
1106
1146
1187

Bhp
12.18
13.98
15.98
18.17
20.58
23.19
26.04
29.11

Bhp
8.59
10.25
12.10
14.15
16.42
18.90
21.61
24.55

2.0
Rpm
948
981
1015
1051
1089
1127
1166
—

Bhp
12.71
14.53
16.54
18.76
21.18
23.82
26.68
—

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
0.6
0.8
1.0
1.2
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
747
9.09
777
9.60
808 10.11
837 10.62
790 10.77
819 11.30
847 11.83
875 12.36
834 12.65
862 13.19
888 13.75
915 14.30
879 14.72
905 15.29
931 15.86
955 16.44
925 17.01
949 17.60
973 18.19
997 18.78
971 19.51
994 20.12 1017 20.73 1039 21.34
1017 22.24 1039 22.87 1061 23.50 1083 24.13
1064 25.20 1085 25.85 1106 26.50 1126 27.15

Rpm
866
902
941
980
1020
1062
1104
1147

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
2.2
2.4
2.6
2.8
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
975 13.24 1001 13.77 1026 14.30 1051 14.84
1006 15.08 1031 15.63 1056 16.18 1080 16.74
1040 17.11 1063 17.68 1087 18.25 1110 18.83
1074 19.34 1097 19.93 1120 20.52 1142 21.12
1111 21.78 1133 22.39 1154 23.00 1175 23.61
1148 24.44 1169 25.07 1190 25.69
—
—
1187 27.32
—
—
—
—
—
—
—
—
—
—
—
—
—
—

Rpm
1076
1103
1133
1164
1197
—
—
—

1.4
Bhp
11.14
12.90
14.86
17.01
19.38
21.96
24.76
27.80

1.6
Rpm
894
929
966
1004
1043
1084
1125
1167

3.0
Bhp
15.39
17.30
19.41
21.71
24.23
—
—
—

Bhp
11.66
13.44
15.42
17.59
19.98
22.58
25.40
28.46

3.2
Rpm
1100
1127
1155
1185
—
—
—
—

Bhp
15.93
17.86
19.99
22.31
—
—
—
—

LEGEND
Bhp — Brake Horsepower

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)
3.4
3.6
3.6
Rpm
Bhp
Rpm
Bhp
Rpm
Bhp
1124
16.48
1148
17.03
1171
17.59
1150
18.43
1173
19.00
1195
19.57
1177
20.57
1199
21.16
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—

NOTES:
1. Fan performance is based on wet coils, economizer, roof curb,
cabinet losses, and clean 2-in. filters.
2. Conversion − Bhp to watts:
Bhp x 746
Watts =
Motor efficiency
3. VAV units will operate down to 70 cfm/ton.

Table 15 — Air Quantity Limits
UNIT
50EJ,EK,EW,EY
024
028
030
034
038
044
048

MINIMUM HEATING
CFM
6,000
7,500
8,250
9,000
10,500
12,000
13,500

MINIMUM COOLING
CFM (VAV)
2000
2500
2750
3000
3500
4000
4500

LEGEND
CV — Constant Volume
VAV — Variable Air Volume

38

MINIMUM COOLING
CFM (CV)
6,000
7,500
8,250
9,000
10,500
12,000
13,500

MAXIMUM
CFM
10,000
12,500
13,750
15,000
17,500
20,000
22,500

Table 16 — Motor Limitations
STANDARD EFFICIENCY MOTORS
Nominal
Hp

Maximum
Bhp
5.9
5.9
8.7
9.5
10.2
11.8
15.3
18.0
22.4
23.4
28.9
29.4
35.6
34.7

5
7.5
10
15
20
25
30

208
17.94
—
25.52
—
26.93
—
42.84
—
59.36
—
76.30
—
92.56
—

Maximum Amps
230
460
16.99
—
—
8.50
24.36
—
—
13.30
25.50
—
—
14.75
40.80
—
—
24.00
56.00
—
—
29.25
72.83
—
—
37.04
87.81
—
—
42.80

575
—
5.78
—
9.63
—
11.33
—
18.00
—
22.82
—
28.69
—
n/a

208
16.76
—
—
26.10
—
—
28.56
—
—
45.08
—
—
63.84
—
—
80.69
—
—
102.65
—
—

Maximum Amps
230
460
13.92
—
—
6.96
—
—
22.27
—
—
12.16
—
—
24.89
—
—
14.40
—
—
39.17
—
—
23.04
—
—
55.55
—
—
29.02
—
—
70.05
—
—
35.63
—
—
89.00
—
—
43.38
—
—

