Carrier Single Package Rooftop Units Electric Cooling Gas Heating 48Ej Users Manual

48EJ to the manual b9a43d94-fd73-49a9-aa7f-83f77933caab

2015-01-24

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Page Count: 64

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 ..................2

• POSITIONING

• ROOF MOUNT

Step 3 — Field Fabricate Ductwork ............2

Step 4 — Install Flue Hood ..................12

Step5—TrapCondensate Drain ............13

Step 6 — Install Gas Piping ..................13

Step 7 — Controls Options ..................13

• CONSTANT VOLUME APPLICATIONS

• VARIABLE AIR VOLUME (VAV) APPLICATIONS

Step 8 — Make Electrical Connections .......16

• POWER WIRING

• FIELD POWER SUPPLY

• FIELD CONTROL WIRING

Step 9 — Make Outdoor-Air Inlet

Adjustments ...............................24

• ECONOMIZER

• ECONOMIZER SETTINGS

Step 10 — Position Power Exhaust/Barometric

Relief Hood ...............................29

Step 11 — Install All Accessories ............30

START-UP ................................31-44

SERVICE ..................................44-55

TROUBLESHOOTING ......................56-61

START-UP CHECKLIST ................CL-1,CL-2

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment

can be hazardous due to system pressure and electrical com-

ponents. Only trained and qualiﬁed service personnel should

install, repair, or service air-conditioning equipment.

Untrained personnel can perform the basic maintenance

functions of cleaning coils and ﬁlters and replacing ﬁlters.

All other operations should be performed by trained service

personnel. When working on air-conditioning equipment, ob-

serve precautions in the literature, tags and labels attached

to the unit, and other safety precautions that may apply.

Follow all safety codes. Wear safety glasses and work gloves.

Use quenching cloth for unbrazing operations. Have ﬁre ex-

tinguishers available for all brazing operations.

Before performing service or maintenance operations on

unit, turn off main power switch to unit. Electrical shock

could cause personal injury.

1. Improper installation, adjustment, alteration, serv-

ice, or maintenance can cause property damage, per-

sonal injury, or loss of life. Refer to the User’s

Information Manual provided with this unit for more

details.

2. Do not store or use gasoline or other ﬂammable va-

pors and liquids in the vicinity of this or any other

appliance.

What to do if you smell gas:

1. DO NOT try to light any appliance.

2. DO NOT touch any electrical switch, or use any phone

in your building.

3. IMMEDIATELY call your gas supplier from a neigh-

bor’s phone. Follow the gas supplier’s instructions.

4. If you cannot reach your gas supplier, call the ﬁre

department.

Disconnect gas piping from unit when pressure testing

at pressure greater than 0.5 psig. Pressures greater than

0.5 psig will cause gas valve damage resulting in haz-

ardous condition. If gas valve is subjected to pressure

greater than 0.5 psig, it must be replaced before use. When

pressure testing ﬁeld-supplied gas piping at pressures of

0.5 psig or less, a unit connected to such piping must be

isolated by closing the manual gas valve(s).

INSTALLATION

Step 1 — Provide Unit Support

1. All panels must be in place when rigging.

2. Unit is not designed for handling by fork truck.

ROOF CURB — Assemble or install accessory roof curb in

accordance with instructions shipped with this accessory. See

Fig. 1 and 2. Install insulation, cant strips, rooﬁng, and counter

ﬂashing as shown. Ductwork can be installed to roof curb

before unit is set in place. Curb should be level. This is nec-

essary to permit unit drain to function properly. Unit level-

ing tolerance is shown in Fig. 1 and 2. Refer to Accessory

Roof Curb Installation Instructions for additional informa-

tion as required. When accessory roof curb is used, unit may

be installed on class A, B, or C roof covering material.

IMPORTANT: The gasketing of the unit to the roof

curb is critical for a watertight seal. Install gasket with

the roof curb as shown in Fig. 1 and 2. Improperly

applied gasket can also result in air leaks and poor unit

performance.

48EJ,EK,EW,EY024-048

Single Package Rooftop Units

Electric Cooling/Gas Heating

Manufacturer reserves the right to discontinue, or change at any time, speciﬁcations or designs without notice and without incurring obligations.

Book 1

Tab 1a

PC 111 Catalog No. 564-962 Printed in U.S.A. Form 48E-5SI Pg 1 8-97 Replaces: 48E-3SI

ALTERNATE UNIT SUPPORT — When the preferred curb

or slab mount cannot be used, support unit with sleepers on

perimeter, using unit curb support area. If sleepers cannot be

used, support long sides of unit (refer to Fig. 3-6) with a

minimum number of 4-in. x 4-in. pads spaced as follows:

48EJ,EK,EW,EY024-034 units require 3 pads on each side;

48EJ,EK,EW,EY038-048 units require 4 pads on each side.

Unit may sag if supported by corners only.

Step 2 — Rig and Place Unit — Inspect unit for trans-

portation damage. File any claim with transportation agency.

Do not drop unit; keep upright. Use spreader bars over

unit to prevent sling or cable damage. Level by using unit

frame as a reference; leveling tolerance is shown in Fig. 1

and 2. See Fig. 7 for additional information. Unit operating

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 old unit. Attach existing ductwork to roof

curb instead of unit.

Four lifting lugs are provided on the unit base rails as shown

in Fig. 7. Refer to rigging instructions on unit.

POSITIONING — Maintain clearance, per Fig. 3-6, around

and above unit to provide minimum distance from combus-

tible materials, proper airﬂow, and service access.

Do not install unit in an indoor location. Do not locate

unit air inlets near exhaust vents or other sources of con-

taminated air. For proper unit operation, adequate combus-

tion and ventilation air must be provided in accordance with

Section 5.3 (Air for Combustion and Ventilation) of the

National Fuel Gas Code, ANSI Z223.1 (American National

Standards Institute).

Although unit is weatherproof, guard against water from

higher level runoff and overhangs.

Locate mechanical draft system ﬂue assembly at least

4 ft from any opening through which combustion products

could enter the building, and at least 4 ft from any adjacent

building. When unit is located adjacent to public walkways,

ﬂue assembly must be at least 7 ft above grade.

ROOF MOUNT — Check building codes for weight distri-

bution requirements. Unit weight is shown in Table 1.

Step 3 — Field Fabricate Ductwork

48EJ,EK UNITS — Field-fabricated ductwork should be at-

tached to the roof curb. Supply and return duct dimensions

are shown in Fig. 3 and 4. Air distribution is shown in

Fig. 8.

To attach ductwork to roof curb, insert duct approxi-

mately 10 to 11 in. up into roof curb. Connect ductwork to

14-gage roof curb material with sheet metal screws driven

from inside the duct.

Secure all ducts to the building structure, using ﬂexible

duct connectors between roof curb and ducts as required. Ducts

passing through an unoccupied space must be insulated and

covered with a vapor barrier. Outlet grilles must not lie

directly below unit discharge. The return duct must have a

90-degree elbow before opening into the building space if

the unit is equipped with power exhaust.

For vertical supply and return units, tools or parts could

drop into ductwork and cause an injury. Install 90 de-

gree elbow turns in the supply and return ductwork be-

tween the unit and the conditioned space. If a 90 degree

elbow cannot be installed, then grilles of sufficient strength

and density should be installed to prevent objects from

falling into the conditioned space.

48EW,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 struc-

ture. See Fig. 9. Use ﬂexible duct connectors between unit

and ducts as required. Insulate and weatherproof all external

ductwork, joints, and building openings with counter ﬂash-

ing and mastic in accordance with applicable codes.

Ducts passing through an unconditioned space must be

insulated and covered with a vapor barrier.

Install accesssory barometric relief or power exhaust in

the ﬁeld-fabricated return ductwork. Refer to Position Power

Exhaust/Barometric Relief Damper Hood section on

page 26 for more information.

Instructions continued on page 12.

NOTES:

1. All roof curb parts are to be 16 ga galvanized steel.

2. Dimensions are in inches.

3. To prevent standing water in the drain pan of the indoor

section and the heat exchangers, unit can only be pitched

as shown.

UNIT LEVELING TOLERANCES DIMENSIONS*

(Degrees and Inches)

Deg. in. Deg. in.

1.0 2.9 .50 .75

*From edge of unit to horizontal.

Fig. 1 — Roof Curb (Sizes 024-034)

NOTES:

1. All roof curb parts are to be 16 ga galvanized steel.

2. Dimensions are in inches.

3. To prevent standing water in the drain pan of the indoor

section and the heat exchangers, unit can only be pitched

as shown.

UNIT LEVELING TOLERANCES DIMENSIONS*

(Degrees and Inches)

Deg. in. Deg. in.

1.0 2.9 .50 .75

*From edge of unit to horizontal.

Fig. 2 — Roof Curb (Sizes 038-048)

VFD — Variable Frequency Drive

NOTES:

1. Weights include economizer (STD).

2. Center of gravity.

3. Do not locate adjacent units with ﬂue dis-

charge facing economizer inlet. Minimum clear-

ances to be:

Adjacent Units: 158-09

Top of Units: No overhang

Condenser Coil: 48-09

Economizer Side: 68-09

Gas Heat Side: 48-09

Filter Access Side: 108-09(For Removal of

Evaporator Coil)

4. For smaller service and operational clear-

ances, contact Carrier Application Engineer-

ing department.

5. Bottom ducts designed to be attached to ac-

cessory roof curb. If unit is mounted on dun-

nage, it is recommended the ducts be

supported by cross braces as done on ac-

cessory roof curb.

6. Dimensions are in inches.

UNIT

SIZE

OPERATING

WEIGHT A B CORNER WEIGHT (lb)

lb ft-in. ft-in. 1 2 3 4

48EJ,EKD024 4176 6- 0

⁄

3-6

⁄

879 954 1220 1124

48EJE024 4256 6- 1

⁄

3-6

⁄

917 973 1218 1148

48EJ,EKD028 4262 5- 9

⁄

3-8 899 899 1232 1232

48EJE028 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

48EJ,EKD030 4262 5- 9

⁄

3-8 899 899 1232 1232

48EJE030 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

48EJ,EKD034 4262 5- 9

⁄

3-8 899 899 1232 1232

48EJE034 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

Fig. 3 — Base Unit Dimensions, 48EJ,EK024-034

VFD — Variable Frequency Drive

NOTES:

1. Weights include economizer (STD).

2. Center of gravity.

3. Do not locate adjacent units with ﬂue discharge facing econo-

mizer inlet. Minimum clearances to be:

Adjacent Units: 158-09

Top of Units: No overhang

Condenser Coil: 48-09

Economizer Side: 68-09

Gas Heat Side: 48-09

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.

UNIT

SIZE

OPERATING

WEIGHT A B CORNER WEIGHT (lb)

lb ft-in. ft-in. 1 2 3 4

48EJ,EKD038 4442 7- 8

⁄

3-10

⁄

1021 894 1180 1347

48EJE038 4602 7-10

⁄

3-11

⁄

1080 934 1200 1388

48EJ,EKD044 4668 7- 5

⁄

3-10

⁄

1033 906 1275 1455

48EJE044 4828 7- 6

⁄

3-11

⁄

1094 945 1293 1496

48EJ,EKD048 4955 7- 3

⁄

3-10

⁄

1068 953 1384 1550

48EJE048 5115 7- 5

⁄

3-10

⁄

1129 994 1401 1592

Fig. 4 — Base Unit Dimensions, 48EJ,EK038-048

VFD — Variable Frequency Drive

NOTES:

1. Weights include economizer (STD).

2. Center of gravity.

3. Do not locate adjacent units with ﬂue 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

Gas Heat Side: 48-09

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.

6. For side-supply/return applications, a single return and supply ductwork

connection is recommended for covering both return and both supply

openings.

UNIT

SIZE

OPERATING

WEIGHT A B CORNER WEIGHT (lb)

lb ft-in. ft-in. 1 2 3 4

48EW,EYD024 4176 6- 0

⁄

3-6

⁄

879 954 1220 1124

48EWE024 4256 6- 1

⁄

3-6

⁄

917 973 1218 1148

48EW,EYD028 4262 5- 9

⁄

3-8 899 899 1232 1232

48EWE028 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

48EW,EYD030 4262 5- 9

⁄

3-8 899 899 1232 1232

48EWE030 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

48EW,EYD034 4262 5- 9

⁄

3-8 899 899 1232 1232

48EWE034 4342 5-10

⁄

3-8

⁄

929 916 1240 1257

Fig. 5 — Base Unit Dimensions, 48EW,EY024-034

VFD — Variable Frequency Drive

NOTES:

1. Weights include economizer (STD).

2. Center of gravity.

3. Do not locate adjacent units with ﬂue 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

Gas Heat Side: 48-09

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.

6. For side-supply/return applications, a single return and supply duct-

work connection is recommended for covering both return and both

supply openings.

UNIT

SIZE

OPERATING

WEIGHT A B CORNER WEIGHT (lb)

lb ft-in. ft-in. 1 2 3 4

48EW,EYD038 4442 7- 8

⁄

3-10

⁄

1021 894 1180 1347

48EWE038 4602 7-10

⁄

3-11

⁄

1080 934 1200 1388

48EW,EYD044 4668 7- 5

⁄

3-10

⁄

1033 906 1275 1455

48EWE044 4828 7- 6

⁄

3-11

⁄

1094 945 1293 1496

48EW,EYD048 4955 7- 3

⁄

3-10

⁄

1068 953 1384 1550

48EWE048 5115 7- 5

⁄

3-10

⁄

1129 994 1401 1592

Fig. 6 — Base Unit Dimensions, 48EW,EY038-048

UNIT WEIGHT A B C

lb kg in. mm in. mm in. mm

48EJ,EK,EW,EYD024 4176 1894

87.68 2227

72.4 1839 42.4 1072

48EJ,EWE024 4256 1930 73.3 1862 42.7 1085

48EJ,EK,EW,EYD028

4262 1933 69.6 1768 44.0 111848EJ,EK,EW,EYD030

48EJ,EK,EW,EYD034

48EJ,EWE028

4342 1969 70.1 1781 44.3 112548EJ,EWE030

48EJ,EWE034

48EJ,EK,EW,EYD038 4442 2015

150 3810

92.7 2355 46.9 1191

48EJ,EWE038 4602 2087 94.1 2390 47.2 1199

48EJ,EK,EW,EYD044 4668 2117 89.3 2268 46.9 1191

48EJ,EWE044 4828 2190 90.8 2306 47.2 1199

48EJ,EK,EW,EYD048 4955 2248 87.7 2228 46.5 1181

48EJ,EWE048 5115 2320 89.2 2266 46.8 1189

NOTICE TO RIGGERS:

ALL PANELS MUST BE IN PLACE

WHEN RIGGING.

NOTE: Rig with four cables and spread with two

92 in. (2337 mm) spreader bars. Maintain a dis-

tance of 74 in. (1880 mm) from top of unit to

eyehook.

NOTE:

Add 32 lb (14.5 kg) for domestic crating.

Add 312 lb (142 kg) for export crating (024-034 units).

Add 346 lb (157 kg) for export crating (038-048 units).

Add 250 lb (113 kg) for power exhaust.

Add 220 lb (100 kg) for copper condenser coil (024-034 units).

Add 285 lb (129 kg) for copper condenser coil (038,044 units).

Add 380 lb (172 kg) for copper condenser coil (048 unit).

Fig. 7 — Rigging Label

Table 1 — Physical Data

UNIT 48EJ,EK,EW,EY 024D/E 028D/E 030D/E 034D/E

NOMINAL CAPACITY (tons) 20 25 27 30

OPERATING WEIGHT (lb)*

Unit

Al/Al† (Lo Heat/Hi Heat) 4176/4256 4262/4342 4262/4342 4262/4342

Al/Cu† (Lo Heat/Hi Heat) 4396/4476 4482/4562 4482/4562 4482/4562

Roof Curb (14-in. curb) 365 365 365 365

COMPRESSOR

Type Ckt 1 06D328 06D328 06D537 06D537

Ckt 2 06D818 06D328 06D328 06D537

Number of Refrigerant Circuits 22 2 2

Oil (oz) (Ckt 1, Ckt 2) 115, 88 115 ea. 115 ea. 115 ea.

REFRIGERANT TYPE R-22

Operating Charge (lb-oz)

Circuit 1** 25-0 25-0 25-0 25-0

Circuit 2 31-0 25-0 25-0 25-0

CONDENSER COIL Cross-Hatched

⁄

9Copper Tubes, Aluminum Lanced, Aluminum Pre-Coated, or Copper Plate Fins

Quantity 11 1 1

Rows...Fins/in. 4...15 4...15 4...15 4...15

Total Face Area (sq ft) 33.3 33.3 33.3 33.3

CONDENSER FAN Propeller Type

Nominal Cfm 13,420 13,420 13,420 13,420

Quantity...Diameter (in.) 2...30 2...30 2...30 2...30

Motor Hp (1075 Rpm) 11 1 1

EVAPORATOR COIL Cross-Hatched

⁄

9Copper Tubes, Aluminum Plate Fins, Intertwined Circuits

Rows...Fins/in. 4...15 4...15 4...15 4...15

Total Face Area (sq ft) 31.7 31.7 31.7 31.7

EVAPORATOR FAN Centrifugal Type

Quantity...Size (in.) 2...20x15 2...20x15 2...20x15 2...20x15

Type Drive Belt Belt Belt Belt

Nominal Cfm 8,000 10,000 11,000 12,000

Motor Hp 5 10†† 15 7.5 10†† 15 10 15†† 20 10 15†† 20

Motor Frame Size (Standard) S184T S215T D254T S213T S215T D254T S215T D254T S256T S215T D254T S256T

(High Efficiency) S184T S215T S254T S213T S215T S254T S215T S254T S256T S215T S254T S256T

Motor Bearing Type Ball Ball Ball Ball

Maximum Allowable Rpm 1200 1200 1200 1200

Motor Pulley Pitch Diameter 4.8 4.4 5.7 5.4 6.1 5.5 4.4 4.9 5.9 4.4 5.7 5.9

Nominal Motor Shaft Diameter (in.) 1

⁄

Fan Pulley Pitch Diameter (in.) 12.4 8.6 9.1 12.4 11.1 8.7 9.4 8.1 8.7 9.0 9.1 8.7

Nominal Fan Shaft Diameter (in.) 1

⁄

Belt, Quantity...Type

Belt, Length (in.) 1...BX59

62 2...BX51

54 2...5VX530

53 1...BX59

62 1...5VX590

59 2...5VX530

53 2...BX52

55 2...5VX500

50 2...5VX530

53 2...BX51

54 2...5VX530

53 2...5VX530

Pulley Center Line Distance (in.) 16.0-18.7 15.6-18.4 15.0-17.9 15.6-18.4 15.0-17.9 15.6-18.4 15.0-17.9 15.6-18.4 15.0-17.9

Factory Speed Setting (rpm) 717 924 1096 773 962 1106 848 1059 1187 884 1096 1187

FURNACE SECTION

Rollout Switch Cutout Temp (F)|225 225 225 225

Burner Oriﬁce Diameter

(in. ...drill size)

Natural Gas Std .111...34 .111...34 .111...34 .111...34

Liquid Propane Alt .089...43 .089...43 .089...43 .089...43

Thermostat Heat Anticipator

Setting (amps)

Stage 1 0.1 0.1 0.1 0.1

Stage 2 0.1 0.1 0.1 0.1

Gas Input (Btuh) Stage 1 Low 262,500 262,500 262,500 262,500

High 394,000 394,000 394,000 394,000

Stage 2 Low 350,000 350,000 350,000 350,000

High 525,000 525,000 525,000 525,000

Efficiency (Steady State) (%) 82 82 82 82

Temperature Rise Range 15-45/35-65 15-45/35-65 15-45/35-65 15-45/35-65

Manifold Pressure (in. wg)

Natural Gas Std 3.5 3.5 3.5 3.5

Liquid Propane Alt 3.5 3.5 3.5 3.5

Gas Valve Quantity 22 2 2

Field Gas Connection Size

(in.-FPT) 1.5 1.5 1.5 1.5

HIGH-PRESSURE SWITCH (psig)

Cutout 426 426 426 426

Reset (Auto.) 320 320 320 320

LOW-PRESSURE SWITCH (psig)

Cutout 77 7 7

Reset (Auto.) 22 22 22 22

OUTDOOR-AIR FILTERS 8...16 × 25

Quantity...Size (in.) 4...20 × 25

RETURN-AIR FILTERS

Quantity...Size (in.) 10...20x24x2 10...20x24x2 10...20x24x2 10...20x24x2

POWER EXHAUST Direct Drive, 3-Speed, Single-Phase Motor (Factory-Wired for High Speed) and Forward-Curved Fan

Motor, Quantity...Hp 4...1 4...1 4...1 4...1

Fan, Diameter... Width (in.) 11...10 11...10 11...10 11...10

LEGEND

Al — Aluminum

Cu — Copper

*Weight of unit does not include variable frequency drive (VFD) barometric relief, or power

exhaust. If a VFD is installed, add the VFD weight in the table at right.

†Evaporator coil ﬁn material/condenser coil ﬁn material.

**Sizes 024-034: Circuit 1 uses the lower portion of condenser coil, Circuit 2 uses the upper

portion. Sizes 038-048: Circuit 1 uses the left condenser coil, Circuit 2 the right. All units

have intertwined evaporator coils.

††Motor and drive shown will deliver approximately 2.5 in. wg net external static. See

Table 2 for more information.

\Rollout switch is manual reset.

NOTE: High heat is for 48EJ,EW only.

