Carrier 48GS 018-060, 024-040, 030-040, 030-060, 036-060, 036-090, 042-060, 042-090, 048-090, 048-115, 048-130, 060-090, 060-115, 060-130, 48GX 024-060, 042-060, 042-090, 048-090, 048-115, 048-130, 060-090 Installation, Start-Up and Service Instructions

48GS018-060

48GX024-060

Single Package Gas Heating/

Electric Cooling Units

Installation, Start-Up and

Service Instructions

CONTENTS

Page

SAFETY CONSIDERATIONS

. . . . . . . . . . . . . . . . . 1-3

General

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

RECEIVING AND INSTALLATION

. . . . . . . . . . . . 4-14

Step 1 — Check Equipment

. . . . . . . . . . . . . . . . .

4

• IDENTIFY UNIT

• INSPECT SHIPMENT

Step 2 — Provide Unit Support

. . . . . . . . . . . . . .

4

• ROOF CURB

• SLAB MOUNT

• GROUND MOUNT

Step 3 — Field Fabricate Ductwork

. . . . . . . . . .

4

Step 4 — Provide Clearances

. . . . . . . . . . . . . . .

4

Step 5 — Rig and Place Unit

. . . . . . . . . . . . . . . .

4

Step 6 — Connect Condensate Drain

. . . . . . . .

7

Step 7 — Install Flue Hood

. . . . . . . . . . . . . . . . . .

7

Step 8 — Install Gas Piping

. . . . . . . . . . . . . . . . .

7

Step 9 — Install Duct Connections

. . . . . . . . . . 10

• CONFIGURING UNITS FOR DOWNFLOW

(VERTICAL) DISCHARGE

Step 10 — Install Electrical Connections

. . . . 11

• HIGH-VOLTAGE CONNECTIONS

• SPECIAL PROCEDURES FOR 208-V

OPERATION

• CONTROL VOLTAGE CONNECTIONS

• HEAT ANTICIPATOR SETTING

• TRANSFORMER PROTECTION

PRE-START-UP

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 14,15

START-UP

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15-29

MAINTENANCE

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 29-32

TROUBLESHOOTING

. . . . . . . . . . . . . . . . . . . . . . 33,34

START-UP CHECKLIST

. . . . . . . . . . . . . . . . . . . . . CL-1

NOTE TO INSTALLER — Before the installation, READ

THESE INSTRUCTIONS CAREFULLY AND COM-

PLETELY. Also, make sure the User’s Manual and Replacement Guide are left with the unit after installation. The furnace is NOT to be used for temporary heating of buildings or structures under construction.

Fig. 1 — Unit 48GS and 48GX

(Shown with Accessory Wire Grille)

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

Use quenching cloth for unbrazing operations. Have fire extinguisher available for all brazing operations.

Improper installation, adjustment, alteration, service, maintenance, or use can cause carbon monoxide poisoning, fire, or an explosion which can result in personal injury or unit damage. Consult a qualified installer, service agency, or gas supplier for information or assistance. The qualified installer or agency must use only factory-authorized kits or accessories when modifying this product.

Before performing service or maintenance operations on unit, turn off gas supply then unit main power switch.

Electrical shock could cause personal injury.

SAFETY CONSIDERATIONS

Installation and servicing of air-conditioning equipment can be hazardous due to system pressure and electrical components. Only trained and qualified personnel should install, repair, or service air-conditioning equipment.

Untrained personnel can perform basic maintenance functions of cleaning coils and filters. All other operations should be performed by trained service personnel. When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached to the unit, and other safety precautions that may apply.

General —

The 48GS,GX units (see Fig. 1) are fully selfcontained, combination Category I gas heating/electric cooling units designed for outdoor installation. See Fig. 2 and 3 (pages 2 and 3) for unit dimensions. All unit sizes have return and discharge openings for both horizontal and downflow configurations, and are factory shipped with all downflow duct openings covered. Units may be installed either on a rooftop, a cement slab, or directly on the ground (if permitted by local codes). See Fig. 4 for roof curb dimensions.

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

Book 1 4

Tab 1a 6a

PC 111 Catalog No. 534-732 Printed in U.S.A.