575
—
—
5.66
—
—
9.50
—
—
11.68
—
—
18.12
—
—
23.17
—
—
28.81
—
—
33.89

Maximum
Watts

Motor
Efficiency

5,348
5,240
7,717
8,549
8,879
10,284
13,686
15,891
19,032
19,950
24,499
25,181
29,378
29,316

82.3
84.0
84.1
82.9
85.7
85.6
83.4
84.5
87.8
87.5
88.0
87.1
90.4
88.3

Maximum
Watts

Motor
Efficiency

5,030
5,030
4,918
7,334
8,008
7,728
8,502
9,836
9,600
12,543
14,756
14,439
18,363
19,183
18,650
23,511
23,918
23,432
28,742
28,015
27,656

87.5
87.5
89.5
88.5
88.5
91.7
89.5
89.5
91.0
91.0
91.0
93.0
91.0
91.0
93.6
91.7
91.7
93.6
92.4
92.4
93.6

HIGH EFFICIENCY MOTORS
Nominal
Hp

Maximum
Bhp

5

7.5

10

15

20

25

30

5.9
5.9
5.9
8.7
9.5
9.5
10.2
11.8
11.8
15.3
18.0
18.0
22.4
23.4
23.4
28.9
29.4
29.4
35.6
34.7
34.7

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.

LEGEND
BHP — Brake Horsepower

Table 17 — User Defined Set Points
SET POINT
OHSP
OCSP
UHSP
UCSP
SASP
OATL
NTLO
RTIO
LIMT
MDP
IAQS
UHDB
UCDB
LTMP
HTMP
PES1
PES2

FORMAT
xx.xF
xx.xF
xx.xF
xx.xF
xx.xF
xx.xF
xx.xF
xx.x
xx.x^F
xxx%
xxxx
xx.x^F
xx.x^F
xx.xF
xx.xF
xx.xF
xx.xF

DESCRIPTION
Occupied Heat Set Point
Occupied Cool Set Point
Unoccupied Heat Set Point
Unoccupied Cool Set Point
Supply Air Set Point
Hi OAT Lockout Temperature
Unoccupied OAT Lockout Temperature
Reset Ratio
Reset Limit
Minimum Damper Position
IAQ Set Point
Unoccupied Heating Deadband
Unoccupied Cooling Deadband
Low Temp. Min. Position
High Temp. Min. Position
CV Power Exhaust Stage 1 Point
CV Power Exhaust Stage 2 Point

LEGEND
CV
— Constant Volume
IAQ — Indoor Air Quality
OAT — Outdoor Air Temperature

39

LIMITS
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
0 to 20 F
0 to 100%
1 to 5000
0 to 10
0 to 10
0 to 100
0 to 100
0 to 100
0 to 100