VFD

(Hp) VFD WEIGHTS (lb)

208/230 v 460 v 575 v

520 22 60

7.5 51 37 64

10 51 61 64

15 61 63 109

20 63 111 109

25 105 112 174

30 172 118 180

Table 1 — Physical Data (cont)

UNIT 48EJ,EK,EW,EY 038D/E 044D/E 048D/E

NOMINAL CAPACITY (tons) 35 40 45

OPERATING WEIGHT (lb)*

Unit

Al/Al† (Lo Heat/Hi Heat) 4442/4602 4668/4828 4955/5115

Al/Cu† (Lo Heat/Hi Heat) 4727/4887 4953/5113 5335/5495

Roof Curb (14-in. curb) 410 410 410

COMPRESSOR

Type Ckt 1 06D537 06EA250 06EA265

Ckt 2 06D537 06EA250 06EA250

Number of Refrigerant Circuits 222

Oil (oz) (Ckt 1, Ckt 2) 115 ea. 224 ea. 304, 224

REFRIGERANT TYPE R-22

Operating Charge (lb-oz)

Circuit 1** 34-0 35-0 41-0

Circuit 2 34-0 35-0 41-0

CONDENSER COIL Cross-Hatched

⁄

9Copper Tubes, Aluminum Lanced, Aluminum Pre-Coated, or Copper Plate Fins

Quantity 2211

Rows...Fins/in. 3...15 3...15 4...15 3...15

Total Face Area (sq ft) 58.3 58.3 66.7

CONDENSER FAN Propeller Type

Nominal Cfm 27,064 27,064 27,064

Quantity...Diameter (in.) 4...30 4...30 4...30

Motor Hp (1075 Rpm) 111

EVAPORATOR COIL Cross-Hatched

⁄

9Copper Tubes, Aluminum Plate Fins, Intertwined Circuits

Rows...Fins/in. 3...15 3...15 4...15

Total Face Area (sq ft) 34.7 34.7 34.7

EVAPORATOR FAN Centrifugal Type

Quantity...Size (in.) 2...20x15 2...20x15 2...20x15

Type Drive Belt Belt Belt

Nominal Cfm 14,000 16,000 18,000

Motor Hp 10 15†† 20 15 20†† 25 20 25†† 30

Motor Frame Size (Standard) S215T D254T S256T D254T S256T S284T S256T S284T S286T

(High Efficiency) S215T S254T S256T S254T S256T S284T S256T S284T S286T

Motor Bearing Type Ball Ball Ball

Maximum Allowable Rpm 1200 1200 1200

Motor Pulley Pitch Diameter 6.1 5.3 5.7 5.3 5.7 7.5 6.3 5.9 7.5

Nominal Motor Shaft Diameter (in.) 1

⁄

Fan Pulley Pitch Diameter (in.) 13.7 9.5 9.5 9.5 9.5 11.1 11.1 12.5 11.1

Nominal Fan Shaft Diameter (in.) 1

⁄

Belt, Quantity...Type

Belt, Length (in.) 1...5VX650

65 2...5VX530

53 2...5VX550

55 2...5VX530

53 2...5VX550

55 2...5VX590

59 2...5VX570

57 2...5VX630

63 2...5VX610

Pulley Center Line Distance (in.) 15.6-18.4 15.0-17.9 15.0-17.9 14.6-17.6 15.0-17.9 14.6-17.6

Factory Speed Setting (rpm) 779 976 1050 976 1050 1182 993 1134 1182

FURNACE SECTION

Rollout Switch Cutout Temp (F)|225 225 225

Burner Oriﬁce Diameter

(in. ...drill size)

Natural Gas Std .120...31 .120...31 .120...31

Liquid Propane Alt .096...41 .096...41 .096...41

Thermostat Heat Anticipator

Setting (amps)

Stage 1 0.1 0.1 0.1

Stage 2 0.1 0.1 0.1

Gas Input (Btuh) Stage 1 Low 300,000 300,000 300,000

High 600,000 600,000 600,000

Stage 2 Low 400,000 400,000 400,000

High 800,000 800,000 800,000

Efficiency (Steady State) (%) 82 82 82

Temperature Rise Range 10-40/30-60 10-40/30-60 10-40/30-60

Manifold Pressure (in. wg)

Natural Gas Std 3.5 3.5 3.5

Liquid Propane Alt 3.5 3.5 3.5

Gas Valve Quantity 222

Field Gas Connection Size (in.-FPT) 1.5 1.5 1.5

HIGH-PRESSURE SWITCH (psig)

Cutout 426 426 426

Reset (Auto.) 320 320 320

LOW-PRESSURE SWITCH (psig)

Cutout 777

Reset (Auto.) 22 22 22

OUTDOOR-AIR FILTERS 8...16 × 25

Quantity...Size (in.) 4...20 × 25

RETURN-AIR FILTERS

Quantity...Size (in.) 10...20x24x2 10...20x24x2 10...20x24x2

POWER EXHAUST Direct Drive, 3-Speed, Single-Phase motor (Factory-Wired for High Speed) and Forward Curved Fan

Motor, Quantity...Hp 4...1 4...1 4...1

Fan, Diameter... Width (in.) 11...10 11...10 11...10

LEGEND

Al — Aluminum

Cu — Copper

*Weight of unit does not include variable frequency drive (VFD) barometric relief, or power

exhaust. If a VFD is installed, add the VFD weight in the table at right.

†Evaporator coil ﬁn material/condenser coil ﬁn material.

**Sizes 024-034: Circuit 1 uses the lower portion of condenser coil, Circuit 2 uses the upper

portion. Sizes 038-048: Circuit 1 uses the left condenser coil, Circuit 2 the right. All units

have intertwined evaporator coils.

††Motor and drive shown will deliver approximately 2.5 in. wg net external static. See

Table 2 for more information.

\Rollout switch is manual reset.

NOTE: High heat is for 48EJ,EW only.

VFD

(Hp) VFD WEIGHTS (lb)

208/230 v 460 v 575 v

520 22 60

7.5 51 37 64

10 51 61 64

15 61 63 109

20 63 111 109

25 105 112 174

30 172 118 180

Table 2 — Evaporator Fan Motor Data (Units with Starting Serial Numbers 4197 and Later)

UNIT

SIZE

48E

MOTOR

SHAFT

DIA.

(in.)

FAN

SHAFT

SPEED

(rpm)

MOTOR

SHEAVE

MOTOR

SHEAVE

PITCH

DIAMETER

(in.)

BUSHING

DIAMETER

(in.)

FAN

SHEAVE

FAN

SHEAVE

PITCH

DIAMETER

(in.)

BUSHING

DIAMETER

(in.)

BELT

(QUANTITY)

OUTSIDE

BELT

LENGTH

BELT

TENSION

(Lb at

.24 in.)

024 5 1.12 717 BK55 4.8 None-1.125 1B5V124 12.4 B-1.9375 BX59 62 5.10

10 1.38 924 2BK50 4.4 None-1.375 2B5V86 8.6 B-1.9375 (2) BX51 54 5.21

15 1.62 1096 2B5V56 5.7 B-1.625 2B5V90 9.1 B-1.9375 (2) 5VX530 53 6.00

028 7.5 1.38 773 BK60H 5.4 H-1.375 1B5V124 12.4 B-1.9375 BX59 62 6.48

10 1.38 962 1B5V60 6.1 H-1.375 1B5V110 11.1 B-1.9375 5VX590 59 7.37

15 1.62 1106 2B5V54 5.5 B-1.625 2B5V86 8.7 B-1.9375 (2) 5VX530 53 6.12

030 10 1.38 848 2BK50 4.4 None-1.375 2B5V94 9.4 B-1.9375 (2) BX52 55 5.27

15 1.62 1059 2B5V48 4.9 B-1.625 2B5V80 8.1 B-1.9375 (2) 5VX500 50 6.63

20 1.62 1187 2B5V58 5.9 B-1.625 2B5V86 8.7 B-1.9375 (2) 5VX530 53 7.31

034 10 1.38 884 2BK50 4.4 H-1.375 2B5V90 9.0 B-1.9375 (2) BX51 54 5.24

15 1.62 1096 2B5V56 5.7 B-1.625 2B5V90 9.1 B-1.9375 (2) 5VX530 53 6.00

20 1.62 1187 2B5V58 5.9 B-1.625 2B5V86 8.7 B-1.9375 (2) 5VX530 53 7.31

038 10 1.38 779 1B5V60 6.1 None-1.375 1B5V136 13.7 B-1.9375 5VX650 65 7.62

15 1.62 976 2B5V52 5.3 B-1.625 2B5V94 9.5 B-1.9375 (2) 5VX530 53 6.37

20 1.62 1050 2B5V56 5.7 B-1.625 2B5V94 9.5 B-1.9375 (2) 5VX550 55 7.60

044 15 1.62 976 2B5V52 5.3 B-1.625 2B5V94 9.5 B-1.9375 (2) 5VX530 53 6.37

20 1.62 1050 2B5V56 5.7 B-1.625 2B5V94 9.5 B-1.9375 (2) 5VX550 55 7.60

25 1.88 1182 2B5V74 7.5 B-1.875 2B5V110 11.1 B-1.9375 (2) 5VX590 59 7.60

048 20 1.62 993 2B5V62 6.3 B-1.625 2B5V110 11.1 B-1.9375 (2) 5VX570 57 7.22

25 1.88 1134 2B5V80 5.9 B-1.875 2B5V124 12.5 B-1.9375 (2) 5VX630 63 7.36

30 1.88 1182 2B5V74 7.5 B-1.875 2B5V110 11.1 B-1.9375 (2) 5VX590 59 9.07

NOTE: Motor shaft speed is 1750 rpm. The fan shaft diameter is 1

⁄

inches.

Step 4 — Install Flue Hood — Flue hood is shipped

inside gas section of unit. To install, secure ﬂue hood to ac-

cess panel. See Fig. 10.

NOTE: When properly installed, ﬂue hood will line up with

combustion fan housing. See Fig. 11.

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

Fig. 9 — Air Distribution — Thru-the-Side

Fig. 10 — Flue Hood Location

Step5—TrapCondensate Drain — See Fig. 3-6

for drain location. Condensate drain is open to atmosphere

and must be trapped. Install a trapped drain at the drain lo-

cation. A trap at least 4-in. deep must be used. See Fig. 12.

Trap must be installed to prevent freeze-up.

Condensate pans are sloped so that water will completely

drain from the condensate pan to comply with indoor air qual-

ity guidelines. The condensate drain pan is ﬁtted with a 1-in.

FPT coupling.

Step 6 — Install Gas Piping — Unit is equipped for

use with natural gas. Installation must conform with local

building codes or, in the absence of local codes, with the

National Fuel Gas Code, ANSI Z223.1.

Install manual gas shutoff valve with a

⁄

-in. NPT pres-

sure tap for test gage connection at unit. Field gas piping

must include sediment trap and union. See Fig. 13. An

⁄

-in. NPT is also located on the gas manifold adjacent to

the gas valve.

Do not pressure test gas supply while connected to unit.

Always disconnect union before servicing.

IMPORTANT: Natural gas pressure at unit gas con-

nection must not be less than 5 in. wg or greater than

13.5 in. wg.

Size gas-supply piping for 0.5-in. wg maximum pressure

drop. Do not use supply pipe smaller than unit gas

connection.

Step 7 — Controls Options — The control options

that the units can provide are based on the following param-

eters: CV (constant volume) or VAV (variable air volume)

operation; stand-alone unit with ﬁeld-supplied sensors in-

stalled (CV or VAV); as a system via Carrier Comfort Sys-

tem (TEMP or VVTt); optional electronic expansion board

installed (CV or VAV); linked to the Carrier Comfort

Network; and availability of a computer and software

(ComfortWorks™ Building Supervisor, and Service Tool) or

LID-2B accessory installed to access the base control board.

See Table 3.

NOTE: Access to the base control board allows unit occu-

pancy schedules, unit timeclock, and various set points to be

changed from their factory-deﬁned default settings.

All units are equipped with a supply air thermistor (SAT)

located in the supply fan discharge and an outdoor air ther-

mistor (OAT) located in the outdoor air hood. Variable air

volume units are supplied with a return air thermistor (RAT)

located on the return air damper support.

CONSTANT VOLUME APPLICATIONS — The units, as

shipped, are operable as stand-alone units, using either a stand-

ard (mechanical or electronic) 2-stage heat, 2-stage cool ther-

mostat, or with an electronic room sensor and a timeclock to

establish unit start and stop times.

With a standard thermostat (programmable is optional),

heating and cooling operation is set by space temperature.

With a space sensor and timeclock, the machine will op-

erate at default values unless they are changed using appro-

priate input devices. The space sensor senses space tempera-

ture and may be equipped with a timed override feature, which

allows unit operation during unoccupied periods.

The space sensors may be used in multiples of 4 or 9 to

achieve space temperature averaging. The use of a space sen-

sor also allows the unit to be turned on and off from a re-

mote signal.

Features with Thermostat Control of Unit

• two-stage heating

• two-stage cooling

• control of unit using Y1, Y2, W1, W2, and G thermostat

inputs

• control of the indoor fan

• outdoor-air temperature/supply-air temperature

monitoring

• control of an outdoor air condenser fan based on outdoor-

air temperature

Fig. 11 — Combustion Fan Housing Location

Fig. 12 — Condensate Drain Trap Piping Details

(Typical Roof Curb or Slab Mount Shown)

Fig. 13 — Field Gas Piping

Table 3 — Controls Options and Conﬁgurations (Non-Thermostat Applications)

UNIT CONFIGURATION DEFAULT COOLING DEFAULT HEATING

CV or VAV Unit with SPT Sensor Unoccupied Cooling — 90 F (SPT)

Occupied Cooling — NA Unoccupied Heating — 55 F (SPT)

Occupied Heating — NA

CV Unit with SPT Sensor and Remote

Start/Stop Switch Unoccupied Cooling — 90 F (SPT)

Occupied Cooling — 78 F (SPT) Unoccupied Heating — 55 F (SPT)

Occupied Heating — 68 F (SPT)

VAV Unit Remote Start/Stop Switch Only Unoccupied Cooling — 90 F (RAT)

Occupied Cooling — 55 F (SAT) Unoccupied Heating — 55 F (RAT)

Occupied Heating — 68 F (RAT)*

VAV Unit with SPT Sensor and Remote

Start/Stop Switch Unoccupied Cooling — 90 F (SPT)

Occupied Cooling — 55 F (SAT) Unoccupied Heating — 55 F (SPT)

Occupied Heating — 68 F (RAT)*

LEGEND

CV — Constant Volume

NA — Not Available

RAT — Return-Air Temperature

SAT — Supply-Air Temperature

SPT — Space Temperature

VAV — Variable Air Volume

*With DIP Switch No. 5 conﬁgured to OPEN (Occupied Heat

Enabled).

NOTE: Space temperature sensor and remote start/stop switch are

ﬁeld-supplied.

• 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 ex-

haust controller

• support a ﬁeld test for ﬁeld checkout

• control of 2 stages of CV power exhaust

• compressor Time Guardt(power up, minimum off and on

times)

• compressor lockout during low supply-air temperature

Additional features are provided by accessing the stand-

ard unit control board via software with a computer. These

features are:

• electronic expansion board features (if installed)

• control board diagnostics

• ability to change supply air set point (economizer control)

• ability to change high outdoor temperature lockout set point

(economizer control)

• ability to change power exhaust set points

NOTE: A CV unit without a thermostat requires a ﬁeld-

supplied sensor for operation.

Features with Sensor Control of Unit (Stand-Alone Appli-

cations — Unit control is limited to CV unoccupied default

set points, 90 F for cooling, 55 F for heating. There are

2 sensor options available:

• T-55 sensor will monitor room temperature and provide

unoccupied override capability (1 hour)

• T-56 sensor will monitor room temperature, provide un-

occupied override capability (1 hour), and provide a tem-

perature offset of 5° F.

Standard features are:

• support of remote occupied/unoccupied input to start and

stop the unit

• cooling capacity control of 3 stages using economizer and

2 compressors to maintain space temperature to an occu-

pied or unoccupied set point

• enable heating or cooling during unoccupied periods as

required to maintain space temperature within the unoc-

cupied set points

• adjustment of space temperature set points of ±5° F when

using a T-56 sensor

Additional features with sensor control of unit (with com-

puter access) are:

• 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

for a timed period of 1 to 4 hours

• ability to use multiple space temperature sensors to aver-

age the space temperature

• temperature compensated start to calculate early start times

before occupancy

• access to the Display, Maintenance, Conﬁguration,

Service, and Set Point data tables through network

software

When the unit is equipped with a ﬁeld-supplied space

temperature sensor and a remote contact closure (remote start/

stop) on the base control board, the occupied default set points

will monitor unit operation. The occupied default set points

are 78 F cooling and 68 F heating. See Fig. 14 for remote

start/stop wiring.

NOTE: For units with a ﬁeld-supplied space temperature se-

sor which have not had the base unit control board accessed

via software to set an occupancy schedule, the remote start/

stop closure will allow the unit to operate in the pre-

conﬁgured occupied default set points (based on return-air

temperature) of 78 F cooling and 68 F heating. Without this

feature, the unit will control to the unoccupied default set

points of 90 F cooling and 55 F heating.

An electronic expansion board may be ﬁeld-installed to

provide the following features:

• control of modulating economizer damper to maintain in-

door air quality (IAQ) when outdoor conditions are

suitable

NOTE: The IAQ sensor must be set for current output

(4 to 20 mA), not voltage output. Ensure the jumper on

the sensor is in the upper position. See Fig. 15.

• provide discrete inputs for fan status, ﬁlter status, ﬁeld-

applied status, and demand limit

• provide an output for the external alarm light indicator

• provide power exhaust ﬁre outputs for direct control of

modulated power exhaust stages during ﬁre or smoke modes

• control of smoke control modes including evacuation, smoke

purge, pressurization, and ﬁre shutdown (modulating power

exhaust required)

When the unit is connected to the CCN (Carrier Comfort

Network), the following expansion board features can be

utilized:

• perform Demand Limit functions based on CCN loadshed

commands or the state of the discrete input

• alarm monitoring of all key parameters

• CCN protocol

• provides CCN IAQ participation

See Carrier TEMP or VVTt(Variable Volume and Tem-

perature) literature for complete TEMP (single zone) or VVT

(multi-zone) application information.

Features with Sensor Control of Unit (Network Applica-

tions) — The base control board provides, as standard, a con-

nection for use with a Carrier VVT system and can also be

integrated into a Carrier Comfort Network.

When the unit is accessed via a PC equipped with Com-

fortWorks™, Building Supervisor, or Service Tool software,

or accessory LID-2B, the following features can be

accessed:

• on-board timeclock can be programmed

• occupancy schedules can be programmed

• unit set points can be changed

• alarms can be monitored

This access is available on the base control board via a

RJ-11 phone jack or a 3-wire connection to the communi-

cation bus. See Fig. 16. The timeclock has a 10-hour mini-

mum back-up time to provide for unit power off for servic-

ing unit or during unexpected power outages. For complete

Carrier Comfort System (CCS) or Carrier Comfort Network

(CCN) features and beneﬁts, refer to the product literature.

VARIABLE AIR VOLUME (VAV) APPLICATIONS

Features with Stand-Alone Applications — The units, as

shipped, are operable as stand-alone units with the addition

of a timeclock to establish unit start and stop times.

Heating and cooling in both on and off modes is con-

trolled to default values by the base unit control. Set points

may be changed with appropriate input devices.

The control has an on-board occupancy schedule which

can be set using an input device and eliminates the need for

an external timeclock.

During both the on and off periods, cooling operation is

controlled to the supply air setting and heating is controlled

to the return air setting (or to the optional space temperature

sensor). During the on period, the supply fan runs continu-

ously. During the off period, the supply fan will be activated

if the return air sensor is outside of the set points and will

run log enough to accurately sample the space temperature.

The supply fan will then continue to run until any heating or

cooling load is satisﬁed, at which point it will turn off.

The use of a space sensor will allow for supply air reset

to conserve energy and maintain comfort. If equipped with

an override feature, the sensor will allow operation during

the off period for a ﬁxed length of time.

Base unit control supports a Heat Interlock Relay (ﬁeld

supplied) to fully open the VAV terminal devices during heat-

ing operation.

Standard features of a VAV unit with a remote start/stop

switch are:

• control board diagnostics

• control of an outdoor condenser fan based upon outdoor

air temperature

• control of modulating economizer to provide free cooling

when outdoor conditions are suitable, using supply-air tem-

perature as a set point

• support of remote occupied/unoccupied input to start or

stop the unit

• provide power exhaust output to an external power ex-

haust controller

• support supply-air temperature reset to offset supply air

set point

• support a ﬁeld test for ﬁeld check out

• support linkage to DAV systems

• cooling capacity control of up to 6 stages plus economizer

with compressors and unloaders to maintain supply air tem-

perature set point during occupied periods

• control of one stage of heat to maintain return-air tem-

perature at heating set point during occupied periods

• provide a variable frequency drive high voltage relay out-

put to enable VFD

• control of heat interlock relay

• compressor Time Guard override (power up, minimum off

and on times)

With the addition of a remote start/stop switch heating or

cooling is enabled during unoccupied periods as required to

maintain space temperature to within unoccupied set points.