Form 48GS,GX-1SI Pg 1 1-99 Replaces: 48GS-1SI

REQ’D CLEARANCES FOR OPERATION AND SERVICING. in. (mm)

Evaporator coil access side . . . . . . . . . . . . . . . . . . 36 (914)

Power entry side (except for NEC requirements) . . . . . . . . . 36 (914)

Unit top . . . . . . . . . . . . . . . . . . . . . . . . . . 48 (1219)

Side opposite ducts . . . . . . . . . . . . . . . . . . . . . 36 (914)

Duct panel . . . . . . . . . . . . . . . . . . . . . . . . 12 (304.8)*

*Minimum distances: If unit is placed less than 12 in. (304.8 mm) from wall system, then the system performance may be compromised.

UNIT

48GS018040

48GS024040/060

48GS030040/060

48GS036060/090

48GS042060/090

48GX024040/060

48GX030040/060

48GX036060/090

ELECTRICAL

CHARACTERISTICS

208/230-1-60

208/230-1-60

208/230-1-60, 208/230-3-60

208/230-1-60, 208/230-3-60, 460-3-60

208/230-1-60, 208/230-3-60, 460-3-60

208/230-1-60

208/230-1-60, 208/230-3-60

208/230-1-60, 208/230-3-60, 460-3-60

UNIT WEIGHT lb

249.0

280.0

280.0

314.0

355.0

290.0

313.0

321.0

kg

113.2

127.3

127.3

142.7

161.4

639.3

690.0

707.7

REQ’D CLEARANCES TO COMBUSTIBLE MAT’L. in. (mm)

Top of unit . . . . . . . . . . . . . . . . . . . . . . . . . 14 (355.6)

Duct side of unit . . . . . . . . . . . . . . . . . . . . . . . 2 (50.8)

Side opposite ducts . . . . . . . . . . . . . . . . . . . . . 14 (355.6)

Bottom of unit . . . . . . . . . . . . . . . . . . . . . . . 0.50 (12.7)

Flue panel . . . . . . . . . . . . . . . . . . . . . . . . . 36 (914.4)

NEC REQ’D CLEARANCES. in. (mm)

Between units, power entry side . . . . . . . . . . . . . . 42 (1066.8)

Unit and ungrounded surfaces, power entry side . . . . . . . . . 36 (914)

Unit and block or concrete walls and other grounded surfaces, control box side . . . . . . . . . . . . . . . . . 42 (1066.8)

UNIT HEIGHT in. [mm]

‘‘A’’

35.02 [889.5]

35.02 [889.5]

35.02 [889.5]

35.02 [889.5]

35.02 [889.5]

35.02 [889.5]

39.02 [991.1]

35.02 [889.5]

X

20.0 [508.0]

CENTER OF GRAVITY in. [mm]

Y

14.0 [355.6]

Z

15.0 [381.0]

22.5 [571.5]

21.5 [546.1]

22.5 [571.5]

21.5 [546.1]

22.0 [558.8]

22.0 [558.8]

22.0 [558.8]

13.0 [330.2]

13.75 [349.3]

14.0 [355.6]

13.5 [342.9]

14.5 [368.3]

15.3 [387.4]

15.3 [387.4]

15.0 [381.0]

15.0 [381.0]

13.0 [330.2]

13.0 [330.2]

16.0 [406.4]

17.6 [447.0]

16.5 [419.1]

LEGEND

CG

— Center of Gravity

COND

— Condenser

EVAP

— Evaporator

NEC

— National Electrical Code

REQ’D — Required

NOTE: Dimensions are in mm [in.]

Fig. 2 — 48GS018-042 and 48GX024-036 Unit Dimensions

2

REQ’D CLEARANCES FOR OPERATION AND SERVICING. in. (mm)

Evaporator coil access side . . . . . . . . . . . . . . . . . . 36 (914)

Power entry side (except for NEC requirements) . . . . . . . . . 36 (914)

Unit top . . . . . . . . . . . . . . . . . . . . . . . . . . 48 (1219)

Side opposite ducts . . . . . . . . . . . . . . . . . . . . . 36 (914)

Duct panel . . . . . . . . . . . . . . . . . . . . . . . . 12 (304.8)*

*Minimum distances: If unit is placed less than 12 in. (304.8 mm) from wall system, then the system performance may be compromised.

LEGEND

CG

— Center of Gravity

COND

— Condenser

EVAP

— Evaporator

NEC

— National Electrical Code

REQ’D — Required

NOTE: Dimensions are in mm [in.]