DEFAULT
68
78
55
90
55
65
50
3
10
20
650
1
1
10
35
25
75

The control module will operate economizer, run diagnostics 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/
outdoor-air temperature broadcast and global occupancy broadcast. When the optional expansion I/O board is employed, it
will: perform a periodic scan and maintain a database of expanded I/O points; perform Fire/Smoke control (power exhaust required); if in Occupied mode, perform IAQ control
and monitor the fan, filter, demand limit, and field-applied
status (with accessories).
If thermostats are used to energize the G input, the control
module will turn on the indoor fan without delay and open
the economizer dampers to minimum position. If thermostats are used to deenergize the G input, the control module
will turn off the indoor fan without delay and close the economizer dampers.
When cooling, G must be energized before cooling can
operate. The control module determines if outdoor conditions are suitable for economizer cooling using the standard
outdoor air thermistor. For the economizer to function for
outside air cooling: the enthalpy must be below the enthalpy
set point; the outdoor-air temperature must be equal to or
less than the High Outdoor Air Temperature Lockout (default is 65 F); the SAT (supply-air temperature) thermistor
must not be in alarm; and the outdoor air reading is available. When these conditions are satisfied, the control module will use economizer as the first stage of cooling.
When Y1 input is energized, the economizer will be modulated 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
economizer will modulate between minimum and 100% open
position. When Y2 is energized, the control module will turn
on compressor 1 and continue to modulate the economizer
as described above. If the Y2 remains energized and the SAT
reading remains above the set point for 15 minutes, compressor 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 cooling, the economizer will go to minimum position and cycle
compressors 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 1 and
less than 45 F for compressor 2). After a compressor is locked
out, it can restart after normal time-guard period.
The Time Guardt function 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 operate
simultaneously.
COOLING, VARIABLE VOLUME UNITS — On power up,
the control module will activate the initialization software.
The initialization software reads DIP switch no. 1 position
to determine CV or VAV operation. The initialization sequence: 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 module
reads DIP switch no. 3 and determines if the unit will use
expansion mode operation. Power up takes a random time of
1 to 63 seconds plus 5 minutes the first time power is sent
to the control board after a power outage.
The control module 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 a linkage is active, the
control module will replace local comfort set points, space
and return air temperatures, and occupancy status with the
linkage data supplied.
The control module will determine occupancy status from
Time Schedules (if programmed), Remote Occupied/
Unoccupied input, global occupancy schedules, or DAV. If
temperature 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 in Unoccupied mode to
reach the occupied set point when occupancy occurs.
The control module will set the appropriate operating mode
and fan control. The control module will turn on the VFD if
Occupied mode is evident. If in Unoccupied mode and a valid
space temperature reading is available (either from a sensor
or DAV), the control module will monitor SPT (space temperature) against unoccupied heat and cool set points. The
control module 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 the VFD is running in a normal mode, the control module will start heating or cooling
as required 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 reset is only available when enabled through software.
When cooling, the control module will energize the power
exhaust enable output to the external power exhaust controller (when power exhaust is used).
The control module will run continuous diagnostics for
alarms/alerts; respond to CCN (Carrier Comfort Network)
communications; perform any configured network POC (Product Outboard Control) functions such as time/outdoor air temperature broadcast and global broadcast; and perform Fire/
Smoke control.
HEATING, CONSTANT VOLUME (CV) UNITS — The
control module is powered by 24 vac. If the unit is controlled with a room sensor, the fan will run continuously in
the Occupied mode, with the outside-air damper in the minimum position. If the unit is controlled through a room thermostat (with FAN set to AUTO), upon a call for heat the first
stage of heat is energized, the indoor-fan motor will turn on,
and the outdoor-air damper will move to the minimum position. Upon a call for additional heat (if the unit is equipped
with a two-stage heater), the second stage of heat is energized. When the call for heat is satisfied, the heaters will
deenergize. The indoor-fan motor will also deenergize (unless controlled by a room sensor) and the outdoor-air damper
will move to the closed position.
If the unit is controlled with a room sensor the fan will not
run in the unoccupied mode. Upon a call for heat, the first
stage of heat is energized, the indoor-fan motor will turn on,
and the outdoor air damper will move to the Unoccupied
IAQ position (generally set to zero in the unoccupied mode).
The IAQ feature is enabled through system software. Upon
a call for additional heat (if the unit is equipped with a twostage heater), the second stage of heat is energized. When
the call for heat is satisfied, the heaters and indoor-fan motor
will deenergize and the outdoor-air damper will move to the
closed position (if open).
HEATING, VARIABLE AIR VOLUME (VAV) UNITS —
The control board is powered by 24 vac. When there is a call
for heating (from Morning Warm-Up, Unoccupied, or Occupied modes), power is sent from the control module to
energize the first stage of electric heat. A field-supplied heat