Additional features may be provided with Electronic

Access to Unit Control Board. These features are:

• additional control board diagnostics

• electronic expansion board features (if installed)

• control of the economizer damper and indoor fan to obtain

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, serv-

ice, and set point data tables for interface with Building

Supervisor, ComfortWorks, or Service Tool software soft-

ware or accessory LID-2B

CONTROL

BOX

REMOTE

START/STOP

SWITCH

(FIELD-SUPPLIED)

LEGEND

Field Supplied Wiring

Fig. 14 — Field Control Remote Start/Stop

JUMPER CONNECTION

FOR VOLTAGE OUTPUT

JUMPER CONNECTION

FOR CURRENT OUTPUT

Fig. 15 — Indoor Air Quality Sensor Conﬁguration

When a VAV unit with a space temperature sensor is ac-

cessed via a computer, the following additional features are

available:

• ability to initiate timed override from T-55 sensors

• temperature compensated start to calculate early start time

before occupancy

• provide space temperature reset to reset the supply air set

point upward when the temperature falls below the occu-

pied cooling set point

An electronic expansion board may be ﬁeld-installed to

provide the following features:

• fan status

• ﬁlter status

• ﬁeld-applied status

• demand limiting

• IAQ Sensor

• OAQ Sensor

• alarm light

• ﬁre unit shutdown

• ﬁre pressurization

• ﬁre evacuation

• ﬁre smoke purge

When the unit is connected to the CCN (Carrier Comfort

Network), the following expansion board features can be

utilized:

• CCN IAQ (indoor air quality) participation

• CCN OAQ (outdoor air quality) participation

• CCN demand limit participation

• modulated power exhaust override

• ability to use multiple space temperature sensors (mul-

tiples of 4 and 9 only) to average space temperature (DAV

only)

Aﬁeld-supplied T-55 space temperature sensor can be added

to monitor room temperature and provide unoccupied over-

ride capability (1 hour).

When the unit is equipped with a ﬁeld-supplied space tem-

perature sensor and a remote contact closure (remote start/

stop) the occupied default set points will monitor unit op-

eration. The occupied default set points are 55 F (supply air)

cooling and 68 F (return air temperature) heating. See

Fig. 14 for remote start/stop wiring.

NOTE: For units without a space temperature sensor and which

have not had the base unit control board accessed via soft-

ware to set an occupancy schedule, the remote start/stop clo-

sure will allow the unit to operate in the pre-conﬁgured oc-

cupied default set points of 55 F (supply-air temperature)

cooling and 68 F (return-air temperature) heating. Without

an occupancy schedule, the unit will control to the unoccu-

pied default set points of 90 F (return air) cooling and 55 F

(return air) heating.

Features with NetworkApplications — The base control board

provides, as standard, a connection for use with a Carrier

Comfort System and can also be integrated into a Carrier

Comfort Network. When the unit is accessed via a PC equipped

with ComfortWorks™, Building Supervisor, or Service Tool

software or LID-2B accessory, the following features can be

accessed:

• on-board timeclock can be programmed

• occupancy schedules can be programmed

• unit set points can be changed

• alarms can be monitored

This access is available on the base control board via a

RJ-11 phone jack or a 3-wire connection to the communi-

cation bus. See Fig. 16. The internal timeclock has a 10-hour

minimum back-up time to provide for unit power off for ser-

vicing unit or during unexpected power outages. For com-

plete Carrier Comfort System (CCS) or Carrier Comfort

Network (CCN) features and beneﬁts, refer to the product

literature.

Step 8 — Make Electrical Connections

POWER WIRING — Units are factory wired for the voltage

shown on the unit nameplate.

When installing units, provide a disconnect per NEC

(National Electrical Code) of adequate size (MOCP [maxi-

mum overcurrent protection] of unit is on the informative

plate). All ﬁeld wiring must comply with NEC and all local

codes. Size wire based on MCA (minimum circuit amps) on

the unit informative plate. See Fig. 17 for power wiring con-

nections to the unit power terminal block and equipment ground.

The main power terminal block is suitable for use with

aluminum or copper wire. See Fig. 17. Units have circuit

breakers for compressors, fan motors, and control circuit. If

required by local codes, provide an additional disconnect switch.

Whenever external electrical sources are used, unit must be

electrically grounded in accordance with local codes, or in

absence of local codes, with NEC, ANSI C1-latest year.

All ﬁeld wiring must comply with NEC and local code

requirements.

FIELD POWER SUPPLY — Unit is factory wired for volt-

age shown on unit nameplate. See Table 4 for electrical data.

Field wiring can be brought into the unit from bottom

(through basepan and roof curb) or through side of unit (cor-

ner post next to control box).

⁄

-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 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

⁄

-in. diameter hole is provided in the con-

denser 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

⁄

-in. hole to the disconnect box and back into unit to the

main control box.

Use strain relief going into control box through 2

⁄

-in.

diameter hole provided. After wires are in unit control box,

connect to power terminal block (see Power Wiring section

above).

Low-voltage wiring must be run in watertight conduit from

the basepan to control box and through

⁄

-in. diameter hole

provided in bottom of unit control box. Field-supplied strain

relief must be used going into the box. After wiring is in

control box, make connections to proper terminals on ter-

minal blocks (see Field Control Wiring section on page 21).

Install conduit connector in unit basepan as shown in

Fig. 3-6. Route power and ground lines through connector to

terminal connections in unit control box as shown on unit

wiring diagram and Fig. 17.

Routing Through Side of Unit — Route power wiring in ﬁeld-

supplied watertight conduit into unit through 2

⁄

-in. hole.

See Fig. 17.

Use ﬁeld-supplied strain relief going into control box through

⁄

-in. diameter hole provided. After wires are in unit con-

trol box, connect to power terminal block (see Power Wiring

section on this page).

Bring low-voltage control wiring through factory-drilled

⁄

-in. diameter hole in condenser side post. Use strain relief

going into

⁄

-in. diameter hole in bottom of unit control box.

After wiring is in control box, make connection to proper

terminals on terminal blocks (see Field Control Wiring sec-

tion on page 21).

LEGEND

CCN — Carrier Comfort Network

COM — Common

D—Diode

LED — Light-Emitting Diode

N.C. — Normally Closed

N.O. — Normally Open

R—Relay

SIO — Serial Input/Output

SW — Switch

T—Terminal

Fig. 16 — Control Board Diagram

*Where X is the unit control software version number.

Table 4 — Electrical Data

UNIT

SIZE

48E

NOMNAL

VOLTAGE

(3 Ph 60 Hz)

VOLTAGE

RANGE COMPRESSOR OFM IFM POWER

EXHAUST COMBUSTION

FAN MOTOR POWER SUPPLY

No. 1 No. 2

Min Max RLA LRA RLA LRA Qty Hp FLA

(ea) Hp FLA FLA LRA FLA MCA MOCP*

024

208/230 187 254 39.1 228 25.6 160 2 1 5.3

516.7/

15.2 — — 0.96 101.8/100.3 125/125

23.6 41.6 0.96 125.4/123.9 150/150

10 30.8/

28.0 — — 0.96 115.9/113.1 150/150

23.6 41.6 0.96 139.5/136.7 175/175

15 46.2/

42.0 — — 0.96 131.3/127.1 150/150

23.6 41.6 0.96 154.9/150.7 175/175

460 414 508 19.9 114 11.5 80 2 1 2.7

5 7.6 — — 0.50 49.4 60

12.6 23.6 0.50 62.0 80

10 14.0 — — 0.50 55.8 70

12.6 23.6 0.50 68.4 80

15 21.0 — — 0.50 62.8 80

12.6 23.6 0.50 75.4 90

575 518 632 16.0 91 9.6 64 2 1 2.4

5 6.1 — — 0.50 40.5 50

12.6 23.6 0.50 53.1 60

10 11.0 — — 0.50 45.4 60

12.6 23.6 0.50 58.0 70

15 17.0 — — 0.50 51.4 60

12.6 23.6 0.50 64.0 80

028

208/230 187 254 39.1 228 39.1 228 2 1 5.3

7.5 24.2/

22.0 — — 0.96 122.8/120.6 150/150

23.6 41.6 0.96 146.4/144.2 175/175

10 30.8/

28.0 — — 0.96 129.4/126.6 150/150

23.6 41.6 0.96 153.0/150.2 175/175

15 46.2/

42.0 — — 0.96 144.8/140.6 175/175

23.6 41.6 0.96 168.4/164.2 200/200

460 414 508 19.9 114 19.9 114 2 1 2.7

7.5 11.0 — — 0.50 61.2 80

12.6 23.6 0.50 73.8 90

10 14.0 — — 0.50 64.2 80

12.6 23.6 0.50 76.8 90

15 21.0 — — 0.50 71.2 90

12.6 23.6 0.50 83.8 100

575 518 632 16.0 91 16.0 91 2 1 2.4

7.5 9.0 — — 0.50 49.8 60

12.6 23.6 0.50 62.4 70

10 11.0 — — 0.50 51.8 60

12.6 23.6 0.50 64.4 80

15 17.0 — — 0.50 57.8 70

12.6 23.6 0.50 70.4 80

030

208/230 187 254 57.1 266 39.1 228 2 1 5.3

10 30.8/

28.0 — — 0.96 151.9/149.1 200/200

23.6 41.6 0.96 175.5/172.7 225/225

15 46.2/

42.0 — — 0.96 167.3/163.1 225/225

23.6 41.6 0.96 190.9/186.7 225/225

20 59.4/

54.0 — — 0.96 180.5/175.1 225/225

23.6 41.6 0.96 204.1/198.7 250/250

460 414 508 25.6 120 19.9 114 2 1 2.7

10 14.0 — — 0.50 71.3 90

12.6 23.6 0.50 83.9 100

15 21.0 — — 0.50 78.3 100

12.6 23.6 0.50 90.9 110

20 27.0 — — 0.50 84.3 100

12.6 23.6 0.50 96.9 110

575 518 632 20.5 96 16.0 91 2 1 2.4

10 11.0 — — 0.50 57.4 70

12.6 23.6 0.50 70.0 90

15 17.0 — — 0.50 63.4 80

12.6 23.6 0.50 76.0 90

20 22.0 — — 0.50 68.4 80

12.6 23.6 0.50 81.0 100

See Legend and Notes on page 19.

Table 4 — Electrical Data (cont)

UNIT

SIZE

48E

NOMINAL

VOLTAGE

(3 Ph 60 Hz)

VOLTAGE

RANGE COMPRESSOR OFM IFM POWER

EXHAUST COMBUSTION

FAN MOTOR POWER SUPPLY

No. 1 No. 2

Min Max RLA LRA RLA LRA Qty Hp FLA

(ea) Hp FLA FLA LRA FLA MCA MOCP*

034

208/230 187 254 57.1 266 57.1 266 2 1 5.3

10 30.8/

28.0 — — 0.96 169.9/167.1 225/200

23.6 41.6 0.96 193.5/190.7 250/225

15 46.2/

42.0 — — 0.96 185.3/181.1 225/225

23.6 41.6 0.96 208.9/204.7 250/250

20 59.4/

54.0 — — 0.96 198.5/193.1 250/250

23.6 41.6 0.96 222.1/216.7 275/250

460 414 508 25.6 120 25.6 120 2 1 2.7

10 14.0 — — 0.50 77.0 100

12.6 23.6 0.50 89.6 110

15 21.0 — — 0.50 84.0 100

12.6 23.6 0.50 96.6 110

20 27.0 — — 0.50 90.0 110

12.6 23.6 0.50 102.6 125

575 518 632 20.5 96 20.5 96 2 1 2.4

10 11.0 — — 0.50 61.9 80

12.6 23.6 0.50 74.5 90

15 17.0 — — 0.50 67.9 80

12.6 23.6 0.50 80.5 100

20 22.0 — — 0.50 72.9 90

12.6 23.6 0.50 85.5 100

038

208/230 187 254 57.1 266 57.1 266 4 1 5.3

10 30.8/

28.0 — — 0.96 180.5/177.7 225/225

23.6 41.6 0.96 204.1/201.3 250/250

15 46.2/

42.0 — — 0.96 195.9/191.7 250/225

23.6 41.6 0.96 219.5/215.3 275/250

20 59.4/

54.0 — — 0.96 209.1/203.7 250/250

23.6 41.6 0.96 232.7/227.3 275/275

460 414 508 25.6 120 25.6 120 4 1 2.7

10 14.0 — — 0.50 82.4 100

12.6 23.6 0.50 95.0 110

15 21.0 — — 0.50 89.4 110

12.6 23.6 0.50 102.0 125

20 27.0 — — 0.50 95.4 110

12.6 23.6 0.50 108.0 125

575 518 632 20.5 96 20.5 96 4 1 2.4

10 11.0 — — 0.50 66.7 80

12.6 23.6 0.50 79.3 90

15 17.0 — — 0.50 72.7 90

12.6 23.6 0.50 85.3 100

20 22.0 — — 0.50 77.7 90

12.6 23.6 0.50 90.3 110

LEGEND

FLA — Full Load Amps

HACR — Heating, Air Conditioning and

Refrigeration

IFM — Indoor (Evaporator) Fan Motor

LRA — Locked Rotor Amps

MCA — Minimum Circuit Amps

MOCP — Maximum Overcurrent Protection

NEC — National Electrical Code

OFM — Outdoor (Condenser) Fan Motor

RLA — Rated Load Amps

*Fuse or HACR circuit breaker.

NOTES:

1. In compliance with NEC requirements for multimotor and combi-

nation load equipment (refer to NEC Articles 430 and 440), the

overcurrent protective device for the unit shall be fuse or HACR

breaker. Canadian units may be fuse or circuit breaker.

2. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply volt-

age is greater than 2%.

Use the following formula to determine

the percent voltage imbalance.

% Voltage Imbalance

max voltage deviation from average voltage

= 100 x average voltage

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

452 + 464 + 455

Average Voltage = 3

1371

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 452=5v

(BC) 464 − 457=7v

(AC) 457 − 455=2v

Maximum deviation is 7 v.

Determine percent voltage imbalance.

% Voltage Imbalance = 100 x 457

= 1.53%

This amount of phase imbalance is satisfactory as it is below the

maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more

than 2%, contact your local electric utility company

immediately.

Table 4 — Electrical Data (cont)

UNIT

SIZE

48E

NOMINAL

VOLTAGE

(3 Ph 60 Hz)

VOLTAGE

RANGE COMPRESSOR OFM IFM POWER

EXHAUST COMBUSTION

FAN MOTOR POWER SUPPLY

No. 1 No. 2

Min Max RLA LRA RLA LRA Qty Hp FLA

(ea) Hp FLA FLA LRA FLA MCA MOCP*

044

208/230 187 254 69.2 345 69.2 345 4 1 5.3

15 46.2/

42.0 — — 0.96 223.1/218.9 275/275

23.6 41.6 0.96 246.7/242.5 300/300

20 59.4/

54.0 — — 0.96 236.3/230.9 300/300

23.6 41.6 0.96 259.9/254.5 300/300

25 74.8/

68.0 — — 0.96 251.7/244.9 300/300

23.6 41.6 0.96 275.3/268.5 300/300

460 414 508 28.8 173 28.8 173 4 1 2.7

15 21.0 — — 0.50 96.6 125

12.6 23.6 0.50 109.2 125

20 27.0 — — 0.50 102.6 125

12.6 23.6 0.50 115.2 125

25 34.0 — — 0.50 109.6 125

12.6 23.6 0.50 122.2 150

575 518 632 26.7 120 26.7 120 4 1 2.4

15 17.0 — — 0.50 86.7 110

12.6 23.6 0.50 99.3 125

20 22.0 — — 0.50 91.7 110

12.6 23.6 0.50 104.3 125

25 27.0 — — 0.50 96.7 110

12.6 23.6 0.50 109.3 125

048

208/230 187 254 82.1 446 69.2 345 4 1 5.3

20 59.4/

54.0 — — 0.96 252.4/247.0 300/300

23.6 41.6 0.96 276.0/270.6 300/300

25 74.8/

68.0 — — 0.96 267.8/261.0 300/300

23.6 41.6 0.96 291.4/284.6 300/300

30 88.0/

80.0 — — 0.96 281.0/273.0 300/300

23.6 41.6 0.96 304.6/296.6 350/300

460 414 508 42.3 223 28.8 173 4 1 2.7

20 27.0 — — 0.50 119.5 150

12.6 23.6 0.50 132.1 150

25 34.0 — — 0.50 126.5 150

12.6 23.6 0.50 139.1 175

30 40.0 — — 0.50 132.5 150

12.6 23.6 0.50 145.1 175

575 518 632 34.6 164 26.7 120 4 1 2.4

20 22.0 — — 0.50 101.6 125

12.6 23.6 0.50 114.2 125

25 27.0 — — 0.50 106.6 125

12.6 23.6 0.50 119.2 150

30 32.0 — — 0.50 111.6 125

12.6 23.6 0.50 124.2 150

LEGEND

FLA — Full Load Amps

HACR — Heating, Air Conditioning and

Refrigeration

IFM — Indoor (Evaporator) Fan Motor

LRA — Locked Rotor Amps

MCA — Minimum Circuit Amps

MOCP — Maximum Overcurrent Protection

NEC — National Electrical Code

OFM — Outdoor (Condenser) Fan Motor

RLA — Rated Load Amps

*Fuse or HACR circuit breaker.

NOTES:

1. In compliance with NEC requirements for multimotor and combi-

nation load equipment (refer to NEC Articles 430 and 440), the

overcurrent protective device for the unit shall be fuse or HACR

breaker. Canadian units may be fuse or circuit breaker.

2. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply volt-

age is greater than 2%.

Use the following formula to determine

the percent voltage imbalance.

% Voltage Imbalance

max voltage deviation from average voltage

= 100 x average voltage

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

452 + 464 + 455

Average Voltage = 3

1371

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 452=5v

(BC) 464 − 457=7v

(AC) 457 − 455=2v

Maximum deviation is 7 v.

Determine percent voltage imbalance.

% Voltage Imbalance = 100 x 457

= 1.53%

This amount of phase imbalance is satisfactory as it is below the

maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more than

2%, contact your local electric utility company immediately.

IMPORTANT: THE VAV (variable air volume) units

use variable frequency drives, which generate, use and

can radiate radio frequency energy. If units are not in-

stalled and used in accordance with these instructions,

they may cause radio interference. They have been tested

and found to comply with limits of a Class A com-

puting device as deﬁned by FCC (Federal Communi-

cations Commission) regulations, Subpart J of Part 15,

which are designed to provide reasonable protection

against such interference when operated in a commer-

cial environment.

The unit must be electrically grounded in accordance

with local codes and NEC ANSI/NFPA 70 (National Fire

Protection Association).

Affix crankcase heater sticker (located in the installers packet)

to unit disconnect switch.

Voltage to compressor terminals during compressor op-

eration must be within the voltage range indicated on the

unit nameplate. On 3-phase units, phases must be balanced

within 2%. Contact local power company for correction of

improper voltage or phase imbalance. Unit failure due to op-

eration of unit on improper line voltage or with excessive

phase imbalance constitutes abuse and may cause damage to

unit electrical components.

On 208/230-v units, transformer no. 1 is wired for 230-v.

If 208/230-v unit is to be run with 208-v power supply, the

transformer must be rewired as follows:

1. Remove cap from red (208 v) wire.

2. Remove cap from spliced orange (230 v) wire. Discon-

nect orange wire from black unit power wire.

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 — The unit can use either a

Carrier-approved thermostat or a CCN (Carrier Comfort

Network) compatible temperature sensor. Thermostats are used

on CV (constant volume) units only. Control box diagrams

are shown in Fig. 18 and 19.

Thermostat Wiring (CV Only) — Install a Carrier-approved

accessory thermostat assembly (per current price pages) ac-

cording to the installation instructions included with the ac-

cessory or these instructions. Locate the thermostat on a solid

interior wall in the conditioned space to sense the average

temperature.

Route the thermostat cable or equivalent single leads of

colored wire from the subbase terminals to the low-voltage

connection as shown on unit label wiring diagram and in

Fig. 20.

NOTE: For wire runs up to 50 ft, use no. 18 AWG

(American Wire Gage) insulated wire (35 C minimum). For

50 to 75 ft, use no. 16 AWG insulated wire (35 C minimum).

For over 75 ft, use no. 14 AWG insulated wire (35 C mini-

mum). All wire larger than no. 18 AWG cannot be directly

connected at the thermostat and will require a junction box

and splice at the thermostat.

Set heat anticipators to 0.1 for all voltages.

Sensor Wiring (CV or VAV) — The temperature sensor is

wired into the unit control board. See Fig. 21.

The unit is controlled with a T-55 or T-56 (CV only) zone

sensor. Terminal TH (T-56) or T1 (T-55) on the sensor is

connected to T1 of the base module board. Terminal COM

(T-56) or T2 (T-55) on the sensor is connected to T2 on the

base module board. If a T-56 set point override sensor is used,

the override connection SW on the sensor is connected to T3

on the base module board.

If more than sensor is being used and averaged, sensors

must be wired in multiples of 4 or 9. See Fig. 22.

Heat Interlock Relay — VAV units require a ﬁeld-supplied

heat interlock relay (HIR) to drive the air terminal wide open

when in heat mode. Heat Interlock relay part number is

HN61KK041.

LEGEND

GND — Ground

NEC — National Electrical Code

TB — Terminal Block

NOTE: Maximum wire size for TB1 is 500 MCM.

Fig. 17 — Field Power Wiring Connections

LEGEND

C—Compressor/Contactor

CB — Circuit Breaker

DIP — Dual In-Line Package

FU — Fuse

HR — Heater Relay

IF — Indoor Fan

OF — Outdoor Fan

PEC — Power Exhaust Controller

TB — Terminal Block

TRAN — Transformer

Fig. 18 — Control Box Diagram (Sizes 024-034)

LEGEND

Fig. 20 — Field Control Thermostat Wiring

NOTE: Sensor part numbers are as follows:

T-55 — CEC0121448-01

T-56 — CEC0121503-01

Fig. 21 — Field Control Temperature Sensor Wiring

(CV or VAV Units)

C—Contactor/Compressor

CB — Circuit Breaker

DIP — Dual In-Line Package

FU — Fuse

HR — Heater Relay

IF — Indoor Fan

OF — Outdoor Fan

PEC — Power Exhaust Controller

TB — Terminal Block

TRAN — Transformer

Fig. 19 — Control Box Diagram (Sizes 038-048)

Remote Field Control — A switch closure across terminals

R and W1 on TB-3 will initiate the Occupied mode. This

can be done manually as well as through a ﬁeld-supplied

timeclock.

Service Tool, Building Supervisor, and ComfortWorks™

Software — Access to the control board can be achieved through

the terminal marked CCN via a 3-wire bus.