REQ’D CLEARANCES TO COMBUSTIBLE MAT’L. in. (mm)

Top of unit . . . . . . . . . . . . . . . . . . . . . . . . . 14 (355.6)

Duct side of unit . . . . . . . . . . . . . . . . . . . . . . . 2 (50.8)

Side opposite ducts . . . . . . . . . . . . . . . . . . . . . 14 (355.6)

Bottom of unit . . . . . . . . . . . . . . . . . . . . . . . 0.50 (12.7)

Flue panel . . . . . . . . . . . . . . . . . . . . . . . . . 36 (914.4)

NEC REQ’D CLEARANCES. in. (mm)

Between units, power entry side . . . . . . . . . . . . . . 42 (1066.8)

Unit and ungrounded surfaces, power entry side . . . . . . . . . 36 (914)

Unit and block or concrete walls and other grounded surfaces, control box side . . . . . . . . . . . . . . . . . 42 (1066.8)

FLUE HOOD

UNIT

48GS048090/115/130

48GS060090/115/130

48GX042060/090

48GX048090/115/130

48GX060090/115/130

ELECTRICAL

CHARACTERISTICS

208-230/1/60, 208/230-3-60, 460-3-60

208/230-1-60, 208/230-3-60, 460-3-60

208/230-1-60, 208/230-3-60, 460-3-60

208/230-1-60, 208/230-3-60, 460-3-60

208/230-1-60, 208/230-3-60, 460-3-60

UNIT WEIGHT lb

415

450

382

421

468

kg

188.6

204.5

842.2

928.2

1031.7

UNIT HEIGHT in. [mm]

‘‘A’’

38.98 [ 990.2]

38.98 [ 990.2]

38.98 [ 990.2]

38.98 [ 990.2]

42.98 [1091.7]

X

22 [558.5]

CENTER OF GRAVITY in. [mm]

16

Y

[406.4]

Z

17 [432.0]

22 [558.5]

23.0 [584.2]

21.5 [546.1]

23.5 [596.9]

16 [406.4]

16.3 [412.8]

16.6 [422.1]

16.3 [412.8]

17 [432.0]

16.6 [421.6]

18.0 [457.2]

17.6 [447.0]

Fig. 3 — 48GS048,060 and 48GX042-060 Unit Dimensions

3

RECEIVING AND INSTALLATION

Step 1 — Check Equipment

IDENTIFY UNIT — The unit model number and serial number are stamped on unit identification plate. Check this information against shipping papers and job data.

INSPECT SHIPMENT — Inspect for shipping damage while unit is still on shipping pallet. If unit appears to be damaged or is torn loose from its anchorage, have it examined by transportation inspectors before removal. Forward claim papers directly to transportation company. Manufacturer is not responsible for any damage incurred in transit.

Check all items against shipping list. Immediately notify the nearest Carrier Air Conditioning office if any item is missing.

To prevent loss or damage, leave all parts in original packages until installation.

Step 2 — Provide Unit Support

ROOF CURB — Install accessory roof curb in accordance with instructions shipped with curb. See Fig. 4 for roof curb dimensions. Install insulation, cant strips, roofing, and flashing. Ductwork must be attached to curb.

IMPORTANT: The gasketing of the unit to the roof curb is critical for a watertight seal. Install gasketing material supplied with the roof curb. Improperly applied gasketing can also result in air leaks and poor unit performance.

Curb should be level to within 1 ⁄

4 inch. This is necessary for unit drain to function properly. Refer to accessory roof curb installation instructions for additional information as required.

SLAB MOUNT — Place the unit on a solid, level concrete pad that is a minimum of 4 in. thick with 2 in. above grade.

The slab should be flush on the compressor end of the unit

(to allow condensate drain installation) and should extend

2 in. on the three remaining sides of the unit. See Fig. 5. Do not secure the unit to the slab except when required by local codes.

GROUND MOUNT — The unit may be installed either on a slab or placed directly on the ground if local codes permit.

Place the unit on level ground prepared with gravel for condensate discharge.

Step 3 — Field Fabricate Ductwork —

Secure all ducts to roof curb and building structure on vertical discharge units. Do not connect ductwork to unit. For horizontal applications, unit is provided with flanges on the horizontal openings. All ductwork should be secured to the flanges.

Insulate and weatherproof all external ductwork, joints, and roof openings with counter flashing and mastic in accordance with applicable codes.

Ducts passing through an unconditioned space must be insulated and covered with a vapor barrier.