40

interlock relay signals for the air terminals to fully open. See
Fig. 35. In the Occupied mode, the indoor-fan motor will
operate continuously and the outdoor-air dampers will be in
the minimum position. In the Unoccupied mode, the indoorfan motor will be off, but will energize upon the call for heat.
The outdoor-air dampers will move to the IAQ unoccupied
position (generally set to zero in the Unoccupied mode). The
IAQ feature is enabled through system software. The duct
pressure sensor will signal to the variable frequency drive to
operate at full speed. Upon a call for additional heat (if the
unit is equipped with a two-stage heater), the second stage
of heat will be energized. When the call for heat is satisfied,
the heaters will deenergize.
NOTE: The HIR is not needed in a DAV system.
If the unit is in the Unoccupied mode, the indoor-fan motor will deenergize and the outdoor-air damper will move to
the closed position (if open).
MORNING WARM-UP (VAV ONLY WITH PC ACCESSED/
CCN OPERATION) — Morning warm-up occurs when the
control module has been programmed to turn on heat, prior
to the Occupied mode, to be ready for the occupancy. Morning warm-up is a condition in VAV systems that occurs when
the Temperature Compensated Start algorithm calculates a
biased occupied 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 continue heating into the occupied period, even if occupied heating is disabled. When the heating demand is satisfied, the warm-up condition will terminate. To increase or
decrease the heating demand, use the network access software to change the occupied heating set point.
NOTE: To utilize morning warm-up mode, the unit occupancy schedule must be accessed via Service Tool, Comfort
Works, or Building Supervisor software (units running Version 1.0 of unit control software).
MORNING WARM-UP (VAV ONLY WITH STAND-ALONE
OPERATION) — When a unit running version 2.0 of the
unit control software operates in stand-alone mode, morning
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 interlock 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. 35 for heat interlock relay wiring.
SPACE TEMPERATURE RESET (VAV ONLY) — An accessory space temperature sensor is required. Space temperature 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 temperature falls below the cool set point, the supply-air temperature will be reset upward as a function of the reset ratio. Reset ratio is expressed in degrees change in supply-air temperature
per degree of space temperature change. A reset limit will
exist which will limit the maximum number of degrees the
supply-air temperature may be raised. 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
in Occupied mode.
3. If the system is in Occupied mode, 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.

The field-supplied space temperature sensor input signal
(4 to 20 ma and 2 to 10 vdc) enables the space temperature
reset function. Refer to Fig. 36 for sensor wiring.
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 (only offered with constant volume units) and modulating power exhaust (offered
on VAV units) are the 2 packages available. The modulating
power exhaust package is equipped with a field-adjustable
static pressure controller which will control up to 4 power
exhaust stages to maintain a building static pressure. The blue
sequencer 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 pressure. The standard power
exhaust package controls up to 2 stages of power exhaust to
maintain building pressure. These power exhaust stages are
staged according to a percentage of the economizer damper
position. The default values are 25% for Stage 1 and 75%
for Stage 2. This package has set points that are adjustable
through software (such as Service Tool, Building Supervisor, or Comfort Works).

Fig. 35 — Heat Interlock Relay Wiring

Fig. 36 — Space Temperature Sensor Wiring

41

MOTORMASTERt III DEVICE — The Motormaster III
Solid-State Head Pressure Control is a field-installed accessory, fan speed control device actuated by a temperature sensor. The Motormaster III device is specifically designed for
use on Carrier equipment and controls the outdoor-fan motor speed in response to the saturated condensing temperature. For outdoor temperatures down to −20 F, the Motormaster III device maintains condensing temperature at
100 F.

CAPACITY CONTROL, COOLING — The cooling capacity staging tables are shown in Tables 18 and 19.
Table 18 — Cooling Capacity Staging Table
CV Units with 2 Compressors
STAGES

0

Compressor 1
Compressor 2

Off
Off

1
ECONOMIZER
Off
Off

2

3

On
Off

On
On

NOTE: On CV units that require additional unloading, add suction pressure unloaders on Compressor 1 only.

SERVICE

Table 19 — Cooling Capacity Staging Table
VAV Units with 2 Compressors
and 2 Unloaders*
STAGES
Compressor 1
Unloader 1
Unloader 2
Compressor 2

0
Off
Off
Off
Off

1
On
On
On
Off

2
On
On
Off
Off

3
On
Off
Off
Off

4
On
On
On
On

5
On
On
Off
On

Before performing service or maintenance operations on
unit, turn off main power switch to unit. Turn off accessory heater power switch if applicable. Electrical shock
could cause personal injury.

6
On
Off
Off
On

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.
Each door is held closed with 3 latches. The latches are
secured to the unit with a single 1⁄4-in. - 20 x 1⁄2-in. long bolt.
See Fig. 37.
To open, loosen the latch bolt using a 7⁄16-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 replacement of the top cover onto the unit and prevent rainwater
from leaking into the unit.

*40 ton units have only 1 unloader.