IMPORTANT: The default bus address is 0. The de-

fault element number is 1. Refer to CCN literature to

change the default values, if needed.

Carrier Comfort Network Interface — The 48E units can be

connected to the CCN. The communication bus wiring is sup-

plied and installed in the ﬁeld. Wiring consists of shielded,

3-conductor cable with drain wire.

The system elements are connected to the communication

bus in a daisy chain arrangement. The positive pin of each

system element communication connector must be wired to

the positive pins of the system element on either side of it,

the negative pins must be wired to the negative pins, and the

signal pins must be wired to signal ground pins. Wiring con-

nections for CCN should be made at the 3-pin plug (CCN

located at the base board). Consult CCN literature for fur-

ther information.

Conductors and drain wire must be 20 AWG minimum

stranded, tinned copper. Individual conductors must be in-

sulated with PVC, PVC/nylon, vinyl, Teﬂon, or polyethyl-

ene. An aluminum/polyester 100% foil shield and an outer

jacket of PVC, PVC/nylon, chrome vinyl, or Teﬂon with a

minimum operating temperature range of −20 C to 60 C

(−4 F to 140 F) is required. Table 5 lists cables that meet the

requirements.

Table 5 — CCN ConnectionApproved Shielded Cables

MANUFACTURER CABLE PART NO.

Alpha 2413 or 5463

American A22503

Belden 8772

Columbia 02525

SPACE TEMPERATURE AVERAGING — 4 SENSOR APPLICATION

SPACE TEMPERATURE AVERAGING — 9 SENSOR APPLICATION

Fig. 22 — Space Temperature Averaging Wiring

IMPORTANT: When connecting the CCN communi-

cation bus to a system element, use a color coding sys-

tem for the entire network to simplify installation and

checkout. See Table 6.

Table 6 — Color Code Recommendations

SIGNAL

TYPE CCN BUS CONDUCTOR

INSULATION COLOR CCN PLUG

PIN NO.

Positive (+) RED 1

Ground WHITE 2

Negative (−) BLACK 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 communica-

tion bus cables must be tied together. If the communication

bus is entirely within one building, the resulting continuous

shield must be connected to a ground at one point only.If

the communication bus cable exits from one building and

enters another, the shields must be connected to grounds at

the lightning suppressor in each building where the cable

enters or exits the building (one point per building only).

To connect the unit to the network:

1. Turn off power to the control box.

2. Cut the CCN wire and strip the ends of the red (+), white

(ground), and black (−) conductors. (If a different net-

work color scheme is used, substitute appropriate

colors.)

3. Remove the 3-pin male plug from the base module in the

main control box, and connect the wires as follows:

a. Insert and secure the red (+) wire to terminal 1 of the

3-pin plug.

b. Insert and secure the white (ground) wire to

terminal 2 of the 3-pin plug.

c. Insert and secure the black (−) wire to terminal 3 of

the 3-pin plug.

4. Insert the plug into the existing 3-pin mating connector

on the base module in the main control box.

Step 9 — Make Outdoor-Air Inlet Adjustments

ECONOMIZER

NOTE: If accessory power exhaust or barometric relief pack-

ages are being added to the unit, install power exhaust or

barometric relief before installing economizer hoods.

Economizer Hood Assembly — The economizer hood is

shipped in a package secured to the outside of the unit and

must be ﬁeld-assembled. There are 2 hoods on every unit.

The 48EW/EY units are side supply and side return. The re-

turn duct limits access to economizer ﬁlters from below.

Filter tracks (mounting angle without tabs) must be installed

correctly to allow access to economizer ﬁlters from each side.

Perform the following procedure to assemble the econo-

mizer hood:

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

⁄

-in. past the end

opposite the mounting ﬂange. See Fig. 23.

2. Assemble hood sides, top, and cross member with gas-

keted screws provided. See Fig. 24.

3. Attach 10 green speed clips (provided) to hood top.

4. Apply black seal strip (provided) to mounting ﬂanges of

hood sides being sure to cover mounting holes. See

Fig. 25.

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. 26.

6. Add gray foam strip (provided in package) to cross mem-

bers on bottom tray. See Fig. 27.

7. Place gray foam strip (provided) on inside of slotted hood

side between ﬁlter and cross member opposite the mount-

ing end. See Fig. 28.

8. Attach gray foam strip (provided) to block-off baffle on

outer face of ﬂange. See Fig. 29.

9. Remove the screws on each end and along top of damper

assembly of unit. Remove top 2 screws on each side of

ﬁlter panel under damper assembly. Set hood assembly

in place and attach to unit using these screws.

10. Attach accessory enthalpy bracket on hood side furthest

from control box end. Locate bracket on inside upper

right-hand corner of economizer hood using hood mount-

ing holes. Mount outdoor-air thermistor to enthalpy bracket

(if purchased). Attach and wire enthalpy assembly. Place

quick connects on enthalpy wires.

11. Remove screws along bottom of damper assembly. Lo-

cate and mount blockoff baffle using these screws.

12. Assemble 2 ﬁlter tracks side-by-side with the as-

sembled ends together.

13. Attach mounting angle (without tabs) to the assembled

end of the ﬁlter track. See Fig. 30.

14. Attach 6 green speed clips (provided) to mounting angles.

Engagement section of clip faces inside of rack.

15. Attach remaining mounting angle (with tabs) to other

end of the ﬁlter track with no. 10 screws provided. See

Fig. 31.

16. Place ﬁlter track assembly in bottom of hood by placing

tabbed end into slotted side (with tab on bottom) and

attaching opposite end to hood with speed clips and gas-

keted screws provided. Tabs can be hand bent after they

have been inserted into the side.

NOTE: The ﬁlter track assembly end with screws should

face away from the other hood when mounted on the

unit.

NOTE: Tabs from both ﬁlter tracks will be in the same

space. After one ﬁlter track has been inserted into hood

side, bend the tabs so they will not interfere with in-

stallation of the second hood.

17. Attach black seal strip (provided) to ﬁlter cover. Seal

strip should be applied to the center of the large ﬂange

making sure to cover holes. See Fig. 32.

18. Slide two 20 x 25-in. ﬁlters into cross members of hood

assembly. Attach ﬁlter cover over ﬁlters with screws and

speed clips provided.

Minimum Damper Position Setting — Setting of the out-

door air damper position is performed in conjunction with a

shortened version of the ﬁeld run test. This is performed by

ﬁrst opening DIP (Dual In-line Package) switch no. 4 then

no. 6. See Fig. 18 and 19 and Direct Digital Controls DIP

Switch Conﬁguration section on page 33.

HOOD SIDE

TOP

FLANGE

SEAL

STRIP

BLACK

Fig. 23 — Adding Seal Strip to Top of Hood Sides

NOTE: Left side economizer hood has mounting angle without tabs

and ﬁlter track assembled end on the opposite side.

Fig. 24 — Economizer Hood Assembly

(Right Side Economizer Hood Shown)

HOOD SIDE

MOUNTING

FLANGE

Fig. 25 — Adding Seal Strip to Mounting Flange of

Hood Sides

HOOD TO

HOOD SIDE

Fig. 26 — Adding Seal Strip to Hood Top

Mounting Flange

CROSS MEMBER

GRAY FOAM STRIP

Fig. 27 — Adding Foam Strip to Cross Member

The outdoor-air damper closes. The control allows 90 sec-

onds for the damper to close in case it is in the full open

position. Next, the indoor-fan contactor will energize. The

outdoor-air damper will remain at 0% for 30 seconds. It will

then move to the 10% position for another 30 seconds. This

will be repeated at every 10% increment for 30 seconds until

the damper reaches 100% open. Close DIP switch no. 4 dur-

ing the 30 seconds immediately after the desired outdoor air

minimum damper position. The 30-second time period is to

allow time where DIP switch no. 4 can be closed. The de-

fault value of the minimum outdoor air damper position is

20%. If the desired minimum position is 30%, allows the

damper position to go to 10% for 30 seconds, then 20% for

30 seconds, and when it reaches 30% close DIP switch

no. 4 during the 30-second period following the 30%

position.

The minimum outdoor air damper position is now set. Close

DIP switch no. 6.

ECONOMIZER SETTINGS

Accessory Enthalpy Control (Fig. 33) — The control

(HH57AC077) is mounted in the economizer hood. See

Fig. 24. The enthalpy setting adjustment is on the enthalpy

control. For maximum beneﬁt of outdoor air, set enthalpy

control to A. See Fig. 34 and 35.

Enthalpy Control Installation — The outdoor air enthalpy con-

trol is installed on the inside panel of the outdoor air hood.

The enthalpy control should be mounted when the outdoor

air hoods are assembled. To install the control, perform the

following procedure:

1. Turn off all power. Ensure disconnect is locked out.

2. Remove the economizer inlet ﬁlters from the bottom of

the right hand economizer hood. See Fig. 24. See Fig. 36

for economizer details.

3. Mount the outdoor air enthalpy sensor inside the right econo-

mizer hood on the right side panel of the hood, adjacent

to the outdoor-air thermistor.

4. Locate the red, violet, and brown wires near the outdoor

air thermistor. Remove the splice from the red and violet

wires. Remove the cap from the brown wire.

5. Install a

⁄

-in. push on terminal (ﬁeld-supplied) on the

violet and brown wires.

6. Connect a

⁄

-in. push on terminal (ﬁeld provided) to one

end of a 18-gage, 6-in. jumper wire (ﬁeld-provided). Con-

nect the other end to the red wire and attach a

⁄

-in. push

on connector (ﬁeld provided).

7. Connect the red wire with the jumper to terminal TR1.

Connect the jumper to terminal 2. Connect the brown wire

to terminal TR. Connect the violet wire to terminal 3. All

connections are on the enthalpy control.

8. Replace the economizer ﬁlters.

9. Return power to unit.

Accessory Differential Enthalpy Control (Fig. 33) — The

control (HH57AC077), in conjunction with the accessory en-

thalpy sensor (HH57AC078), controls economizer opera-

tion according to the differential enthalpy. The control is

mounted in the economizer hood. The sensor is mounted in

the return duct (48EJ/EK) or return air plenum (48EW/EY).

HOOD SIDE

(SLOTTED)

HOOD

TOP

Fig. 28 — Adding Foam Strip to Hood Side

BLOCKOFF BAFFLE

GRAY FOAM STRIP

Fig. 29 — Adding Foam Strip to Blockoff Baffle

MOUNTING ANGLE

(WITHOUT TABS)

FILTER TRACK

ASSEMBLY

Fig. 30 — Mounting Angle (Without Tabs) Attached

to Filter Track Assembly

Differential Enthalpy Sensor Installation — To install the con-

trol, perform the following procedure:

1. Turn off all power. Ensure disconnect is locked out.

2. Remove the economizer inlet ﬁlters from the bottom of

the right hand economizer hood. See Fig. 24.

3. Remove the factory-installed, 620-ohm jumper between

terminals SR and + on the enthalpy control located in-

side the outdoor air hood.

4. Connect the violet wire from the enthalpy sensor kit to

the + terminal on the enthalpy control. Connect the blue

wire from the enthalpy sensor kit to the SR terminal on

the enthalpy control.

5. Turn the enthalpy control set point potentiometer clock-

wise past the ‘‘D’’setting on the enthalpy control to con-

ﬁgure the control to operate on differential enthalpy. See

Fig. 34.

6. Remove the return-air enthalpy sensor from the acces-

sory package. Using the screws provided, mount the sen-

sor inside the return duct near the unit. Do not locate the

control too far from the unit, or the wires will not reach

from the sensor to the control. On 48EW/EY units, the

enthalpy sensor can be installed in the return air section

of the unit, under the return air dampers.

7. Route the wires from the enthalpy sensor to the return

air enthalpy control through the holes on the inside of

the hinged ﬁlter access panel. The holes are blocked by

plug buttons which should be removed.

8. Use ﬁeld-supplied wire ties to attach the violet wire to

the + terminal and the blue wire to the SR terminal.

9. Replace economizer ﬁlters.

10. Return power to unit.

Disable Economizer — For applications where the econo-

mizer will not be used (areas of high humidity), the econo-

mizer should be disabled. To disable the economizer, perform

the following:

1. Turn of power. Lock out disconnect.

2. Locate the OAT (Outdoor Air Thermostat) in the right

hand outdoor air damper area.

3. Locate the splice connecting the violet wire coming from

T24 on the base module board to the red wire coming

from T29 on the base module board. Remove the wire

nut and break the red to violet wire splice.

4. Cap off both wires. When the connection is broken the

base module is fooled into thinking that the enthalpy is

not acceptable and economizer operation is disabled.

MOUNTING ANGLE

(WITH TABS)

Fig. 31 — Mounting Angle (With Tabs) Attached to

Filter Track Assembly

BLACK SEAL STRIP

(CENTERED)

FILTER COVER

Fig. 32 — Attaching Seal Strip to Filter Cover

HH57AC077

ENTHALPY CONTROL

C7400A1004

Fig. 33 — Differential Enthalpy Control and Sensor

HH57AC078

ENTHALPY SENSOR

(USED WITH ENTHALPY

CONTROL FOR DIFFERENTIAL

ENTHALPY OPERATION)

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

on enthalpy decrease.

Fig. 34 — Wiring Connections for Solid-State

Enthalpy Control (HH57AC077)

CONTROL

CURVE

CONTROL POINT

(APPROX. DEG.)

AT 50% RH

A73 (23)

B70 (21)

C67 (19)

D63 (17)

RH — Relative Humidity

Fig. 35 — Psychrometric Chart for

Enthalpy Control

NOTE: Partitions shown indicate both side supply (EW/EY) and ver-

tical supply (EJ/EK) units.

Fig. 36 — Economizer Details

Step 10 — Position Power Exhaust/Barometric

Relief Damper Hood — All electrical connections have

been made and adjusted at the factory. The power exhaust

blowers and barometric relief dampers are shipped as-

sembled and tilted back into the unit for shipping. Brackets

and extra screws are shipped in shrink wrap around the damp-

ers. If ordered, each unit will have 4 power exhaust blowers

and motors or 4 barometric relief dampers.

1. Remove 9 screws holding each damper assembly in place.

See Fig. 37. Each damper assembly is secured with 3 screws

on each side and 3 screws along the bottom. Save screws.

Be careful when tilting blower assembly. Hoods and blow-

ers are heavy and can cause injury if dropped.

2. Pivot each damper assembly outward until edges of damper

assembly rest against inside wall of unit.

3. Secure each damper assembly to unit with 6 screws across

top (3 screws provided) and bottom (3 screws from

Step 1) of damper.

4. With screws saved from Step 1, install brackets on each

side of damper assembly.

5. Remove tape from damper blades.

VAV DUCT PRESSURE TRANSDUCER — The VAV duct

pressure transducer (VAV inverter pressure transducer) is lo-

cated behind the ﬁlter access door on the lower inner panel.

See Fig. 38. A section of ﬁeld-supplied

⁄

-in. plastic tubing

must be run from the high pressure tap on the differential

pressure switch and connected to a ﬁeld-supplied tap in the

supply-air duct. The tap is usually located

⁄

of the way out

on the main supply duct. Remove plug button in panel to

route tubing.

The low pressure tap is factory-routed to the atmo-

sphere. For a positive-pressure building, route the high tap

to building air and low tap to atmosphere. For a negative-

pressure building, route the high tap to atmosphere and the

low tap to building air.

VAV BUILDING PRESSURE TRANSDUCER — The VAV

building pressure transducer (modulating power exhaust pres-

sure transducer) is located behind the ﬁlter access door on

the lower inner panel. See Fig. 38. A section of ﬁeld-

supplied

⁄

-in. plastic tubing must be run from the high pres-

sure tap on the differential pressure switch to the conditioned

space. The pressure tube must be terminated in the condi-

tioned space where a constant pressure is required. This lo-

cation is usually in an entrance lobby so that the building

exterior doors will open and close properly. Remove plug

button in panel to route tubing.

The low pressure tap is factory-routed to the atmo-

sphere. For a positive-pressure building, route the high tap

to building air and low tap to atmosphere. For a negative-

pressure building, route the high tap to atmosphere and the

low tap to building air.

NOTES:

1. Unless otherwise speciﬁed, all dimensions are to outside of part.

2. Dimensions are in inches.

3. On 48EW,EY units, accessory barometric relief or power exhaust must be mounted in the ﬁeld-supplied return ductwork.

Fig. 37 — Barometric Relief Damper and Power

Exhaust Mounting Details

Step 11 — Install All Accessories — After all the

factory-installed options have been adjusted, install all ﬁeld-

installed accessories. Refer to the accessory installation in-

structions included with each accessory.

MOTORMASTERtIII INSTALLATION

Install Field-Fabricated Wind Baffles — Wind baffles must

be ﬁeld-fabricated for all units to ensure proper cooling cycle

operation at low-ambient temperatures. See Fig. 39 for baffle

details. Use 20-gage, galvanized sheet metal, or similar

corrosion-resistant metal for baffles. Use ﬁeld-supplied screws

to attach baffles to unit. Screws should be

⁄

-in. diameter

and

⁄

-in. long. Holes for wind baffles are pre-punched in

the unit sheet metal.

To avoid damage to the refrigerant coils and electrical

components, use recommended screw sizes only.

On 48EJ,EK,EW,EY024-034 units, the wind baffles at-

tach to ﬂanges formed on the outer sheet metal of the unit

where the condenser coil tube sheets attach.

On 48EJ,EK,EW,EY038-048 units, the wind baffles at-

tach to ﬂanges formed on the outer sheet metal of the unit

corner post. The other end of the baffle is attached to the

center panel between the condenser coil and the indoor sec-

tion. Two baffles are required for 48EJ,EK,EW,EY038-048

units.

Install Motormaster III Controls — Only one Motormaster

III control is required per unit.

Motor — The circuit no. 1 (lead compressor) outdoor-fan

motor (OFM) will need to be changed out in the ﬁeld to ac-

commodate the Motormaster III accessory. The replacement

motor part no. is HD52AK652.

On 48EJ,EK,EW,EY038-048 units, only one OFM will need

to be changed out. The no. 1 compressor is located at the left

side of the unit looking from the compressor end. The circuit

no. 2 OFMs are controlled to shut off at 55 F and turn on at

65 F outdoor-air temperature.

Sensor — Install the sensor for thermistor input control in

the location shown in Fig. 40A-C. Connect sensor leads to

the violet and gray control signal leads on the Motormaster

III control.

Signal Selection Switch — Remove the cover of the Motor-

master III control. Set the switch to accept the thermistor

sensor input signal. Set the frequency to match the unit power

supply (60 Hz).

Motormaster III Control — The recommended mounting lo-

cation is in the indoor fan section, mounted on the panel that

separates the indoor and outdoor sections. On VAV units,

this location is next to the VFD.

Do not route the Motormaster III wiring next to the VFD

on VAV units. Use a separate connector through the partition

when wiring to the OFM.

Electrical Connections

To avoid possibility of electrical shock and personal in-

jury, turn off all power to unit before making electrical

connections.

When replacing the OFM, reconnect the black, yellow, and

blue wires form the outdoor fan contactor to the black, yel-

low, and blue wires of the Motormaster III control. Run new

wires from the red, orange, and brown wires to the leads of

the new OFM. Connect the green wire from the control to

ground.

NOTE: On all 575-v units, 2 transformers (part no.

HT01AH851) must be used for each Motormaster III con-

trol to lower the supply voltage to the control to 460-v. Trans-

formers can be mounted anywhere outside the control box.

VAV — Variable Air Volume

Fig. 38 — Pressure Transducer Locations

77.7

1BOTH SIDES

CROSS-BREAK

78.7 0.5

4.62

17.167

BETWEEN

HOLES

(TYPICAL)

0.312 DIA

HOLES

NOTE: All dimensions are in inches. Material: 20 gage galvanized

steel or other non-corrosive material.

Fig. 39 — Motormaster III Baffle Details

START-UP

Use the following information and Start-Up Checklist

on page CL-1 to check out unit PRIOR to start-up.

Unit Preparation — Check that unit has been installed

in accordance with these installation instructions and appli-

cable codes.

Compressor Mounting — Loosen the compressor hold-

down bolts until sidewise movement of the washer under

each holddown bolt head can be obtained. Do not loosen

completely as bolts are self-locking and will maintain

adjustment.

Service Valves — Ensure that the suction, discharge,

and liquid line service valves are open. Damage to the com-

pressor could result if they are left closed.

Internal Wiring — Check all electrical connections in

unit control boxes; tighten as required.

Refrigerant Service Ports — Each refrigerant sys-

tem has one suction port located in the top of the compressor

motor casing. All units also have one service port on the liq-

uid line valve and one on the compressor discharge valve.

Be sure that caps on the ports are tight.

Crankcase Heaters — Crankcase heaters are ener-

gized as long as there is power to the unit, except when the

compressors are operating.

IMPORTANT: Unit power must be on for 24 hours

prior to start-up. Otherwise, damage to compressor may

result.

Variable Frequency Drive (VFD) — The variable

frequency drives are factory set. These settings include factory-

installed jumpers and software conﬁgurations. The only

ﬁeld conﬁgured set point is duct static pressure. An Opera-

tion Manual is shipped with each VAV unit. This manual should

be used if the drive needs to be customized for a particular

application.

NOTE: The VFD will always provide the proper phase

sequence to the indoor-fan motor. The indoor-fan motor op-

erates in proper rotation regardless of the phase sequence to

the unit. If, upon start-up, the outdoor fans operate back-

wards but the indoor fan operates in the correct direction,

reverse any two leads to the main terminal block. All fans

will then operate in the correct direction.

To set the duct static pressure, perform the following steps.

The factory setting is zero. The duct transducer has a range

from 0 to 5 in. wg. The transducer output is 4 to 20 mA,

therefore, 0 to 5 in. wg is proportional to the 4 to 20 mA and

must be expressed to the VFD in terms of percentage of the

frequency range. Refer to Table 7. The set point value is a

percentage of the maximum output frequency. Locate the duct

static pressure closest to that desired and use the correspond-

ing set point value. If necessary, interpolation between duct

static pressures is permissible.