If a plenum return is used on a vertical unit, the return should be ducted through the roof deck to comply with applicable fire codes.

A minimum clearance is not required around ductwork.

Cabinet return-air static shall not exceed −.25 in. wg.

Step 4 — Provide Clearances —

The required minimum operating and service clearances are shown in

Fig. 2 and 3. Adequate combustion, ventilation, and condenser air must be provided, in accordance with section 5.3,

Air for Combustion and Ventilation, of the National Fuel Gas

Code ANSI (American National Standards Institute) Z223.1

(in Canada, sections 7.2, 7.3 or 7.4 or Can/CGA [Canadian

Gas Association] B149 Installation Codes), or applicable provisions of local building code.

Do not restrict condenser airflow. An air restriction at either the outdoor-air inlet or the fan discharge can be detrimental to compressor life.

The condenser pulls air through the condenser coil and discharges it through the top cover. Be sure that the fan discharge does not recirculate to the condenser coil. Do not locate the unit in either a corner or under an overhead obstruction. The minimum clearance under a partial overhang (such as a normal house overhang) is 48-in. above the unit top.

The maximum horizontal extension of a partial overhang must not exceed 48 inches.

Do not place the unit where water, ice, or snow from an overhang or roof will damage or flood the unit. Do not install the unit on carpeting, tile, or other combustible materials. The unit may be installed on wood flooring or on

Class A, B, or C roof covering materials.

Step 5 — Rig and Place Unit

When installing the unit on a rooftop, be sure the roof will support the additional weight.

Use spreader bars or crate top when rigging the unit. The units must be rigged for lifting as shown in Fig. 6. Refer to

Table 1 and 2 for operating weight. Use extreme caution to

prevent damage when moving the unit. Unit must remain in an upright position during all rigging and moving opera-

tions. The unit must be level for proper condensate drainage; therefore, the ground-level pad or accessory roof curb must be level before setting the unit in place. When a fieldfabricated support is used, be sure that the support is level and properly supports the unit.

4

FLAT

CURB

UNIT SIZE

48GS018-042

48GX024-036

48GS048,060

48GX042-060

PART NUMBER

CPRFCURB006A00

CPRFCURB007A00

CPRFCURB008A00

CPRFCURB009A00

NOTES:

1. Roof curb must be set up for unit being installed.

2. Seal strip must be applied as required to unit being installed.

3. Dimensions in [ ] are in millimeters.

4. Roof curb is made of 16 gage steel.

5. Table lists only the dimensions per part number that have changed.

6. Attach ductwork to curb (flanges of duct rest on curb).

7. Insulated panels: 1-in. thick fiberglass 1 lb density.

8. Dimensions are in inches.

A in. [mm]

8 [203]

14 [356]

8 [203]

14 [356]

B in. [mm]

11 27 ⁄

32

[301]

11 27 ⁄

32

[301]

15 27 ⁄

32

[402]

15 27 ⁄

32

[402]

C in. [mm]

30 5 ⁄

8

[778]

30 5 ⁄

8

[778]

42 1 ⁄

8

[1070]

42 1 ⁄

8

[1070]

D in. [mm]

28 3 ⁄

4

[730]

28 3 ⁄

4

[730]

40 1 ⁄

4

[1022]

40 1 ⁄

4

[1022]

SIDE PANEL

0.75"

3.0"

BASE PAN

BOTTOM SUPPLY

4.0"

SUPPORT RIB(S)

SEAL STRIP

(FACTORY SUPPLIED)

COUNTER FLASHING

(FIELD SUPPLIED)

ROOFING FELT

(FIELD SUPPLIED)

CANT STRIP

(FIELD SUPPLIED)

NAILER

INSULATION

(FIELD SUPPLIED)

ROOFING MATERIAL

(FIELD SUPPLIED)

FULL PERIMETER CURB

Fig. 4 — Roof Curb Dimensions

5

Fig. 5 — Slab Mounting Details

UNIT 48GS

Size

018

024

030

036

042

048

060

UNIT 48GX

Size

024

030

036

042

048

060 lb

271

MAXIMUM

WEIGHT kg

123.2

302

302

336

137.3

137.3

152.7

377

437

472

171.4

198.6

214.5

in.

20.0

22.5

21.5

22.5

21.5

22.0

22.0

A mm

508.0

571.5

546.1

571.5

546.1

558.5

558.5

lb

312

335

MAXIMUM

WEIGHT kg

688.0

738.7

343

404

443

490

756.4

890.9

976.9

1080.5

in.