FIELD TEST — The field test program is initiated by moving up DIP switch no. 4 to the OPEN position. The outdoorair 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 outsideair damper will begin to open to its default value of 20% and
stay at that position for a short period of time. The outdoorair 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.
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.
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.
The field test is then complete.
TIME GUARDt CIRCUIT — The Time Guard function (built
into the rooftop’s control module board) maintains a minimum off time of 5 minutes and a minimum on time of
10 seconds.
CRANKCASE HEATER — The unit main power supply must
remain on to provide crankcase heater operation. The crankcase heater in each compressor keeps oil free of refrigerant
while compressor is off.
HEAD PRESSURE CONTROL — Each unit has a fan cycling, outdoor thermostat to shut off outdoor-fan motor(s) at
55 F (one outdoor-fan motor on 024-034 units and 2 outdoorfan motors on 038-048 units). The head pressure control permits the unit to operate with correct condensing temperatures
down to 35 F outdoor-air temperature.

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.

Fig. 37 — Door Latch

42

CONDENSER AND EVAPORATOR-FAN MOTOR BEARINGS — The condenser and evaporator-fan motors have
permanently-sealed bearings, so no field lubrication is
necessary.

Cleaning — Inspect unit interior at beginning of each heating and cooling season and as operating conditions require.
Remove unit top panel and/or side panels for access to unit
interior.
EVAPORATOR COIL — Clean as required with a 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 require. Refer to Table 1 for type and size.
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 throwaway filters in place of screens.

Evaporator Fan Performance Adjustment
(Fig. 38) — Fan motor pulleys are factory set for speed
shown in Table 1 (factory speed setting).
To change fan speeds, change pulleys.
To align fan and motor pulleys:
1. Shut off unit power supply.
2. Loosen fan shaft pulley bushing.
3. Slide fan pulley along fan shaft.
4. Make angular alignment by loosening motor from mounting plate.
5. Retighten pulley.
IMPORTANT: Check to ensure that the unit drive
matches the duct static pressure in Tables 12 to 14.

Evaporator Fan Service and Replacement
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

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
between 1⁄4 and 1⁄3 of sight glass during steady operation.
If oil charge is above 1⁄3 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

Turn off unit power.
Remove supply-air section panels.
Remove belt and blower pulley.
Loosen set screws in blower wheels.
Remove locking collars from bearings.
Remove shaft.
Remove venturi on opposite side of bearing.
Lift out wheel.
Reverse above procedure to reinstall fan.
Check and adjust belt tension as necessary.

IMPORTANT: Do not use reclaimed oil or oil that has
been exposed to the atmosphere. Refer to Carrier Standard Service Techniques Manual, Chapter 1, Refrigerants section, for procedures to add or remove oil.
FAN SHAFT BEARINGS — Lubricate the bearings at least
twice annually with suitable bearing grease. Do not over grease.
Typical lubricants are show below:
MANUFACTURER
Texaco
Mobil
Sunoco
Texaco

LUBRICANT
Regal AFB-2*
Mobilplex EP No. 1
Prestige 42
Multifak 2

Fig. 38 — Evaporator-Fan Pulley Alignment
and Adjustment

*Preferred lubricant because it contains rust and oxidation inhibitors.

43

3. Fully retract motor plate adjusting bolts.
4. Loosen the 2 rear (nearest the evaporator coil) motor
plate nuts.
5. Remove the 2 front motor plate nuts and carriage bolts.
6. Slide motor plate to the rear (toward the coil) and remove 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 allow 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.

Belt Tension Adjustment — To adjust belt tension:
1.
2.
3.
4.

Remove power to unit.
Remove motor mount nuts and bolts.
Loosen fan motor nuts. See Fig. 39.
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.
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.

Condenser-Fan Adjustment
1.
2.
3.
4.

Shut off unit power supply.
Remove fan guard.
Loosen fan hub setscrews.
Adjust fan height on shaft using a straightedge placed across
venturi and measure per Fig. 40.
5. Tighten setscrews and replace fan guard.
6. Turn on unit power.

Power Failure — Dampers have a spring return. In event
of power failure, dampers will return to fully closed position
until power is restored.
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 during charging procedure.
NO CHARGE — Use standard evacuating techniques. After
evacuating system, weigh in the specified amount of refrigerant (refer to Table 1).

Evaporator-Fan Motor Replacement
1. Shut off unit power supply.
2. Remove upper outside panel and open hinged door to
gain access to motor.