Fig. 40A — Motormaster III Sensor Location

(Sizes 024-034)

Fig. 40B — MotormasterTIII Sensor Location

(Sizes 038 and 044)

Fig. 40C — Motormaster III Sensor Location

(Size 048)

To set the VFD, the VFD must be powered up; however,

since it is located near the indoor air fan, operation of the

fan is not desirable. To disable the fan, perform the follow-

ing procedure:

1. Open the indoor fan circuit breaker.

2. Remove the jumper between CC and ST on the terminal

strip of the VFD (see Fig. 41).

3. Close the indoor fan circuit breaker. The VFD now is

powered but the fan will not operate.

4. On the front of the VFD is a keypad and display which

will be used to enter the set point. To access this ﬁeld,

press the ‘‘PRG’’ key until the display reads ‘‘S.PrG’’

(Speed Group Parameters). Press the arrow key until ‘‘Sr1’’

is displayed. This is the VFD set point listed in Table 7.

5. Press the ‘‘READ/WRITE’’ key. The set point value will

be displayed. Use the up-arrow or down-arrow key to

adjust the set point value to the value desired.

6. Press the ‘‘READ/WRITE’’ key again to enter the new

value.

7. Check the factory default values.

IMPORTANT: The Carrier factory default values

for the VFD may be different than the default val-

ues of the manufacturer. Refer to the Carrier lit-

erature when checking default values. The following

default values have been changed from the manu-

facturer settings to more closely match the VFD

operation to a Carrier VAV unit.

SETUP PARAMETERS (Item 6, Point 1, Output Fre-

quency) — The default value should be 20.

JUMP FREQUENCY GROUP (Item 7, PID Set Point

Control Select) — The default value is 1.

JUMP FREQUENCY GROUP (Item 8, Proportional Gain)

— The default value is 100.

JUMP FREQUENCY GROUP (Item 9, Integral Gain)

— The default value is 50.

SPEED GROUP PARAMETERS (Item 2, Multi-Speed

Run Frequency No. 1) — The factory setting is 30.

SPEED GROUP PARAMETERS (Item 2, Fire Speed

Override Frequency) — The factory setting is 60.

8. Open the indoor fan circuit breaker.

9. Replace the jumper between CC and ST on the terminal

strip of the VFD.

10. Close the indoor fan circuit breaker; the VFD now is

powered and the fan will operate.

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).

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 two exhaust fans.

When the economizer position reaches 75% open, the base

module activates the other two exhaust fans. The fans will

turn off when the economizer closes below the same points.

The economizer position set points that trigger the exhaust

fans can be modiﬁed, but only through use of the Service

Tool, Comfort Works, or Building Supervisor software. If

single-stage operation is desired, adjust the economizer set

points to identical values at the desired point to activate all

exhaust fans.

The optional modulating power exhaust (VAV standard,

CV optional) is controlled by a modular electronic se-

quencer system. This system consists of a model R353 sig-

nal input module and 4 model S353 staging modules. The

signal input module receivesa0to10vdcsignal 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 bya0to10vdcsignal. A factory-

installed hose at the ‘‘Lo’’ connection leads to atmosphere,

and a ﬁeld-supplied hose must be connected to the ‘‘Hi’’con-

nection and led into the building to a point where building

pressure is to be controlled (positive-pressure building). There

is a plug button in the bulkhead just above the transducers,

for use in leading the hoses into the building via the return

air ductwork.

There are 3 adjustments at the R353 module, all of which

have been factory set. In the center of the circuit board is

a set of 4 pins with a jumper, labeled J2. This determines the

mode of operation. The bottom two pins must be jumpered

for direct operation. Direct operation means that the stag-

ing modules are activated in sequence as the input signal

increases.

Table 7 — VFD Supply Air Pressure Set Point

PRESSURE

(in. wg) CONTROL

(mA) VFD

SET POINT

04.0 0

0.25 4.8 3

0.50 5.6 6

0.75 6.4 9

1.00 7.2 12

1.25 8.0 15

1.50 8.8 18

1.75 9.6 21

2.00 10.4 24

2.25 11.2 27

2.50 12.0 30

2.75 12.8 33

3.00 13.6 36

3.25 14.4 39

3.50 15.2 42

VFD — Variable Frequency Drive

(SS2) (SS3)

FLA FLB FLC P24 RCH LOW FM AM PP RR IV CC ST F R CC SS1 JOG AD2 RST CC

+–

DPDP JUMPERS

NOTE: Terminal strip is located inside the VFD at the bottom.

Fig. 41 — VFD Factory-Installed Jumpers

At the upper right corner of the board is a set of 5 pins and

jumper, which determines the time constant for the control.

The time constant is the delay in response built into the con-

trols. The jumper should be on the middle or bottom two

pins, for the maximum time constant. The delay can be

decreased, if desired, by moving the jumper progressively

upward, always jumpering adjacent pins.

At the lower left corner of the board below the terminal

strip is a resistor marked R27. This must be removed in

order to obtain the 0 to 10 vdc signal output. There will not

be a resistor on a factory-supplied module, but a resistor may

be present on a replacement module and must be removed.

The R353 module has a terminal block with 7 connec-

tions available for wiring. The 2 right-hand terminals are for

the 24 vac and common connections. The next 2 terminals

are for the 0 to 10 vdc signal. Consult the wiring label for

wire identiﬁcation if replacing the module. The 3 left-hand

terminals are not used for this application.

The S353 module has an LED (light-emitting diode), a set

of 4 jumper pins, and 2 potentiometers. The LED will light

whenever the module is activated, providing a visual indi-

cation of the number of exhaust fans running. The jumper

pins are arranged in a square format. Two jumpers are used

to determine the mode of operation (direct or reverse). The

2 jumpers must be arranged horizontally for direct action

(factory set).

At the top of the module are two potentiometers. The left

potentiometer adjusts the offset. The right potentiometer

adjusts the differential. The potentiometers are factory set

for a nominal 0 in. wg building pressure.

The offset set point is deﬁned as the point at which a mod-

ule turns off a fan, and is measured in terms of percent of the

input signal. For control purposes, 0 offset is at an arbitrary

‘‘ﬂoor’’ which is established at 10% of the input signal, or

1 vdc. In this example, the ﬁrst stage will turn off at 30%

(3 vdc), and the offset potentiometer will be set at 20%.

The second stage will turn off at 50% signal (5 vdc), and the

offset potentiometer will be set at 40%. The fourth stage is

at the maximum 75% offset, which equates to 85% signal

or 8.5 vdc. The offset potentiometer is calibrated in 10%

increments.

Table 8 relates building pressure to signal level.

Table 8 — Potentiometer Signal Levels

BUILDING PRESSURE

(in. wg) SIGNAL LEVEL

(vdc)

−0.50 2

−0.25 4

0.00 6

0.25 8

0.50 10

If the building pressure is controlled at 0 in. wg, offset of

the ﬁrst stage should be set at 50%, which equates to 60%

of the input signal, or 6 vdc. The other stages can then be set

as desired between 50% and 75%.

The default offset set points for modulating power ex-

haust are shown in Table 9.

The differential set point is the difference between the

turn off point and the turn on point for each module. It also

is calibrated in terms of percent of input signal, and has a

range of 1% to 7%. The differential potentiometer is cali-

brated in 1% increments, and is factory set at approximately

3%. It is recommended to leave the set point at 3%, to mini-

mize cycling of the fans.

The offset and differential potentiometers have been fac-

tory set for atmospheric pressure. Do not change these

settings until there is some experience with the building. In

most cases the factory settings will be satisfactory. How-

ever, if the building pressure is not being maintained as de-

sired, then some minor adjusting on a trial and error basis

can be made.

Direct Digital Controls DIP Switch Conﬁgura-

tion — The Direct Digital Control (DDC) board must be

conﬁgured for each application. The DDC board is conﬁg-

ured through the DIP switches located on the board. There

are 8 DIP switches which conﬁgure 8 different applications

of the DDC. See Table 10. DIP switch 1 is on the left of the

block. DIP switch 8 is on the right of the block. To open a

DIP switch, push the switch up with suitable tool (small-

blade screwdriver). To close a DIP switch, push the switch

down. Factory settings are shown in Table 11.

The DIP switch conﬁgurations are as follows:

• DIP switch 1 conﬁgures the unit to operate as a VAV or

CV unit

• DIP switch 2 conﬁgures the unit to use a space sensor (VAV

units) or a thermostat (CV units)

• DIP switch 3 conﬁgures the DDC for use with an elec-

tronic expansion board

• DIP switch 4 is used to ﬁeld test the unit

• DIP switch 5 is used to enable occupied heating (VAV units)

or specify the type of power exhaust (CV units)

• DIP switch 6 conﬁgures the Time Guardtoverride 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 con-

ditioner operation.

Crankcase Heater — Units are equipped with crank-

case heaters. Crankcase heaters are energized as long as there

is power supplied to unit. Crankcase heaters deenergize while

compressors are running.

IMPORTANT: To prevent damage to compressors, crank-

case heater should be energized 24-hours prior to

start-up.

Evaporator Fan — Fan belt and ﬁxed pulleys are factory-

installed. See Tables 12-16 for fan performance and motor

limitations data. Remove tape from fan pulley, and be sure

that fans rotate in the proper direction. See Table 17 for air

quantity limits. Static pressure drop for power exhaust is neg-

ligible. To alter fan performance, see Evaporator Fan

Performance Adjustment section on page 46.

Condenser Fans and Motors — Condenser fans and

motors are factory set. Refer to Condenser-Fan Adjustment

section on page 47 as required. Be sure that fans rotate in

the proper direction. Fan no. 2 (sizes 024-034) and fans

no. 3 and 4 (sizes 038-048) are cycled on the outdoor-air

temperature.

Table 9 — Power Exhaust Default Set Points

STAGE OFFSET DIFFERENTIAL OFF VOLTAGE ON VOLTAGE OFF STATIC PRESSURE

(in. wg)

150% 3% 6.0 6.3 0.00

255% 3% 6.5 6.8 0.06

360% 3% 7.0 7.3 0.12

464% 3% 7.4 7.7 0.18

Table 10 — DIP Switch Conﬁguration

SETTING 1 2 3 4 5 6 7 8

OPEN VAV

VAV — Space Sensor

Installed Expansion

Board Field Test

VAV —

Occupied

Heat

Enabled

Time GuardTOverride

Gas Heat Heat Pump

Operation

CV — CCN or Sensors

Used

CV —

Modulated

Power

Exhaust

IN CONJUNCTION

WITH FIELD TEST

— Set Minimum

Damper Position

CLOSED CV

VAV — No Space Sensor

Base Control

Board Only Field Test

OFF

VAV —

Occupied

Heat

Disabled Time Guard Override

OFF Electric Heat Air Conditioner

Operation

CV — Thermostat

CV —

Constant

Volume

Power

Exhaust

LEGEND

CCN — Carrier Comfort Network

CV — Constant Volume

VAV — Variable Air Volume

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 VAV functions.

3. When the unit is ﬁeld-tested (DIP switch 4 to OPEN), the function

of DIP switch 6 changes and it is used to set the minimum damper

position.

Table 11 — DIP Switch Factory Settings

UNIT 12345678

48EJ,EW Closed Closed Closed Closed Closed Closed Open Closed

48EK,EY Open Closed Closed Closed Closed Closed Open Closed

Table 12 — Fan Performance, 48EJ/EK024-034 — Vertical Discharge Units

(For EW/EY units, reduce net available external static pressure by 0.3 in. wg)

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

4,000 340 0.83 416 1.17 480 1.52 537 1.90 588 2.29 635 2.69 679 3.11 720 3.53

5,000 384 1.25 453 1.61 513 1.99 566 2.39 615 2.79 660 3.21 703 3.64 742 4.08

6,000 432 1.79 495 2.19 550 2.59 600 3.01 647 3.43 690 3.87 730 4.31 769 4.77

7,000 483 2.48 540 2.91 591 3.33 638 3.77 682 4.22 723 4.67 762 5.14 799 5.61

8,000 536 3.33 588 3.78 635 4.23 679 4.69 720 5.16 759 5.64 797 6.12 832 6.61

8,250 549 3.57 600 4.02 646 4.48 690 4.95 730 5.42 769 5.90 806 6.39 841 6.88

9,000 590 4.34 637 4.82 681 5.30 722 5.78 762 6.27 799 6.77 834 7.27 868 7.77

10,000 645 5.54 689 6.04 729 6.54 768 7.04 805 7.56 840 8.07 874 8.59 906 9.12

11,000 701 6.92 741 7.44 779 7.96 816 8.49 850 9.03 884 9.56 916 10.10 947 10.65

12,000 757 8.49 795 9.04 830 9.59 865 10.14 898 10.69 929 11.25 960 11.81 990 12.37

12,500 786 9.36 822 9.92 856 10.47 890 11.03 922 11.60 953 12.16 983 12.73 1012 13.31

13,000 814 10.28 849 10.84 883 11.41 915 11.98 946 12.56 976 13.13 1006 13.71 1034 14.30

13,750 857 11.75 890 12.34 922 12.92 953 13.51 983 14.10 1012 14.69 1041 15.28 1068 15.88

14,000 871 12.27 904 12.86 936 13.45 966 14.05 996 14.64 1025 15.23 1053 15.83 1080 16.43

15,000 929 14.50 960 15.10 990 15.71 1019 16.33 1047 16.94 1074 17.55 1101 18.17 1127 18.79

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

4,000 759 3.97 796 4.42 831 4.87 865 5.34 897 5.81 929 6.30 959 6.79 988 7.28

5,000 780 4.53 816 4.99 851 5.45 884 5.93 916 6.41 946 6.90 976 7.40 1005 7.91

6,000 805 5.23 840 5.70 874 6.18 906 6.67 937 7.16 968 7.66 997 8.17 1025 8.69

7,000 834 6.09 868 6.57 901 7.07 932 7.56 962 8.07 992 8.58 1020 9.10 1048 9.63

8,000 866 7.10 899 7.60 930 8.11 961 8.62 990 9.14 1019 9.67 1047 10.20 1074 10.74

8,250 874 7.38 907 7.89 938 8.40 968 8.92 998 9.44 1026 9.97 1054 10.50 1081 11.04

9,000 901 8.29 932 8.80 963 9.33 992 9.86 1021 10.39 1049 10.93 1076 11.48 1102 12.03

10,000 938 9.65 968 10.18 997 10.72 1026 11.27 1054 11.82 1081 12.37 1107 12.93 1133 13.49

11,000 977 11.19 1006 11.75 1035 12.30 1062 12.87 1089 13.43 1115 14.00 1141 14.57 1166 15.15

12,000 1019 12.94 1047 13.51 1074 14.08 1100 14.66 1126 15.24 1152 15.83 1177 16.42 1201 17.01

12,500 1040 13.88 1067 14.46 1094 15.05 1120 15.63 1146 16.22 1171 16.82 1195 17.41 — —

13,000 1062 14.88 1089 15.47 1115 16.06 1140 16.66 1166 17.25 1190 17.86 — — — —

13,750 1095 16.48 1121 17.08 1147 17.68 1172 18.29 1196 18.90 — — — — — —

14,000 1106 17.04 1132 17.64 1157 18.25 1182 18.86 — — — — — — — —

15,000 1152 19.41 1177 20.04 1200 20.66 — — — — — — — — — —

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

3.4 3.6 3.8

Rpm Bhp Rpm Bhp Rpm Bhp

4,000 1017 7.79 1045 8.30 1072 8.82

5,000 1033 8.42 1061 8.94 1087 9.46

6,000 1053 9.21 1080 9.73 1106 10.27

7,000 1075 10.16 1102 10.69 1127 11.24

8,000 1100 11.28 1126 11.83 1151 12.38

8,250 1107 11.59 1133 12.14 1158 12.69

9,000 1128 12.58 1153 13.14 1178 13.70

10,000 1158 14.06 1183 14.63 — —

11,000 1190 15.74 ————

12,000 ——————

12,500 ——————

13,000 ——————

13,750 ——————

14,000 ——————

15,000 ——————

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. Variable Air Volume units will operate down to 70 cfm/ton. Per-

formance at 70 cfm/ton is limited to unloaded operation and may

be additionally limited by edb (entering dry bulb) and ewb (enter-

ing wet bulb) conditions.

Table 13 — Fan Performance, 48EJ,EK038,044 — Vertical Discharge Units

(For EW/EY units, reduce net available external static pressure by 0.5 in. wg)

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

7,000 429 1.70 484 2.40 536 2.70 584 3.10 630 3.50 674 3.90 716 4.30 756 4.80

8,000 475 2.36 525 3.09 571 3.49 616 3.90 658 4.31 699 4.74 738 5.17 776 5.61

9,000 523 3.11 567 3.97 610 4.39 651 4.82 690 5.26 728 5.71 765 6.16 801 6.62

10,000 571 4.00 612 5.01 651 5.46 689 5.91 725 6.37 761 6.84 795 7.31 829 7.79

11,000 620 5.04 658 6.22 694 6.69 729 7.17 763 7.65 796 8.14 829 8.64 860 9.14

12,000 670 6.24 705 7.61 738 8.10 771 8.60 803 9.11 834 9.62 865 10.13 894 10.65

13,000 720 7.61 752 9.19 784 9.70 814 10.23 844 10.75 874 11.29 902 11.82 931 12.36

14,000 771 9.15 801 10.97 830 11.51 859 12.05 887 12.60 915 13.15 942 13.71 969 14.27

15,000 822 10.88 850 12.95 877 13.52 904 14.08 931 14.65 957 15.22 983 15.80 1008 16.38

16,000 873 12.80 899 15.16 925 15.74 951 16.33 976 16.92 1001 17.51 1025 18.11 1049 18.71

17,000 924 14.91 949 17.59 974 18.20 998 18.80 1022 19.41 1045 20.03 1069 20.64 1092 21.26

18,000 976 17.24 999 20.26 1023 20.88 1046 21.51 1068 22.14 1091 22.77 1113 23.41 1135 24.05

19,000 1027 19.77 1050 23.17 1072 23.82 1094 24.46 1115 25.11 1137 25.76 1158 26.42 1179 27.07

20,000 1079 22.53 1100 26.33 1122 27.00 1142 27.66 1163 28.33 1183 29.00 — — — —

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

7,000 794 5.20 832 5.62 868 6.06 903 6.52 937 6.98 971 7.44 1003 7.92 1035 8.40

8,000 813 6.06 848 6.52 883 6.98 916 7.45 949 7.92 981 8.40 1012 8.89 1042 9.38

9,000 835 7.09 869 7.56 902 8.04 934 8.53 965 9.02 995 9.52 1025 10.02 1054 10.53

10,000 862 8.28 893 8.77 925 9.27 955 9.77 985 10.28 1014 10.79 1043 11.31 1071 11.84

11,000 891 9.64 921 10.15 951 10.67 980 11.19 1008 11.71 1036 12.24 1064 12.78 1090 13.32

12,000 924 11.18 952 11.71 980 12.24 1008 12.78 1035 13.32 1062 13.87 1088 14.42 1114 14.98

13,000 958 12.91 986 13.45 1012 14.01 1039 14.56 1064 15.13 1090 15.69 1115 16.26 1140 16.83

14,000 995 14.83 1021 15.40 1046 15.97 1071 16.55 1096 17.13 1120 17.71 1144 18.29 1168 18.89

15,000 1033 16.96 1058 17.55 1082 18.14 1106 18.73 1130 19.33 1153 19.93 1176 20.54 1199 21.14

16,000 1073 19.31 1097 19.92 1120 20.52 1143 21.14 1165 21.75 1188 22.37 — — — —

17,000 1114 21.88 1137 22.51 1159 23.13 1181 23.76 — — — — — — — —

18,000 1156 24.69 1178 25.33 1199 25.98 — — — — — — — — — —

19,000 ————————————————

20,000 ————————————————

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

3.4 3.6 3.8

Rpm Bhp Rpm Bhp Rpm Bhp

7,000 1066 8.88 1096 9.38 1125 9.88

8,000 1072 9.88 1101 10.39 1130 10.90

9,000 1083 11.04 1111 11.56 1139 12.08

10,000 1098 12.37 1125 12.90 1152 13.44

11,000 1117 13.86 1143 14.41 1169 14.96

12,000 1139 15.54 1164 16.11 1189 16.68

13,000 1164 17.41 1188 17.99 — —

14,000 1191 19.48 — — — —

15,000 ——————

16,000 ——————

17,000 ——————

18,000 ——————

19,000 ——————

20,000 ——————

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. Variable Air Volume units will operate down to 70 cfm/ton. Per-

formance at 70 cfm/ton is limited to unloaded operation and may

be additionally limited by edb (entering dry bulb) and ewb (enter-

ing wet bulb) conditions.

Table 14 — Fan Performance, 48EJ,EK048 — Vertical Discharge Units

(For EW/EY units, reduce net available external static pressure by 0.5 in. wg)

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

9,000 528 3.20 572 4.00 615 4.40 656 4.90 695 5.30 733 5.80 769 6.20 805 6.70

10,000 577 4.10 617 5.10 657 5.50 694 6.00 731 6.40 766 6.90 801 7.40 834 7.90

11,000 627 5.10 664 6.30 700 6.80 735 7.30 769 7.70 802 8.20 835 8.70 866 9.20

12,000 677 6.30 711 7.70 745 8.20 778 8.70 809 9.20 841 9.70 871 10.20 901 10.80

13,000 728 7.71 760 9.31 791 9.83 822 10.35 851 10.88 881 11.42 909 11.95 938 12.50

14,000 779 9.28 809 11.11 838 11.65 867 12.20 895 12.75 923 13.31 950 13.87 976 14.43

15,000 830 11.03 858 13.13 886 13.69 913 14.26 939 14.83 966 15.41 991 15.99 1017 16.57

16,000 882 12.97 908 15.36 934 15.95 960 16.54 985 17.13 1010 17.73 1034 18.33 1058 18.93

17,000 934 15.12 959 17.83 983 18.44 1008 19.05 1031 19.66 1055 20.28 1078 20.89 1101 21.52

18,000 986 17.47 1010 20.53 1033 21.16 1056 21.79 1078 22.42 1101 23.06 1123 23.70 1145 24.34

19,000 1038 20.05 1061 23.49 1083 24.13 1105 24.78 1126 25.44 1147 26.09 1169 26.75 1190 27.41

20,000 1091 22.84 1112 26.69 1133 27.36 1154 28.03 1174 28.70 1195 29.37 — — — —

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2

Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp Rpm Bhp

9,000 839 7.10 873 7.62 905 8.10 937 8.59 968 9.08 999 9.57 1028 10.08 1057 10.58

10,000 866 8.40 898 8.85 929 9.34 959 9.85 989 10.36 1018 10.87 1047 11.39 1075 11.91

11,000 897 9.70 927 10.24 956 10.76 985 11.28 1013 11.81 1041 12.34 1068 12.87 1095 13.41

12,000 930 11.30 958 11.82 986 12.36 1014 12.90 1041 13.44 1067 13.99 1093 14.54 1119 15.10

13,000 965 13.04 992 13.59 1019 14.15 1045 14.71 1071 15.27 1096 15.84 1121 16.41 1146 16.98

14,000 1002 14.99 1028 15.56 1054 16.14 1079 16.71 1103 17.30 1127 17.88 1151 18.47 1175 19.06

15,000 1041 17.15 1066 17.74 1090 18.34 1114 18.93 1138 19.53 1161 20.13 1184 20.74 — —

16,000 1082 19.52 1105 20.14 1128 20.75 1151 21.37 1174 21.99 1196 22.61 — — — —

17,000 1124 22.14 1146 22.77 1168 23.40 1190 24.03 — — — — — — — —

18,000 1166 24.98 1188 25.63 — — — — — — — — — — — —

19,000 ————————————————

20,000 ————————————————

AIRFLOW

(Cfm)

AVAILABLE EXTERNAL STATIC PRESSURE (in. wg)

3.4 3.6 3.8

Rpm Bhp Rpm Bhp Rpm Bhp

9,000 1086 11.10 1114 11.61 1141 12.14

10,000 1102 12.44 1129 12.97 1155 13.51

11,000 1122 13.96 1147 14.51 1173 15.06

12,000 1144 15.66 1169 16.23 1194 16.80

13,000 1170 17.56 1194 18.14 — —

14,000 1198 19.66 ————

15,000 ——————

16,000 ——————

17,000 ——————

18,000 ——————

19,000 ——————

20,000 ——————

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. Variable Air Volume units will operate down to 70 cfm/ton. Per-

formance at 70 cfm/ton is limited to unloaded operation and may

be additionally limited by edb and ewb conditions.

Table 15 — Fan Performance — Power Exhaust

48EJ,EK,EW,EY024-048 (20 THRU 45 TONS)

Airﬂow

(Cfm)

Low Speed Medium Speed High Speed

208 v 230, 460, 575 v 208 v 230, 460, 575 v 208 v 230, 460, 575 v

ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts ESP Bhp Watts

6,500 0.32 2.82 3160 0.70 2.98 3340 — —- —- —- —- —- —- —- —- —- —- —-

6,700 0.23 2.87 3220 0.63 3.03 3400 0.60 3.01 3380 0.82 3.23 3620 —- —- —- —- —- —-

6,900 0.17 2.92 3270 0.59 3.09 3460 0.55 3.07 3440 0.78 3.28 3680 —- —- —- —- —- —-

7,100 0.13 2.93 3290 0.56 3.11 3490 0.49 3.12 3500 0.73 3.34 3740 —- —- —- —- —- —-

7,300 0.09 2.97 3330 0.53 3.15 3530 0.43 3.18 3560 0.68 3.39 3800 —- —- —- —- —- —-

7,500 —- —- —- 0.51 3.19 3580 0.39 3.24 3630 0.64 3.44 3860 —- —- —- —- —- —-

7,700 —- —- —- 0.48 3.23 3620 0.33 3.27 3670 0.59 3.48 3900 0.60 3.69 4140 0.73 3.98 4460

7,900 —- —- —- 0.45 3.27 3670 0.27 3.32 3720 0.54 3.52 3950 0.56 3.74 4190 0.69 4.02 4510

8,100 —- —- —- 0.40 3.33 3730 0.22 3.36 3770 0.49 3.57 4000 0.51 3.78 4240 0.65 4.07 4560

8,500 —- —- —- —- —- —- 0.17 3.47 3890 0.40 3.67 4120 0.41 3.83 4290 0.56 4.12 4620

8,900 —- —- —- —- —- —- 0.00 3.58 4010 0.30 3.77 4230 0.31 3.93 4410 0.47 4.23 4740

9,300 —- —- —- —- —- —- —- —- —- 0.22 3.87 4340 0.20 4.07 4560 0.37 4.37 4900

9,700 —- —- —- —- —- —- —- —- —- 0.16 3.95 4430 0.11 4.17 4670 0.30 4.47 5010

10,100 —- —- —- —- —- —- —- —- —- 0.12 4.03 4520 0.04 4.25 4770 0.23 4.56 5110

10,500 —- —- —- —- —- —- —- —- —- —- —- —- —- —- —- 0.17 4.66 5220

10,900 —- —- —- —- —- —- —- —- —- —- —- —- —- —- —- 0.12 4.75 5330

11,300 —- —- —- —- —- —- —- —- —- —- —- —- —- —- —- 0.07 4.80 5380

11,700 —- —- —- —- —- —- —- —- —- —- —- —- —- —- —- 0.04 4.83 5420

LEGEND

Bhp — Brake Horsepower

ESP — External Static Pressure (in. wg)

Watts — Input Watts to Motor

Table 16 — Motor Limitations

STANDARD EFFICIENCY MOTORS

Nominal

Hp Maximum

Bhp Maximum Amps Maximum

Watts Motor

Efficiency

230 460 575

55.9 14.6 — — 5,030 87.5

5.9 — 7.9 6.0 5,030 87.5

7.5 8.7 22.0 — — 7,334 88.5

9.5 — 12.0 10.0 8,008 88.5

10 10.2 28.0 — — 8,502 89.5

11.8 — 14.6 12.0 9,836 89.5

15 15.3 43.8 — — 12,543 91.0

18.0 — 21.9 19.0 14,756 91.0

20 22.4 62.0 — — 18,363 91.0

23.4 — 28.7 23.0 19,183 91.0

25 28.9 72.0 — — 23,511 91.7

29.4 — 37.4 31.0 23,918 91.7

30 35.6 95.0 — — 28,742 92.4

34.7 — 48.0 47.0 28,015 92.4

HIGH EFFICIENCY MOTORS

Nominal

Hp Maximum

Bhp Maximum Amps Maximum

Watts Motor

Efficiency

230 460

55.9 15.8 — 4,918 89.5

5.9 — 7.9 4,918 89.5

7.5 8.7 22.0 — 7,078 91.7

9.5 — 12.0 7,728 91.7

10 10.2 28.0 — 8,298 91.7

11.8 — 15.0 9,600 91.7

15 15.3 43.8 — 12,273 93.0

18.0 — 21.9 14,439 93.0

20 22.4 58.2 — 17,853 93.6

23.4 — 28.7 18,650 93.6

25 28.9 73.0 — 23,034 93.6

29.4 — 36.3 23,432 93.6

30 35.6 82.6 — 28,374 93.6

34.7 — 41.7 27,656 93.6

BHP — Brake Horsepower

NOTE: Extensive motor and electrical testing on the Carrier units has ensured that the full horsepower range of the motor can be utilized with

conﬁdence. Using your fan motors up to the horsepower ratings shown on the Motor Limitations table will not result in nuisance tripping or premature

motor failure. Unit warranty will not be affected.

Table 17 — Air Quantity Limits

UNIT

48EJ,EK,EW,EY

MINIMUM HEATING

AIRFLOW

(Low Heat)

MINIMUM HEATING

AIRFLOW

(High Heat)

MINIMUM COOLING

AIRFLOW (VAV)

AT FULL LOAD

OPERATION

MINIMUM COOLING

AIRFLOW (CV) MAXIMUM

AIRFLOW

024 5730 5950 2000 6,000 10,000

028 5730 5950 2500 7,500 12,500

030 5730 5950 2750 8,250 13,750

034 5730 5950 3000 9,000 15,000

038 7360 9820 3500 10,500 17,500

044 7360 9820 4000 12,000 20,000

048 7360 9820 4500 13,500 22,500

LEGEND

CV — Constant Volume

VAV — Variable Air Volume

Return-Air Filters — Check that correct ﬁlters are in-

stalled in ﬁlter tracks (see Table 1). Do not operate unit with-

out return-air ﬁlters.

Filter Replacement — To replace ﬁlters, open ﬁlter ac-

cess door (marked with label). Remove inner access panel.

Remove plastic ﬁlter retainer in between ﬁlter tracks by slid-

ing and pulling outward. Remove ﬁrst ﬁlter by sliding it out

of the opening in ﬁlter track. Locate ﬁlter removal tool, which

is shipped next to the return air dampers. Use the ﬁlter re-

moval tool to remove the rest of the ﬁlters.

Outdoor-Air Inlet Screens — Outdoor-air inlet screens

must be in place before operating unit.

EconomizerAdjustment — Remove ﬁlter access panel.

Check that outdoor-air damper is closed and return-air damper

is open.

Economizer operation and adjustment are described in

Sequence of Operation section on this page; and Minimum

Damper Position Setting section on page 24.

Gas Heat — Verify gas pressures before turning on heat

as follows:

1. Turn off ﬁeld-supplied manual gas stop, located external

to unit.

2. Connect pressure gage to supply gas tap, located on ﬁeld-

supplied manual shutoff valve (see Fig. 13 on page 13).

3. Connect pressure gage to manifold pressure tap on unit

gas valve.

4. Supply gas pressure must not exceed 13.5 in. wg. Check

pressure at ﬁeld-supplied shut-off valve.

5. Turn on manual gas stop and initiate a heating demand.

Jumper R to W1 in the control box to initiate heat. On

VAV units, the RAT (Return-Air Temperature) must be

less than or equal to 68 F for heating to be energized. Use

the ﬁeld test procedure to verify heat operation. After the

unit has run for several minutes, verify that incoming pres-

sure is 5.0 in. wg or greater, and that the manifold pres-

sure is 3.5 in. wg. If manifold pressure must be adjusted,

refer to Gas Valve Adjustment section on page 47.

Sequence of Operation

NOTE: Unit is shipped with default values that can be changed

through Service Tool, Building Supervisor, or Comfort-

Works™ software. See Table 18 for default values.

COOLING, CONSTANT VOLUME (CV) UNITS — On

power up, the control module will activate the initialization

software of the control board. The initialization software then-

reads DIP switch no. 1 position to determine CV or VAV

operation. Next, DIP switch no. 2 is read to determine if the

control is thermostat or sensor type operation. If switch 2 is

open,then sensors are employed. If switch no. 2 is closed,

thermostat is employed. Initialization clears all alarms and

alerts, remaps the input/output database for CV operation,

sets maximum heat stages to 2, and sets maximum cool stages

to 3. The control reads DIP switch no. 3 and if open, then it

sets the internal ﬂag for expansion mode operation.

The ﬁrst time power is sent to the control board after a

power outage, power up takes 5 minutes plus a random 1 to

63 seconds.

The TSTAT function performs a thermostat based control

by monitoring Y1, Y2, W1, W2, and G inputs. These func-

tions control stages cool1, cool2, heat1, heat2, and indoor

fan, respectively. If TSTAT function is NOT selected, the

control determines the occupancy state on the Time Sched-

ules or with remote occupied/unoccupied input. If tempera-

ture compensated start is active, the unit will be controlled

as in the Occupied mode. User-deﬁned set points are shown

in Table 18.

The occupied or unoccupied comfort set points must be

selected and the space temperature offset input will be used,

if present. The Occupied Heat set point default value is

68 F. The Occupied Cool set point default value is 78 F. The

Unoccupied Heat set point default value is 55 F. The Un-

occupied Cool set point value is 90 F. The control board will

set appropriate operating mode and fan control. The control

board will turn on indoor fan, if in Occupied mode, or de-

termine if unit is in Unoccupied mode and the space tem-

perature is outside of the unoccupied comfort set points,

(Unoccupied Heat or Unoccupied Cool).

The control board will then monitor space temperature against

comfort set points and control heating or cooling stages as

required. If system is in the Occupied mode, the economizer

will operate as required. If the system is in Unoccupied

mode, the system will perform nighttime free cool and IAQ

(indoor air quality) pre-occupancy purge as required (when

functions are enabled via software). Whenever the DX

(di-rect expansion) cooling is requested, the outdoor fan will

operate.

The control board will operate economizer, run diagnos-

tics to monitor alarms/alerts at all times, and respond to CCN

communications to perform any conﬁgured network POC

(product outboard control) functions such as time and outdoor-

air temperature broadcast and Global occupancy broadcast.

When the optional expansion I/O board is employed, it will:

perform periodic scan and maintain database of expanded

I/O points, perform Fire/Smoke control (power exhaust re-

quired); and if in Occupied mode perform IAQ control and

monitor fan, ﬁlter, demand limit, and ﬁeld-applied status (with

accessories).

If thermostats are used to energize the G input, the control

will turn on indoor fan without delay and open economizer

dampers to minimum position.

Table 18 — User Deﬁned Set Points

SET POINT

NAME FORMAT DESCRIPTION LIMITS DEFAULT

OHSP xx.xF Occupied Heat Set Point 55 to 80 F 68 F

OCSP xx.xF Occupied Cool Set Point 55 to 80 F 78 F

UHSP xx.xF Unoccupied Heat Set Point 40 to 80 F 55 F

UCSP xx.xF Unoccupied Cool Set Point 75 to 95 F 90 F

SASP xx.xF Supply Air Set Point 45 to 70 F 55 F

OATL xx.xF Hi OAT Lockout Temperature 55 to 75 F 65 F

NTLO xx.xF Unoccupied OAT Lockout Temperature 40 to 70 F 50 F

RTIO xx.x Reset Ratio 0 to 10 3

LIMT xx.xF Reset Limit 0 to 20° F 10%

MDP xxx% Minimum Damper Position 0 to 100% 20%

LOWMDP xxx% Low Temperature Minimum

Damper Position Override 0 to 100% 100%

IAQS xxxx IAQ Set Point 1 to 5000 PPM 650 PPM

UHDB xx.xF Unoccupied Heating Deadband 0 to 10° F 1° F

UCDB xx.xF Unoccupied Cooling Deadband 0 to 10° F 1° F

LTMP xxx% Low Temp. Min. Position 0 to 100% 10%

HTMP xxx% High Temp. Min. Position 0 to 100% 35%

PES1 xxx% CV Power Exhaust Stage 1 Point 0 to 100% 25%

PES2 xxx% CV Power Exhaust Stage 2 Point 0 to 100% 75%

LEGEND

CV — Constant Volume

IAQ — Indoor Air Quality

OAT — Outdoor-Air Temperature

If thermostats are used to deenergize the G input, the con-

trol board will turn off indoor fan without any delay and close

economizer dampers.

When cooling, G must be energized before cooling can

operate. The control board determines if outdoor conditions

are suitable for economizer cooling using the standard out-

door air thermistor. For economizer to function for free cool-

ing, the enthalpy must be low, the outdoor air must equal to

or less than the High Outdoor Air Temperature Lockout (de-

fault is 65 F), the SAT (supply-air temperature) thermistor is

NOT in alarm, and outdoor air reading is available. When

these conditions are satisﬁed, the control board will use econo-

mizer as the ﬁrst stage of cooling.

When Y1 input is energized, the economizer will be modu-

lated to maintain SAT at the deﬁned set point. The default is

55 F. When SAT is above the set point, the economizer will

be 100% open. When SAT is below the set point, the econo-

mizer will modulate between minimum and 100% open po-

sition. When Y2 is energized, the control will turn on com-

pressor no. 1 and continue to modulate economizer as described

above. If the Y2 remains energized and the SAT reading re-

mains above the set point for 15 minutes, compressor no. 2

will turn on. If Y2 is deenergized at any time, only the last

stage of compression that was energized will be turned off.

If outdoor conditions are not suitable for economizer cool-

ing, the economizer will go to minimum position and cycle

compressor no. 1 and 2 based on demand from Y1 and Y2

respectively. The compressors will be locked out when the

SAT temperature is too low (less than 40 F for compressor

no. 1 and less than 45 F for compressor no. 2.) After a com-

pressor is locked out, it can restart after normal time guard

period.

The Time Guardtfunction maintains a minimum off time

of 5 minutes, a minimum ON time of 10 seconds, and a

minimum delay before starting the second compressor of

10 seconds.

When heating, the heat stages respond to the demand from

W1 and W2 of the thermostat input. Heating and cooling

will be mutually locked out on demand on a ﬁrst call basis.

The heating and the cooling functions cannot be operating

simultaneously.

COOLING, VARIABLE VOLUME UNITS — On power up,

the control module will activate the initialization software

of the control board. The initialization software then reads

DIP switch no. 1 position to determine CV or VAV opera-

tion. Initialization clears all alarms and alerts, re-maps the

input/output database for VAV operation, sets maximum heat

stages to 1 and sets maximum cool stages to 6. The control

reads DIP switch no. 3 and if open, then it sets the internal

ﬂag for expansion mode operation.

The control board will determine if an interface (linkage)

is active and if the unit will operate in a Digital Air Volume

(DAV) mode. In a DAV system, the room terminals are equipped

with microprocessor controls that give commands to the base

unit module. If an interface is active, the control will replace

local comfort set points, space and return air temperatures

and occupancy status with the linkage data supplied.

The control board will determine occupancy status from

Time Schedules (if programmed), Remote Occupied/

Unoccupied input, global occupancy, or DAV. If tempera-

ture compensated start is active, the unit will be controlled

as in the Occupied mode.

NOTE: The temperature compensated start is a period of time

calculated to bring the unit on while unoccupied to reach the

occupied set point when occupancy occurs.

The control board will set the appropriate operating mode

and fan control. The control board will turn VFD on if Oc-

cupied mode is evident.

For units equipped with a start/stop switch only (no space

temperature sensor), if unoccupied and valid return-air tem-

perature reading is available (either from a sensor or DAV),

the control will monitor return-air temperature against Un-

occupied Heat and Cool set points.

For units with a start-stop switch and a space temperature

sensor, the control board will start the VFD whenever SPT

is outside of the set points (Unoccupied Heat or Unoccupied

Cool). The VFD may also be started by nighttime thermostat

via remote Occupied/Unoccupied input or by a temperature

compensated start algorithm. When VFD is running in a nor-

mal mode, the control will start heating or cooling as re-

quired to maintain supply-air temperature at the supply air

set point plus the reset (when enabled). The reset value is

determined by SAT (supply-air temperature) reset and/or space

temperature reset algorithms. The space temperature reset is

only available when enabled through software.

When cooling, the control will energize the power ex-

haust enable output to the external power exhaust controller,

when power exhaust is used.

If occupied, the control will perform economizer control

(economizer control same as described above for CV units).

If unoccupied, the control will perform nighttime free cool

and IAQ pre-occupancy purge as required (when enabled

through software). When DX (direct expansion) cooling is

called, the outdoor fans will always operate.

The control will run continuous diagnostics for alarms/

alerts; respond to CCN communications and perform any con-

ﬁgured network POC (product outboard controls) functions

such as time and outdoor-air temperature broadcast and glo-

bal broadcast; and perform Fire/Smoke control if equipped

with power exhaust.

GAS HEATING, CONSTANT VOLUME (CV) UNITS —

The gas heat units incorporate 2 separate systems to provide

gas heat. Each system incorporates its own induced-draft mo-

tor, Integrated Gas Control (IGC) board, 2 stage gas valve,

manifold, etc. The systems are operated in parallel; for ex-

ample, when there is a call for ﬁrst stage heat, both induced-

draft motors operate, both gas valves are energized, and both

IGC boards initiate spark.

All of the gas heating control is performed through the

IGC boards (located in the heating section). The base mod-

ule board serves only to initiate and terminate heating

operation.

The base module board is powered by 24 vac. When the

thermostat or room sensor calls for heating, power is sent

from the base module board to W on each of the IGC boards.

An LED on the IGC board will be on during normal opera-

tion. A check is made to ensure that the rollout switches and

limit switches are closed and the induced-draft motors are

not running. The induced-draft motors are then energized,

and when speed is proven with the hall effect sensor on the

motor, the ignition activation period begins. The burners will

ignite within 5 seconds.

When ignition occurs the IGC board will continue to moni-

tor the condition of the rollout and limit switches, the hall

effect sensor, as well as the ﬂame sensor. If the unit is con-

trolled through a room thermostat set for fan auto., 45 sec-

onds after ignition occurs, the indoor-fan motor will be

energized and the outdoor-air dampers will open to their mini-

mum position. If for some reason the overtemperature limit

opens prior to the start of the indoor fan blower, on the next

attempt, the 45-second delay will be shortened to 5 seconds

less than the time from initiation of heat to when the limit

tripped. Gas will not be interrupted to the burners and heat-

ing will continue. Once modiﬁed, the fan on delay will not

change back to 45 seconds unless power is reset to the con-

trol. If the unit is controlled through a room sensor, the in-

door fan will be operating in the Occupied mode and the

outdoor-air dampers will be in the minimum position.