LOW CHARGE COOLING — Using appropriate cooling
charging chart (see Fig. 41 and 42), add or remove refrigerant 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 service valve using pressure gage. Connect temperature sensing
device to liquid line near the liquid line service valve and
insulate it so that outdoor ambient temperature does not affect reading. Indoor-air cfm must be within normal operating range of unit. Take outdoor ambient temperature and read
the suction pressure gage. Refer to appropriate chart to determine correct suction temperature. If intersection point on
chart is above the curve, add refrigerant. If intersection point
on chart is below curve, carefully recover some of the charge.
Recheck suction pressure as charge is adjusted.

Filter Drier — Replace whenever refrigerant system is
exposed to atmosphere.

Thermostatic Expansion Valve (TXV) — Each circuit has one. It is nonadjustable and is factory set to maintain 10 to 13° F superheat leaving the evaporator coil. Controls flow of liquid refrigerant to the evaporator coils.

Fig. 39 — Belt Tension Adjustment

Protective Devices
COMPRESSOR PROTECTION
Overcurrent — Each compressor has one manual reset, calibrated trip, magnetic circuit breaker. Do not bypass connections 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
only) has an internal protector to protect it against excessively high discharge gas temperatures.
Fig. 40 — Condenser-Fan Adjustment

44

Crankcase Heater — Each compressor has a crankcase heater
to prevent absorption of liquid refrigerant by oil in the crankcase when the compressor is idle. Since power for the crankcase heaters is drawn from the unit incoming power, main
unit power must be on for the heaters to be energized.

Relief Devices — All units have relief devices to protect against damage from excessive pressures (i.e., fire). These
devices are installed on the suction line, liquid line, and on
the compressor.

IMPORTANT: After a prolonged shutdown or service job, energize the crankcase heaters for 24 hours
before starting the compressors.

tected against overcurrent by a 3.2-amp circuit breaker (CB4).
Breaker can be reset. If it trips, determine cause of trouble
before resetting.

Control Circuit, 24-V — This control circuit is pro-

Control Circuit, 115-V — This control circuit is protected against overcurrent by a 5.0-amp circuit breaker (CB3).
Breaker can be reset. If it trips, determine cause of trouble
before resetting.

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 evaporatorfan motor is replaced with a different horsepower motor, resizing 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 activates, that refrigerant circuit will be automatically locked
out. To reset, manually move the thermostat setting.

Compressor Lockout Logic — If any of the safeties 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 control circuit breaker, or opening the thermostat.

Replacement Parts — A complete list of replacement
parts may be obtained from any Carrier distributor upon
request.

FREEZE PROTECTION THERMOSTAT (FPT) — An FPT
is located on the evaporator coil for each circuit. It detects
frost build-up and turns off the compressor, allowing the coil
to clear. Once the frost has melted, the compressor can be
reenergized.

Fig. 41 — Cooling Charging Chart,
Sizes 024-034

Fig. 42 — Cooling Charging Chart,
Sizes 038-048
45

TROUBLESHOOTING
Typical refrigerant circuiting diagrams are shown in Fig. 43-45.

LEGEND
FPS — Freeze Protection Switch
HPS — High-Pressure Switch
LPS — Low-Pressure Switch

Fig. 43 — Typical Refrigerant Circuiting
(50EJ,EK,EW,EY024-034)

46

LEGEND
FPS — Freeze Protection Switch
HPS — High-Pressure Switch
LPS — Low-Pressure Switch

Fig. 44 — Typical Refrigerant Circuiting
(50EJ,EK,EW,EY038,044)

47

LEGEND
FPS — Freeze Protection Switch
HPS — High-Pressure Switch
LPS — Low-Pressure Switch

Fig. 45 — Typical Refrigerant Circuiting
(50EJ,EW048)

48

to Table 20 below for a description of alarms. The yellow
LED blinks during transmission with the CCN (Carrier Comfort Network). The green LED blinks during transmission
with the expansion board.