If the unit is controlled with a room sensor in the Unoc-

cupied mode, the indoor fan will be energized through the

IGC board with a 45-second delay and the outside-air damp-

ers will move to the IAQ position (generally closed in the

Unoccupied mode). If IAQ is not enabled, dampers will move

to the minimum position.

When additional heat is required, W2 closes and initiates

power to the second stage of the main gas valves. When the

thermostat is satisﬁed, W1 and W2 open and the gas valves

close interrupting the ﬂow of gas to the main burners. If the

call for W1 lasted less than 1 minute, the heating cycle will

not terminate until 1 minute after W1 became active. If the

unit is controlled through a room thermostat set for fan auto.,

the indoor-fan motor will continue to operate for an addi-

tional 45 seconds then stop and the outdoor-air dampers will

close. If the overtemperature limit opens after the indoor

motor is stopped within 10 minutes of W1 becoming inac-

tive, on the next cycle the time will be extended by 15 sec-

onds. The maximum delay is 3 minutes. Once modiﬁed, the

fan off delay will not change back to 45 seconds unless power

is reset to the control. If the unit is controlled through a room

sensor, the indoor fan will be operating in the Occupied mode

and turned off after 45 seconds in the Unoccupied mode.

GAS HEATING, VARIABLE AIR VOLUME (VAV) UNITS

— All of the gas heating control is performed through the

integrated gas control (IGC) board. The base module board

serves only to initiate and terminate heating operation.

NOTE: The unit is factory-conﬁgured for disabled occupied

heating. DIP switch 5 is used to enable occupied heating (DIP

switch 5 set to OPEN).

The base module board is powered by 24 vac. When there

is a call for heating (either Morning Warm-Up, Unoccupied,

or Occupied modes), power is sent from the base module

board to W on each of the IGC boards and W2 of the main

gas valve. When heating, the control board will energize a

ﬁeld-supplied heat interlock relay output to drive the VAV

terminal boxes wide open. The HIR is not required on a DAV

system. See Fig. 42. In the Occupied mode the indoor-fan

motor will be operating and the outdoor-air dampers will be

in the minimum position. In the Unoccupied mode the indoor-

fan motor will be off, but will energize 45 seconds after the

call for heat and the outdoor-air dampers will move to the

IAQ Unoccupied position (generally set to closed in the Un-

occupied mode). The duct pressure sensor will signal to the

variable frequency drive to operate at full speed since all

terminals have been driven open. An LED on the IGC board

will be on during normal operation. A check is made to en-

sure that the rollout switches and limit switches are closed

and the induced-draft motors are not running. The induced-

draft motors are then energized and when speed is proven

with the hall effect sensor on the motor, the ignition activa-

tion period begins. The burners will ignite within 5 seconds.

When ignition occurs the IGC board will continue to moni-

tor the condition of the rollout and limit switches, the hall

effect sensor, and the ﬂame sensor.

If the call for heat lasted less than 1 minute, the heating

cycle will not terminate until 1 minute after heat became ac-

tive. When heating is satisﬁed, the power will be interrupted

to the IGC board and W1 and W2 of the main gas valve. If

the unit is controlled through a room sensor, the indoor fan

will be operating in the Occupied mode and turned off after

45 seconds in the Unoccupied mode.

MORNING WARM-UP (VAV only) (PC Accessed/CCN

Operation) — Morning warm-up occurs when the control

has been programmed to turn on heat prior to the Occupied

mode to be ready for occupancy mode. Morning warm-up is

a condition in VAV systems that occurs when the Tempera-

ture Compensated Start algorithm calculates a biased occu-

pied start time and the unit has a demand for heating. The

warm-up will continue into the occupied period as long as

there is a need for heat. During warm-up, the unit can con-

tinue heating into the occupied period, even if occupied heat-

ing is disabled. When the heating demand is satisﬁed, the

warm-up condition will terminate. To increase or decrease

the heating demand, use Service Tool software to change the

Occupied Heating set point.

NOTE: To utilize Morning Warm-Up mode, the unit occu-

pancy schedule must be accessed via Service Tool, Building

Supervisor, or ComfortWorks™ software or accessory LID-

2B. The PC can access the base control board via the 3-wire

communication bus or via an RJ-11 connection to the CCN

terminal on the base control board. See Fig. 16.

MORNING WARM-UP (VAV Only) (Stand-Alone Opera-

tion) — When the unit operates in stand-alone mode, morn-

ing warm-up occurs when the unit is energized in Occupied

mode and return-air temperature (RAT) is below 68 F. Warm-up

will not terminate until the RAT reaches 68 F. The heat in-

terlock relay output is energized during morning warm-up.

(A ﬁeld-installed 24-vdc heat interlock relay is required.) The

output will be energized until the morning warm-up cycle is

complete. Refer to Fig. 42 for heat interlock relay wiring.

SPACE TEMPERATURE RESET SENSOR (VAV Only) —

An accessory space temperature sensor wired to terminals

T1 and T2 on the control module is required. Space tem-

perature reset is used to reset the supply-air temperature set

point of a VAV system higher, as the space temperature falls

below the Occupied Cool set point. As the space tempera-

ture falls below the Occupied Cool set point, the supply-air

temperature will be reset upward as a function of the reset

ratio. (Default is 3.) Reset ratio is expressed in degrees change

in supply-air temperature per degree of space temperature

change. A reset limit will exist which will limit the maxi-

mum number of degrees the supply-air temperature may be

raised. (Default is 10 F.) Both the reset ratio and the reset

limit are user deﬁnable. The sequence of operation is as

follows:

1. The on/off status of the unit supply fan is determined.

2. If the fan is ‘‘on,’’ the sequence will check if the system

is occupied.

3. If the system is occupied, the sequence will determine if

the reset option is enabled.

4. If the reset option is enabled, the sequence will read the

space temperature and compare it to the Occupied Cool

set point. If the temperature is below the Occupied Cool

set point, the algorithm will compute the reset value and

compare this value against the reset limit. If it is greater

than the reset limit, the sequence will use the reset limit

as the reset value.

BASE MODULE

CONTROL BOARD

T29

COM

TRAN2

SECONDARY

24 VOLT

CB4

3.2 AMPS

INDOOR FAN RELAY

HIR

FIELD

INSTALLED

(HN61KK040)

(24V, 9.5VA)

LEGEND

CB — Circuit Breaker

COM — Common

HIR — Heat Interlock Relay

T—Terminal

TRAN — Transformer

Fig. 42 — Heat Interlock Relay Wiring

4-20 mA

INPUT

FIELD

SUPPLIED

INPUT DEVICE

BASE MODULE

CONTROL BOARD

(+) T11

(–) T12

LEGEND

T—Terminal

NOTE: The 4 to 20 mA input is a ﬁeld-supplied non-

Carrier EMS (Energy Management System) device.

Fig. 43 — Space Temperature Reset Wiring

mA INPUT DEG. F RESET

40.00

51.25

62.50

73.75

85.00

96.25

10 7.50

11 8.75

12 10.00

13 11.25

14 12.50

15 13.75

16 15.00

17 16.25

18 17.50

19 18.75

20 20.00

Space Temperature Reset Example — The occupied cooling

set point is set to 73 F. The Reset Ratio is set to 5. The Reset

Limit is set to 20° F. The Reset Ratio determines how many

degrees F the temperature is reset. At 72 F, the supply tem-

perature will be reset 5 degrees higher. At 71 F, the supply

temperature will be reset 10 degrees higher. At 70 F, the sup-

ply temperature will be reset 15 degrees higher. At 69 F, the

supply temperature will be reset 20 degrees higher and the

Reset Limit will have been reached.

SUPPLY AIR TEMPERATURE RESET — Supply air tem-

perature reset is used to reset the supply air temperature util-

ity. A 4 to 20 mA signal (ﬁeld-supplied) is required. The re-

set option does not require enabling.

POWER EXHAUST OPERATION — The optional power

exhaust packages are factory- or ﬁeld-installed with vertical

units and optionally installed in the return air ductwork for

horizontal applications. The standard (offered with constant

volume or variable air volume units) and the modulating power

exhaust (offered on VAV units) are the two packages offered.

The modulating power exhaust package is equipped with a

ﬁeld-adjustable static pressure controller to stage up to 4 power

exhaust stages which will maintain a building static pres-

sure. The blue controller located in the control box below

the control board can be adjusted, by removing the covers

and adjusting the set point dial to the desired building pres-

sure. The blue controller monitors the 4 individual sequenc-

ers which activate the 4 individual power exhaust motors.

The standard power exhaust package controls up to 2 stages

of power exhaust to maintain building pressure. The power

exhaust package can be conﬁgured to deliver positive or nega-

tive building pressure. These power exhaust stages are staged

according to a percentage of the economizer dampers

position. Default values are 25% for Stage 1 and 75% for

Stage 2. This package has set points that are adjustable

through software (Service Tool, Building Supervisor, or

ComfortWorks™).

SMOKE CONTROL MODES — The 48EJ,EK,EW,EY units

with an optional expansion board perform ﬁre and smoke

control modes. The expansion board provides 4 modes which

can be used to control smoke within the conditioned area.

The modes of operation are ﬁre shutdown, pressurization,

evacuation, and smoke purge. See Table 19.

SMOKE DETECTOR — A smoke detector can be used to

initiate ﬁre shutdown. This can be accomplished by a set of

normally closed pilot relay contacts which will interrupt power

from the 24-v transformer, secondary ‘‘B’’ terminal to the

control circuit breaker (CB4). See Fig. 44. The wire that con-

nects these two points is white and labeled ‘‘W78.’’

NOTE: On standard gas models, the indoor fan will con-

tinue to run 45 seconds after the call for heat has been ter-

minated. If ﬁre shutdown is initiated the fan will stop im-

mediately. No 45-second delay will occur.

The smoke detector may be mounted in the return air duct

or the supply duct. Carrier does not make recommendations

as to speciﬁc smoke detector location due to liability

considerations.

INDOOR AIR QUALITY CONTROL — The accessory ex-

pansion board and accessory IAQ sensor are required for IAQ

control. The Carrier sensors operate witha4to20mAsig-

nal. The 4 to 20 mA signal is connected to T11 (+) and T12

(−) on the expansion board for the IAQ sensor, and T13 (+)

and T14 (−) on the expansion board for the OAQ (Outdoor

Air Quality) sensor. The sensor is ﬁeld-mounted and wired

to the expansion board installed in the unit main control box.

The IAQ sensor must be powered by a ﬁeld-supplied 24-v

power supply (ungrounded). Do not use the unit 24-v power

supply to power the sensor.

Once installed, the sensor must be enabled. The sensor is

conﬁgured with default values which may be changed through

network access software. To work properly, the IAQ sensor

high and low reference points for the sensor that is used must

match the conﬁgured values. The expansion board reacts to

a 4 to 20 mA signal from the IAQ sensor. The low reference

(4 mA output) must be conﬁgured to the minimum IAQ sen-

sor reading. The high reference (20 mAoutput) must be con-

ﬁgured to the maximum IAQ sensor reading.

The IAQ sensor can be conﬁgured to either low or high

priority. The priority value can be changed by the user. The

default is low.

Low priority — When the priority is set to low, the initial

control is to the IAQ set point, but the outside air damper

position will change to its minimum position when the fol-

lowing conditions occur:

• CV units with sensor — when the space temperature is

greater than the occupied cooling set point plus 2° F or

when the space temperature is less than the occupied

heating set point minus 2° F.

• VAV units and CV units with thermostat — when the

supply-air temperature is less than the supply-air tem-

perature set point minus 8° F or when the supply-air

temperature is greater than the supply air temperature

set point plus 5° F for 4 minutes.

Table 19 — Smoke Control Modes

DEVICE PRESSURIZATION SMOKE PURGE EVACUATION FIRE SHUTDOWN

Economizer 100% 100% 100% 0%

Indoor Fan/VFD ON ON OFF OFF

Power Exhaust (all outputs) OFF ON ON OFF

Heat Stages OFF OFF OFF OFF

HIR ON ON OFF OFF

LEGEND

HIR — Heat Interlock Relay

VFD — Variable Frequency Drive

Fig. 44 — Field-Supplied Smoke Detector Wiring

• When the outdoor air quality is greater than the outdoor

air quality set point (ppm)

High priority — When the priority is set to high, the IAQ

set point controls the outside air damper exclusively, with

no regard to comfort conditioning.

TIME GUARDtCIRCUIT — The Time Guard function (built

into the rooftop control board) maintains a minimum off time

of 5 minutes, a minimum on time of 10 seconds, and a

10-second delay between compressor starts.

CRANKCASE HEATER — Unit main power supply must

remain on to provide crankcase heater operation. The crank-

case heater in each compressor keeps oil free of refrigerant

while compressor is off.

HEAD PRESSURE CONTROL — Each unit has a fan cy-

cling, outdoor thermostat to shut off the outdoor-fan mo-

tor(s) at 55 F (one outdoor-fan motor on 024-034 units and

two outdoor fan motors on 038-048 units). The head pres-

sure control permits unit to operate with correct condensing

temperatures down to 35 F outdoor-air temperature.

MOTORMASTERtIII CONTROL — The Motormaster

III Solid-State Head Pressure Control is a ﬁeld-installed ac-

cessory fan speed control device actuated by a temperature

sensor. It is speciﬁcally designed for use on Carrier equip-

ment and controls the condenser-fan motor speed in re-

sponse to the saturated condensing temperature. For outdoor

temperatures down to −20 F, it maintains condensing tem-

perature at 100 F. Refer to the accessory Motormaster in-

stallation instructions for more information.

CAPACITY CONTROL, COOLING — The cooling capac-

ity staging tables are shown in Tables 20 and 21.

Table 20 — Cooling Capacity Staging Table, CV Units

with 2 Compressors

Stages

Economizer 23

Compressor 1 off off on on

Compressor 2 off off off on

NOTE: On CV units that require additional unloading, add suction pres-

sure unloaders to Compressor 1 only.

Table 21 — Cooling Capacity Staging Table VAV Units

with 2 Compressors and 2 Unloaders*

Stages

0123456

Compressor 1 offonononononon

Unloader 1 off on on off on on off

Unloader 2 off on off off on off off

Compressor 2 off off off off on on on

*40 ton units have only one unloader.

FIELD TEST — The ﬁeld test program is initiated by mov-

ing up DIP switch no. 4 to the OPEN position. The outdoor-

air damper will close. The control allows 90 seconds for the

damper to close in case it was in the full open position. Next,

the indoor-fan contactor will be energized, and the outside-

air damper will begin to open to its default value of 20% and

stay at that position for a short period of time. The outdoor-

air damper will then open to its full open position and stay

at that position for a short period of time. The outdoor-air

damper will then close.

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. If the unit

is equipped with the Integrated Gas Control (IGC) board,

the indoor fan will continue to operate for an additional

30 seconds after deenergizing the circuit.

The ﬁeld test is then complete.

SERVICE

Before performing service or maintenance operations on

unit, turn off main power switch to unit. Electrical shock

could cause personal injury.

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

⁄

-in.-20x

⁄

-in. long bolt.

See Fig. 45.

Fig. 45 — Door Latch

To open, loosen the latch bolt using a

⁄

-in. wrench. Pivot

the latch so it is not in contact with the door. Open the door.

To shut, reverse the above procedure.

NOTE: Disassembly of the top cover may be required under

special service circumstances. It is very important that the

orientation and position of the top cover be marked on the

unit prior to disassembly. This will allow proper replace-

ment of the top cover onto the unit and prevent rainwater

from leaking into the unit.

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.

Cleaning — Inspect unit interior at beginning of each heat-

ing and cooling season and as operating conditions require.

Remove unit side panels and/or open doors for access to unit

interior.

MAIN BURNERS — At the beginning of each heating sea-

son, inspect for deterioration or blockage due to corrosion or

other causes. Observe the main burner ﬂames and adjust if

necessary. Check spark gap. See Fig. 46. Refer to Main Burn-

ers section on page 48.

FLUE GAS PASSAGEWAYS — The ﬂue collector box and

heat exchanger cells may be inspected by removing gas sec-

tion access panel (Fig. 3-6), ﬂue box cover, collector box,

and main burner assembly (Fig. 47 and 48). Refer to Main

Burners section on page 48 for burner removal sequence. If

cleaning is required, clean all parts with a wire brush. Re-

assemble using new cerafelt high-temperature insulation for

sealing.

COMBUSTION-AIR BLOWER — Clean periodically to as-

sure proper airﬂow and heating efficiency. Inspect blower

wheel every fall and periodically during heating season. For

the ﬁrst heating season, inspect blower wheel bi-monthly to

determine proper cleaning frequency.

To inspect blower wheel, remove heat exchanger access

panel. Shine a ﬂashlight into opening to inspect wheel. If

cleaning is required, remove motor and wheel assembly by

removing screws holding motor mounting plate to top of com-

bustion fan housing (Fig. 47 and 48). The motor, scroll, and

wheel assembly can be removed from the unit. Remove scroll

from plate. Remove the blower wheel from the motor shaft

and clean with a detergent or solvent. Replace motor and

wheel assembly.

EVAPORATOR COIL — Remove access panels and clean

as required with commercial coil cleaner.

CONDENSER COIL — Clean condenser coil annually and

as required by location and outdoor-air conditions. Inspect

coil monthly; clean as required.

CONDENSATE DRAIN — Check and clean each year at

start of cooling season. In winter, keep drains and traps dry.

FILTERS — Clean or replace at start of each heating and

cooling season, or more often if operating conditions re-

quire. Refer to Table 1 for type and size.

NOTE: The unit requires industrial grade throwaway ﬁlters

capable of withstanding face velocities up to 625 fpm.

OUTDOOR-AIR INLET SCREENS — Clean screens with

steam or hot water and a mild detergent. Do not use dis-

posable ﬁlters in place of screens. See Fig. 24 for location of

screens (ﬁlter track assembly).

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

⁄

and

⁄

of sight glass during steady operation.

If oil charge is above

⁄

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

IMPORTANT: Do not use reclaimed oil or oil that has

been exposed to the atmosphere. Refer to Carrier Stand-

ard Service Techniques Manual, Chapter 1, Refriger-

ants section, for procedures to add or remove oil.

FAN SHAFT BEARINGS — Lubricate bearings at least ev-

ery 6 months with suitable bearing grease. Do not over grease.

Typical lubricants are given below:

MANUFACTURER LUBRICANT

Texaco Regal AFB-2*

Mobil Mobilplex EP No. 1

Sunoco Prestige 42

Texaco Multifak 2

*Preferred lubricant because it contains rust and oxidation inhibitors.

CONDENSER-AND EVAPORATOR-FAN MOTOR BEAR-

INGS — The condenser- and evaporator-fan motors have

permanently-sealed bearings, so no ﬁeld lubrication is

necessary.

Fig. 46 — Spark Gap Adjustment

Evaporator Fan Performance Adjustment

(Fig. 49) — Fan motor pulleys are designed for speed shown

in Table 1 (factory speed setting).

IMPORTANT: Check to ensure that the unit drive

matches the duct static pressure using Tables 12-14.

To change fan speeds, change pulleys.

To align fan and motor pulleys:

1. Shut off unit power supply.

2. Loosen fan shaft pulley bushing.

3. Slide fan pulley along fan shaft.

4. Make angular alignment by loosening motor from mount-

ing plate.

5. Retighten pulley.

Evaporator Fan Service and Replacement

1. Shut off unit power supply.

2. Remove supply-air section panels.

3. Remove belt and blower pulley.

4. Loosen setscrews in blower wheels.

5. Remove locking collars from bearings.

6. Remove shaft.

7. Remove venturi on opposite side of bearing.

8. Lift out wheel.

9. Reverse above procedure to reinstall fan.

10. Check and adjust belt tension as necessary.

Belt Tension Adjustment — To adjust belt tension:

1. Shut off unit power supply.

2. Loosen motor mounting nuts and bolts. See Fig. 50.

3. Loosen fan motor nuts.

4. Turn motor jacking bolts to move motor mounting plate

left or right for proper belt tension. A slight bow should

be present in the belt on the slack side of the drive while

running under full load.

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.

NOTES:

1. Torque set screws on blower wheel to 70 in. lbs ± 2 in. lbs.

2. Torque set screw on propeller fan to 15 in. lbs ± 2 in. lbs.

3. Dimensions are in inches.

Fig. 47 — Typical Gas Heating Section

Fig. 48 — Gas Heat Section Details

Evaporator-Fan Motor Replacement

1. Shut off unit power supply.

2. Remove upper outside panel and open hinged door to

gain access to motor.

3. Fully retract motor plate adjusting bolts.

4. Loosen the two rear (nearest the evaporator coil) motor

plate nuts.

5. Remove the two front motor plate nuts and carriage bolts.

6. Slide motor plate to the rear (toward the coil) and re-

move fan belt(s).

7. Slide motor plate to the front and hand tighten one of

the rear motor plate nuts (tight enough to prevent the

motor plate from sliding back but loose enough to allow

the plate to pivot upward).

8. Pivot the front of the motor plate upward enough to al-

low access to the motor mounting hex bolts and secure

in place by inserting a prop.

9. Remove the nuts from the motor mounting hex bolts and

remove motor.

10. Reverse above steps to install new motor.

Condenser-Fan Adjustment

1. Shut off unit power supply.

2. Remove fan guard.

3. Loosen fan hub setscrews.

4. Adjust fan height on shaft using a straightedge placed across

venturi and measure per Fig. 51.

5. Fill hub recess with permagum if rubber hubcap is

missing.

6. Tighten setscrews and replace panel(s).

7. Turn on unit power.

Power Failure — The economizer damper motor is a

spring return design. In event of power failure, dampers will

return to fully closed position until power is restored.

Refrigerant Charge — Amount of refrigerant charge

is listed on unit nameplate and in Table 1. Refer to Carrier

GTAC II; Module 5; Charging, Recovery, Recycling, and

Reclamation section for charging methods and procedures.

Unit panels must be in place when unit is operating dur-

ing charging procedure.