Diagnostic LEDs (Light-Emitting Diodes) — 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

Table 20 — Control Board LED Alarms
LED
BLINKS
1

ERROR
CODE

DESCRIPTION
Normal Operation

2

HF-13

Compressor 1 Safety

3

HF-14

Compressor 2 Safety

4

HF-15

Thermostat Failure

5

HF-05

SAT Thermistor Failure

6

HF-06

OAT Thermistor Failure

7

HF-03

Space Temp. Sen. Failure

8

HF-12

RAT Thermistor Failure

9

SE-05

Loss of Communications
with Expansion board

10

HF-16

Control Board Failure

11

HF-17

Expansion Board Failure

TROUBLESHOOTING
COMMENTS
The expansion board and control board flash the red LED in onesecond intervals when the board is operating properly.
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 minutes, compressor no. 1 will be
locked out until the control board has been manually reset.
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 minutes, compressor no. 2 will be
locked out until the control board has been manually reset.
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.
The supply-air temperature (SAT) sensor has failed. First check for
wiring errors, then replace sensor.
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.
Communications between the expansion board and the control
board have been interrupted. Ensure that an expansion board
is installed and wired using 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.
Generated when hardware has failed on control board. Replace
the control board.
Generated when hardware has failed on the expansion board.
Replace the expansion board.

LEGEND
DIP — Dual In-Line Package
LED — Light-Emitting Diode
VAV — Variable Air Volume

49

Tables 21-23 show the input and output channel designations.
Table 21 — I/O Channel Designations
Base Module — CV
TERMINAL
NO.
T1-2
T3-4
T5-6
T7-8
T9-10
T11-12
T13-14
T15-16
T17-25
T18-25
T19-25
T20-25
T21-25
T22-25
T23-25
T24-25
T26-27
T28-29
T30-29
T31-32
T33-32
T34-35
T36-35
T37-38
T39-38
K1
K2
K3

Table 22 — I/O Channel Designations
Base Module — VAV
TERMINAL
NO.
T1-2
T3-4
T5-6
T7-8
T9-10
T11-12
T13-14
T15-16
T17-25
T18-25
T19-25
T20-25
T21-25
T22-25
T23-25
T24-25
T26-27
T28-29
T30-29
T31-32
T33-32
T34-35
T36-35
T37-38
T39-38
K1
K2
K3

ASSIGNMENT
SPT (CCN) — 10KV Thermistor
STO (CCN) — 10KV Thermistor
OAT — 5KV Thermistor
SAT — 5KV Thermistor
—
SAT Reset — AI (2-10 vdc)
—
—
Y1 or Remote Start/Stop — DI (24 vac)
Y2 — DI (24 vac)
W1 — DI (24 vac)
W2 — DI (24 vac)
G — DI (24 vac)
Compressor 1 Safety — DI (24 vac)
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 2 Relay — DO (24 vac)
CV Power Exhaust 1/Modulating Pwr Exht — DO
(115 vac)
CV Power Exhaust 2 — DO (115 vac)
Condenser Fan — DO (115 vac)
OFC2 — DO (115 vac)
—
—
Indoor Fan Relay — DO (HV)
Compr. 1 — DO (HV)
Compr. 2 — DO (HV)

LEGEND
(Tables 21 and 22)
AI
AO
CCN
CV
DI
DO
HV
KV
OAT
OFC
RAT
SAT
SPT
STO
T
VAV

—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—

Analog Input
Analog Output
Carrier Comfort Network
Constant Volume
Direct Input
Direct Output
High Voltage
Kilo-Ohms
Outdoor-Air Temperature
Outdoor Fan Contactor
Return-Air Temperature
Supply-Air Temperature
Space Temperature
Space Temperature Offset
Terminal
Variable Air Volume

50

ASSIGNMENT
SPT (CCN) — 10KV Thermistor
RAT — 5KV Thermistor
OAT — 5KV Thermistor
SAT — 5KV Thermistor
—
SAT Reset — AI (2-10 vdc)
—
—
Remote Start/Stop — DI (24 vac)
—
—
—
—
Compressor 1 Safety — DI (24 vac)
Compressor 2 Safety — DI (24 vac)
Outside Air Enthalpy — DI (24 vac)
Economizer Pos. — AO (4-20 mA)
Heat 1 Relay — DO (115 vac)
Heat Interlock Relay — DO (115 vac)
Modulated Power Exhaust — DO (115 vac)
—
Condenser Fan — DO (115 vac)
OFC2 — DO (115 vac)
Unloader 1 — DO (115 vac)
Unloader 2 — DO (115 vac)
Indoor Fan Relay — DO (HV)
Compr. 1 — DO (HV)
Compr. 2 — DO (HV)

Table 23 — I/O Channel Designations Expansion
Module — CV and VAV
TERMINAL
NO.
T1-2
T3-4
T5-6
T7-8
T9-10
T11-12
T13-14
T15-16
T17-25
T18-25
T19-25
T20-25
T21-25
T22-25
T23-25
T24-25
T26-27
T28-29
T30-29
T31-32
T33-32
T34-35
T36-35
T37-38
T39-38
K1
K2
K3
AI
DI
DO
IAQ
T

—
—
—
—
—

ASSIGNMENT
—
—
—
—
—
IAQ Indoor — AI (2-10 vdc)
IAQ Outdoor — AI (2-10 vdc)
—
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)
Fire — Evacuation — DI (24 vac)
Fire — Smoke Purge — DI (24 vac)
—
—
Alarm Light Indicator — DO (24 vac)
Power Exhaust Fire #1 — DO (115 vac)
Power Exhaust Fire #2 — DO (115 vac)
Power Exhaust Fire #3 — DO (115 vac)
Power Exhaust Fire #4 — DO (115 vac)
—
—
—
—
—

LEGEND
Analog Input
Direct Input
Direct Output
Indoor Air Quality
Terminal

51

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 1996 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. 535-006
Printed in U.S.A.
Form 50E-3SI
Pg 54
8-96
Replaces: 50E-1SI
Tab 1b

START-UP CHECKLIST
MODEL NO.:

SERIAL NO.:

SOFTWARE VERSION (SEE FIG. 15)

TECHNICIAN:

DATE:

PRE-START-UP:
M VERIFY THAT DIP SWITCH SETTINGS ARE CORRECT
M VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT
M REMOVE ALL SHIPPING HOLDDOWN BOLTS AND BRACKETS PER INSTRUCTIONS
M VERIFY INSTALLATION OF ECONOMIZER HOOD
M VERIFY INSTALLATION OF ALL OPTIONS AND ACCESSORIES
M VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS
M VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT
M CHECK THAT INDOOR-AIR FILTER IS CLEAN AND IN PLACE
M VERIFY THAT UNIT IS LEVEL WITHIN TOLERANCES
M CHECK FAN WHEELS AND PROPELLERS FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SET SCREW
IS TIGHT
M VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED
M VERIFY THAT SUCTION, DISCHARGE, AND LIQUID LINE SERVICE VALVES ON EACH CIRCUIT ARE OPEN

START-UP
ELECTRICAL
SUPPLY VOLTAGE

L1-L2

L2-L3

L3-L1

COMPRESSOR AMPS — COMPRESSOR NO. 1

L1

L2

L3

— COMPRESSOR NO. 2

L1

L2

L3

SUPPLY FAN AMPS (CV)

EXHAUST FAN AMPS

(VAV)

*

*VAV fan supply amps reading must be taken with a true RMS meter for accurate readings.
ELECTRIC HEAT AMPS (IF SO EQUIPPED)

L1

L2

TEMPERATURES
OUTDOOR-AIR TEMPERATURE

F

DB (Dry-Bulb)

RETURN-AIR TEMPERATURE

F

DB

COOLING SUPPLY AIR

F

L3

F

ELECTRIC HEAT SUPPLY AIR (IF SO EQUIPPED)

WB (Wet-Bulb)

F

PRESSURES
REFRIGERANT SUCTION

CIRCUIT NO. 1

PSIG

CIRCUIT NO. 2

PSIG

REFRIGERANT DISCHARGE

CIRCUIT NO. 1

PSIG

CIRCUIT NO. 2

PSIG

M VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS ON PAGE 45

CL-1

M ECONOMIZER MINIMUM VENT AND CHANGEOVER SETTINGS TO JOB REQUIREMENTS
M ENSURE DRIVES OPERATE WITHIN LIMITS OF FAN PERFORMANCE TABLES
HIGH-PRESSURE SWITCH SETTING

PSIG

LOW-PRESSURE SWITCH SETTING

PSIG

MOTOR PULLEY PART NUMBER
FAN PULLEY PART NUMBER
BELT PART NUMBER
BELT SIZE

in.

FILTER QUANTITY
FILTER SIZES

in.

CUT ALONG DOTTED LINE

ADDITIONAL NOTES:

CUT ALONG DOTTED LINE

GENERAL

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

START-UP CHECKLIST (cont)

Copyright 1996 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. 535-006
Printed in U.S.A.
Form 50E-3SI
Pg CL-2
8-96
Replaces: 50E-1SI
Tab 1b



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