NOTE: Do not use recycled refrigerant as it may contain

contaminants.

NO CHARGE — Use standard evacuating techniques. After

evacuating system, weigh in the speciﬁed amount of

refrigerant (refer to Table 1).

LOW CHARGE COOLING — Using appropriate cooling

charging chart (see Fig. 52 and 53), add or remove refrig-

erant until conditions of the appropriate chart are met. Note

that charging chart is different from those normally used. An

accurate pressure gage and temperature sensing device are

required. Measure liquid line pressure at the liquid line serv-

ice valve using pressure gage. Connect temperature sensing

device to the liquid line near the liquid line service valve

and insulate it so that outdoor ambient temperature does not

affect reading.

Using the above temperature and pressure readings, ﬁnd

the intersect point on the appropriate cooling charging chart.

If intersection point on chart is above line, add refrigerant.

If intersection point on chart is below line, carefully reclaim

some of the charge. Recheck suction pressure as charge is

adjusted.

NOTE: Indoor-air cfm must be within normal operating range

of unit. All outdoor fans must be operating.

Thermostatic Expansion Valve (TXV) — Each cir-

cuit has a TXV. The TXV is nonadjustable and is factory set

to maintain 10 to 13° F superheat leaving the evaporator coil.

The TXV controls ﬂow of liquid refrigerant to the evapo-

rator coils.

Gas Valve Adjustment

NATURAL GAS — The 2-stage gas valve opens and closes

in response to the thermostat or limit control.

When power is supplied to valve terminals 3 and 4, the

pilot valve opens to the preset position. When power is sup-

plied to terminals 1 and 2, the main valve opens to its preset

position.

The regular factory setting is stamped on the valve body

(3.5 in. wg).

To adjust regulator:

1. Set thermostat at setting for no call for heat.

2. Turn main gas valve to OFF position.

3. Remove

⁄

-in. pipe plug from manifold. Install a water

manometer pressure-measuring device.

4. Set main gas valve to ON position.

5. Set thermostat at setting to call for heat.

6. Remove screw cap covering regulator adjustment screw

(See Fig. 54).

7. Turn adjustment screw clockwise to increase pressure or

counterclockwise to decrease pressure.

8. Once desired pressure is established, set thermostat set-

ting for no call for heat, turn off main gas valve, remove

pressure-measuring device and replace

⁄

-in. pipe plug

and screw cap.

Fig. 49 — Evaporator-Fan Alignment and

Adjustment

Main Burners — For all applications, main burners are

factory set and should require no adjustment.

MAIN BURNER REMOVAL (Fig. 55)

1. Shut off (ﬁeld-supplied) manual main gas valve.

2. Shut off power to unit.

3. Remove heating access panel.

4. Disconnect gas piping from gas valve inlet.

5. Remove wires from gas valve.

6. Remove wires from rollout switch.

7. Remove sensor wire and ignitor cable from IGC board.

8. Remove 2 screws securing manifold bracket to basepan.

9. Remove 4 screws that hold the burner support plate flange

to the vestibule plate.

10. Lift burner assembly out of unit.

11. Reverse procedure to re-install burners.

Filter Drier — Replace whenever refrigerant system is

exposed to atmosphere.

Protective Devices

COMPRESSOR PROTECTION

Overcurrent — Each compressor has one manual reset, cali-

brated trip, magnetic circuit breaker. Do not bypass connec-

tions or increase the size of the circuit breaker to correct trouble.

Determine the cause and correct it before resetting the breaker.

Overtemperature — Each 06D type compressor (024-038 units)

has an internal protector to protect it against excessively high

discharge gas temperatures.

Fig. 50 — Belt Tension Adjustment

Fig. 51 — Condenser-Fan Adjustment

Fig. 52 — Cooling Charging Chart,

48EJ,EK,EW,EY024-034

Fig. 53 — Cooling Charging Chart,

48EJ,EK,EW,EY038-048

Crankcase Heater — Each compressor has a crankcase heater

to prevent absorption of liquid refrigerant by oil in the crank-

case when the compressor is idle. Since power for the crank-

case heaters is drawn from the unit incoming power, main

unit power must be on for the heaters to be energized.

IMPORTANT: After a prolonged shutdown or serv-

ice job, energize the crankcase heaters for 24 hours

before starting the compressors.

EVAPORATOR FAN MOTOR PROTECTION —A manual

reset, calibrated trip, magnetic circuit breaker protects against

overcurrent. Do not bypass connections or increase the size

of the breaker to correct trouble. Determine the cause and

correct it before resetting the breaker. If the evaporator-fan

motor is replaced with a different horsepower motor, resiz-

ing of the circuit breaker is required. Contact Carrier

Application Engineering.

CONDENSER-FAN MOTOR PROTECTION — Each

condenser-fan motor is internally protected against

overtemperature.

HIGH- AND LOW-PRESSURE SWITCHES — If either

switch trips, or if the compressor overtemperature switch ac-

tivates, that refrigerant circuit will be automatically stopped.

See Compressor Lockout Logic section on this page.

FREEZE PROTECTION THERMOSTAT (FPT) — Freeze

protection thermostats are located on the evaporator coil for

each circuit. One is located at the top and bottom of each

circuit. It detects frost build-up and turns off the compressor,

allowing the coil to clear. Once the frost has melted, the com-

pressor can be reenergized.

Relief Devices — All units have relief devices to pro-

tect against damage from excessive pressures (i.e., ﬁre). These

devices are installed on the suction line, liquid line, and on

the compressor.

Power Circuit — A typical power wiring schematic is

shown in Fig. 56.

Control Circuit, 115-V — This control circuit is pro-

tected against overcurrent by a 5.0 amp circuit breaker (CB3).

Breaker can be reset. If it trips, determine cause of trouble

before resetting. A typical 115-v control wiring schematic is

shown in Fig. 57 and 58.

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

tected against overcurrent by a 3.2 amp circuit breaker (CB4).

Breaker can be reset. If it trips, determine cause of trouble

before resetting. A typical 24-v control wiring schematic is

shown in Fig. 59 and 60.

Compressor Lockout Logic — If any of the safe-

ties trip, the circuit will automatically reset (providing the

safety has reset) and restart the compressor in 15 minutes. If

any of the safeties trip 3 times within a 90-minute period,

then the circuit will be locked out and will require manual

resetting by turning off either the unit disconnect or the con-

trol circuit breaker, or opening the thermostat.

Replacement Parts — A complete list of replacement

parts may be obtained from any Carrier distributor upon

request.

Fig. 54 — Gas Valve

Fig. 55 — Main Burner Removal

LEGEND and NOTES for Fig. 56-60 — Typical Wiring Schematics

AHA — Adjustable Heat Anticipator

BP — Building Pressure

BR — Burner Relay

C—Contactor, Compressor

CAP — Capacitor

CB — Circuit Breaker

CC — Cooling Compensator

CCB — Controller Circuit Breaker

CCH — Crankcase Heater

COM — Communication

COMP — Compressor Motor

CR — Control Relay

DM — Damper Motor

DP — Duct Pressure

EC — Enthalpy Control

EQUIP — Equipment

FLA — Full Load Amps

FPT — Freeze Protection Thermostat

FU — Fuse

GRD — Ground

GVR — Gas Valve Relay

HPS — High-Pressure Switch

HS — Hall Effect Sensor

HV — High Voltage

IDM — Induced-Draft Motor

IFC — Indoor Fan Contactor

IFCB — Indoor Fan Circuit Breaker

IFM — Indoor-Fan Motor

IFR — Indoor-Fan Relay

IGC — Integrated Gas Unit Controller

IP — Internal Protector

L—Light

LPS — Low-Pressure Switch

MGV — Main Gas Valve

NC — Normally Closed

NO — Normally Open

OAT — Outdoor-Air Thermistor

OFC — Outdoor-Fan Contactor

OFM — Outdoor-Fan Motor

PEC — Power Exhaust Contactor

PEM — Power Exhaust Motor

PES — Power Exhaust Sequencer

PESC — Power Exhaust Sequencer

Controller

PL — Plug Assembly

R—Relay

RAT — Return-Air Thermistor

RS — Rollout Switch

SAT — Supply-Air Thermistor

TB — Terminal Block

TC — Thermostat Cooling

TH — Thermostat Heating

TRAN — Transformer

UL — Compressor Unloader

VFD — Variable Frequency Drive

Terminal (Marked)

Terminal (Unmarked)

Terminal Block

Splice

Factory Wiring

Field Wiring

To Indicate Common Potential Only,

Not To Represent Wiring

NOTES:

1. Connect TRAN1 to H4 for 460 v units. Connect to H3 for 230 v. If

208/230 v units are run with a 208 v power supply connect to H2.

2. Connect TRAN2 to black lead for 460 v units. Connect to orange

lead for 230 v units. If 208/230 v units are run with a 208 v power

supply connect to red lead.

3. Circuit breaker must trip amps are equal to or less than 156% FLA

for CB1 and CB2. All others are 140%.

4. If any of the original wire furnished must be replaced, it must be

replaced with type 90 C wire or its equivalent.

5. Compressors and/or fan motors are thermally protected.

6. Three phase motors are protected against primary single phasing

conditions.

7. Red wire and violet wire are spliced together at the factory. The

brown wire has a wire nut added at the factory.

TABLE A

THE FOLLOWING COMPRESSORS HAVE

TWO PARALLEL WIRES RUN FROM TB1

TO THE COMPRESSORS

(NOT SHOWN ON LABEL DIAGRAM)

COMPRESSOR

MODEL VOLTAGE WIRE

QUANTITY

06D-537 208/230-3-60 2

LEGEND

TABLE B

THE FOLLOWING FAN MOTORS HAVE TWO

PARALLEL WIRES RUN FROM TB1 TO THE

FAN MOTORS

(NOT SHOWN ON LABEL DIAGRAM)

INDOOR

MOTOR VOLTAGE WIRE

QUANTITY

20 HP 208/230-3-60 2

Fig. 56 — Typical Power Schematic; 48EJ,EK,EW,EY024-034; 208/230-3-60 and 460-3-60

Fig. 57 — Typical VAV 115-v Control Circuit

Fig. 58 — Typical CV 115-v Control Circuit

Fig. 59 — Typical VAV 24-v Control Circuit

Fig. 60 — Typical CV 24-v Control Circuit

TROUBLESHOOTING

Typical refrigerant circuiting diagrams are shown in Fig. 61-63. An algorithm diagram of the IGC (Integrated Gas Unit Con-

troller) control is shown in Fig. 64.

LEGEND

FPS — Freeze Protection Switch

HPS — High-Pressure Switch

LPS — Low-Pressure Switch

Fig. 61 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY024-034)

LEGEND

FPS — Freeze Protection Switch

HPS — High-Pressure Switch

LPS — Low-Pressure Switch

Fig. 62 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY038,044)

LEGEND

FPS — Freeze Protection Switch

HPS — High-Pressure Switch

LPS — Low-Pressure Switch

Fig. 63 — Typical Refrigerant Circuiting (48EJ,EK,EW,EY048)

NOTE: Thermostat Fan Switch in the ‘‘AUTO’’ position or sensor-equipped unit.

Fig. 64 — IGC Control (Heating and Cooling)

LEGEND

IDM — Induced-Draft Motor

IGC — Integrated Gas Unit Controller

The alarm codes for the IGC control board are shown in

Table 22.

Table 22 — IGC Control Board LED Alarms

INDICATION ERROR MODE

ON Normal Operation

OFF Hardware Failure

1 FLASH Fan ON/OFF Delay Modiﬁed

2 FLASHES Limit Switch Fault

3 FLASHES Flame Sense Fault

4 FLASHES 4 Consecutive Limit Switch Faults

5 FLASHES Ignition Lockout Fault

6 FLASHES Induced Draft Motor Fault

7 FLASHES Rollout Switch Fault

8 FLASHES Internal Control Fault

Diagnostic LEDs — There are 3 LEDs (red, yellow,

and green) on the lower right hand side of the control board.

The red light is used to check unit operation and alarms. A

constant pulse is normal unit operation. A series of quick

blinks indicates an alarm. Refer to Table 23 below for a de-

scription of alarms. The yellow LED blinks during transmis-

sion with the CCN (Carrier Comfort Network). The green

LED blinks during transmission with the expansion board.

Table 23 — Control Board LED Alarms

LED Blinks Error Code Description Troubleshooting Comments

1— Normal Operation The expansion board and control board ﬂash the red LED in one-second

intervals when the board is operating properly.

2HF-13 Compressor 1 Safety

The high or low pressure safety switch for compressor no. 1 has opened for

3 seconds. The error will be cleared and compressor no. 1 will be allowed

to turn on in 15 minutes. If the safeties have been tripped 3 times in 90 min-

utes, compressor no. 1 will be locked out until the control board has been

manually reset.

3HF-14 Compressor 2 Safety

The high or low pressure safety switch for compressor no. 2 has opened for

3 seconds. The error will be cleared and compressor no. 2 will be allowed

to turn on in 15 minutes. If the safeties have been tripped 3 times in 90 min-

utes, compressor no. 2 will be locked out until the control board has been

manually reset.

4HF-15 Thermostat Failure 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.

5HF-05 SAT Thermistor Failure The supply-air temperature (SAT) sensor has failed. First check for wiring

errors, then replace sensor.

6HF-06 OAT Thermistor Failure The outside air temperature (OAT) sensor has failed. First check for wiring

errors, then replace sensor.

7HF-03 Space Temp. Sen. Failure The space temperature sensor has failed. First check for wiring errors, then

replace sensor.

8HF-12 RAT Thermistor Failure 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.

9SE-05 Loss of Communications

with Expansion Board

Communications between the expansion board and the control board have

been interrupted. Ensure that an expansion board is installed and wired us-

ing the wire harness supplied with the expansion module. If an expansion

board is not used ensure that DIP switch position 3 is in the closed position,

and reset power.

10 HF-16 Control Board Failure Generated when hardware has failed on control board. Replace the control

board.

11 HF-17 Expansion Board Failure Generated when hardware has failed on the expansion board. Replace the

expansion board.

DIP — Dual In-Line Package

VAV — Variable Air Volume

Tables 24-26 show the input and output channel

designations.

Table 24 — I/O Channel Designations Base Module — CV

TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT

T1-2 SPT (CCN) — 10KVThermistor T23-25 Compressor 2 Safety — DI (24 vac)

T3-4 STO (CCN) — 10KVThermistor T24-25 Outside Air Enthalpy — DI (24 vac)

T5-6 OAT — 5KVThermistor T26-27 Economizer Pos. — AO (4-20 mA)

T7-8 SAT — 5KVThermistor T28-29 Heat 1 Relay — DO (24 vac)

T9-10 —T30-29 Heat 2 Relay — DO (24 vac)

T11-12 SAT Reset — AI (4 to 20 mA) T31-32 CV Power Exhaust 1/Modulating Power Exhaust — DO (115 vac)

T13-14 —T33-32 CV Power Exhaust2—DO(115vac)

T15-16 —T34-35 Condenser Fan — DO (115 vac)

T17-25 Y1 or Remote Start/Stop — DI (24 vac) T36-35 OFC2 — DO (115 vac)

T18-25 Y2 — DI (24 vac) T37-38 —

T19-25 W1 — DI (24 vac) T39-38 —

T20-25 W2 — DI (24 vac) K1 Indoor Fan Relay — DO (LV)

T21-25 G — DI (24 vac) K2 Compr.1—DO(HV)

T22-25 Compressor 1 Safety — DI (24 vac) K3 Compr.2—DO(HV)

Table 25 — I/O Channel Designations Base Module — VAV

TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT

T1-2 SPT (CCN) — 10KVThermistor T23-25 Compressor 2 Safety — DI (24 vac)

T3-4 RAT — 5KVThermistor T24-25 Outside Air Enthalpy — DI (24 vac)

T5-6 OAT — 5KVThermistor T26-27 Economizer Pos. — AO (4-20 mA)

T7-8 SAT — 5KVThermistor T28-29 Heat 1 Relay − DO (24 vac)

T9-10 —T30-29 Heat Interlock Relay — DO (24 vac)

T11-12 SAT Reset — AI (4 to 20 mA) T31-32 Modulated Power Exhaust — DO (115 vac)

T13-14 —T33-32 —

T15-16 —T34-35 Condenser Fan — DO (115 vac)

T17-25 Remote Start/Stop — DI (24 vac) T36-35 OFC2 — DO (115 vac)

T18-25 —T37-38 Unloader1—DO(115vac)

T19-25 —T39-38 Unloader2—DO(115vac)

T20-25 —K1 Indoor Fan Relay — DO (LV)

T21-25 —K2 Compr. 1 (HV)

T22-25 Compressor 1 Safety — DI (24 vac) K3 Compr.2—DO(HV)

Table 26 — I/O Channel Designations Expansion Module (Field-Installed) — CV and VAV

TERMINAL NO. ASSIGNMENT TERMINAL NO. ASSIGNMENT

T1-2 —T23-25 Fire — Evacuation — DI (24 vac)

T3-4 —T24-25 Fire — Smoke Purge — DI (24 vac)

T5-6 —T26-27 —

T7-8 —T28-29 —

T9-10 —T30-29 Alarm Light Indicator — DO (24 vac)

T11-12 IAQ Indoor — AI (4 to 20 mA) T31-32 Power Exhaust Fire No.1—DO(115vac)

T13-14 IAQ Outdoor — AI (4 to 20 mA) T33-32 Power Exhaust Fire No.2—DO(115vac)

T15-16 —T34-35 Power Exhaust Fire No.3—DO(115vac)

T17-25 Fan Status — DI (24 vac) T36-35 Power Exhaust Fire No.4—DO(115vac)

T18-25 Filter Status − DI (24 vac) T37-38 —

T19-25 Field Applied Status — DI (24 vac) T39-38 —

T20-25 Demand Limit — DI (24 vac) K1 —

T21-25 Fire — Unit Shutdown — DI (24 vac) K2 —

T22-25 Fire — Pressurization — DI (24 vac) K3 —

LEGEND (Tables 24-26)

AI — Analog Input

AO — Analog Output

CCN — Carrier Comfort Network

CV — Constant Volume

DI — Direct Input

DO — Direct Output

HV — High Voltage

IAQ — Indoor Air Quality

KV—Kilo-Ohms

LV — Low Voltage

OAT — Outdoor-Air Temperature

OFC — Outdoor Fan Contactor

RAT — Return-Air Temperature

SAT — Supply-Air Temperature

SPT — Space Temperature

STO — Space Temperature Offset

T—Terminal

VAV — Variable Air Volume

NOTE: For 4 to 20 mA signals, all even numbered terminals are negative (−) polarity, and all odd numbered terminals are positive (+) polarity.

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 • Maintenance

• Installation Overview • 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.

Manufacturer reserves the right to discontinue, or change at any time, speciﬁcations or designs without notice and without incurring obligations.

Book 1

Tab 1a

PC 111 Catalog No. 564-962 Printed in U.S.A. Form 48E-5SI Pg 62 8-97 Replaces: 48E-3SI

START-UP CHECKLIST

MODEL NO.:

SOFTWARE VERSION (SEE FIG. 16)

DATE:

SERIAL NO.:

TECHNICIAN:

PRE-START-UP:

MVERIFY THAT DIP SWITCH SETTINGS ARE CORRECT

MVERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT

MREMOVE ALL SHIPPING HOLDDOWN BOLTS AND BRACKETS PER INSTRUCTIONS

MVERIFY INSTALLATION OF ECONOMIZER HOOD

MVERIFY INSTALLATION OF ALL OPTIONS AND ACCESSORIES

MVERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS

MVERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT

MCHECK GAS PIPING FOR LEAKS

MCHECK THAT INDOOR-AIR FILTERS ARE CLEAN AND IN PLACE

MVERIFY THAT UNIT IS LEVEL WITHIN TOLERANCES

MCHECK FAN WHEELS AND PROPELLERS FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SETSCREW

IS TIGHT

MVERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED

MVERIFY THAT SUCTION, DISCHARGE, AND LIQUID SERVICE VALVES ON EACH CIRCUIT ARE OPEN

START-UP

ELECTRICAL

SUPPLY VOLTAGE L1-L2 L2-L3 L3-L1

COMPRESSOR AMPS — COMPRESSOR NO. 1 L1 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.

MADJUST VARIABLE FREQUENCY DRIVE (VFD) TO APPLICATION REQUIREMENTS.

TEMPERATURES

OUTDOOR-AIR TEMPERATURE F DB (Dry Bulb)

RETURN-AIR TEMPERATURE FDB F WB (Wet Bulb)

COOLING SUPPLY AIR F

GAS HEAT SUPPLY AIR F

PRESSURES

GAS INLET PRESSURE IN. WG

GAS MANIFOLD PRESSURE STAGE NO. 1 IN. WG STAGE NO. 2 IN. WG

REFRIGERANT SUCTION CIRCUIT NO. 1 PSIG CIRCUIT NO. 2 PSIG

REFRIGERANT DISCHARGE CIRCUIT NO. 1 PSIG CIRCUIT NO. 2 PSIG

MVERIFY REFRIGERANT CHARGE USING CHARGING CHARTS ON PAGE 48

CL-1

GENERAL

MSET ECONOMIZER MINIMUM VENT POSITION TO JOB REQUIREMENTS

MENSURE 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.

ADDITIONAL NOTES:

_______________________________________________________________________________________________________

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

CUT ALONG DOTTED LINE CUT ALONG DOTTED LINE

Manufacturer reserves the right to discontinue, or change at any time, speciﬁcations or designs without notice and without incurring obligations.

Book 1

Tab 1a

PC 111 Catalog No. 564-962 Printed in U.S.A. Form 48E-5SI Pg CL-2 8-97 Replaces: 48E-3SI

Carrier Single Package Rooftop Units Electric Cooling Gas Heating 48Ej Users Manual

48EJ to the manual b9a43d94-fd73-49a9-aa7f-83f77933caab

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