22.0

22.0

22.0

23.0

21.5

23.5

A mm

558.5

558.5

558.5

584.2

546.1

596.9

Fig. 6 — Suggested Rigging in.

14.0

13.0

13.75

14.0

13.5

17.0

17.0

B mm

355.6

330.2

349.3

355.6

342.9

432.0

432.0

in.

14.5

15.3

15.3

16.3

16.3

16.3

B mm

368.3

388.6

388.6

414.0

414.0

414.3

6

Step 6 — Connect Condensate Drain

NOTE: When installing condensate drain connection be sure to comply with local codes and restrictions.

Models 48GS and GX dispose of condensate water through a

3

⁄

4 in. NPT fitting which exits through the compressor access panel. See Fig. 2 and 3 for location.

Condensate water can be drained directly onto the roof in rooftop installations (where permitted) or onto a gravel apron in ground-level installations. Install a field-supplied condensate trap at end of condensate connection to ensure proper drainage. Make sure that the outlet of the trap is at least

1 in. lower than the drain-pan condensate connection to prevent the pan from overflowing. See Fig. 7. Prime the trap with water. When using a gravel apron, make sure it slopes away from the unit.

If the installation requires draining the condensate water away from the unit, install a 2-in. trap at the condensate connection to ensure proper drainage. See Fig. 7. Make sure that the outlet of the trap is at least 1 in. lower than the drain-pan condensate connection to prevent the pan from overflowing.

Prime the trap with water. Connect a drain tube using a minimum of 3 ⁄

4

-in. PVC or 3 ⁄

4

-in. copper pipe (all field-supplied) at the outlet end of the 2-in. trap. Do not undersize the tube.

Pitch the drain tube downward at a slope of at least one in.

for every 10 ft of horizontal run. Be sure to check the drain tube for leaks.

Fig. 7 — Condensate Trap

Step 7 — Install Flue Hood —

The flue hood assembly is shipped screwed to the coil panel in the indoor blower compartment. Remove the service access panel to locate the assembly.

For units being installed in California Air Quality

Management Districts which require NO x be field installed.

emissions of

40 nanograms/joule or less, a field-installed low NO x kit must

For 40,000 and 60,000 Btuh input models, use kit part number CPLOWNOX002A00. This kit contains two NO x reduction baffles and one conversion label. For 90,000, 115,000 and 130,000 Btuh input models, use kit part number

CPLOWNOX003A00. This kit contains three NO tion baffles and one conversion label.

x reduc-

The venting system is designed to ensure proper venting. The flue hood assembly must be installed as indicated in this section of the unit installation instructions.

Install the flue hood as follows:

1. This installation must conform with local building codes and with the National Fuel Gas Code (NFGC), ANSI Z223.1

(in Canada, CAN/CGA B149.1, and B149.2) or NFPA

(National Fire Protection Association) latest revision.

Refer to Provincial and local plumbing or wastewater codes and other applicable local codes.

2. Remove flue hood from shipping location (inside the blower compartment). Place vent cap assembly over flue panel.

Orient screw holes in vent cap with holes in the flue panel.

3. Secure flue hood to flue panel by inserting a single screw on the right side and the left side of the hood.

Step 8 — Install Gas Piping —

The gas supply pipe enters the unit through the access hole provided. The gas connection to the unit is made to the 1 ⁄

2

-in. FPT gas inlet on the manual shutoff or gas valve.

Install a gas supply line that runs to the heating section.

Refer to Table 3 and the NFGC for gas pipe sizing. Do not

use cast-iron pipe. It is recommended that a black iron pipe is used. Check the local utility for recommendations concerning existing lines. Size gas supply piping for 0.5 in. wg maximum pressure drop. Never use pipe smaller than the

1 ⁄

2

-in. FPT gas inlet on the unit gas valve.

For natural gas applications, the gas pressure at unit gas connection must not be less than 4.0 in. wg or greater than

13 in. wg while the unit is operating. For propane applications, the gas pressure must not be less than 4.0 in. wg or greater than 13 in. wg at the unit connection.

An 1 ⁄

8

-in. NPT plugged tapping accessible for test gage connection must be installed immediately upstream of the gas supply connection to the gas valve.

When installing the gas supply line, observe local codes pertaining to gas pipe installations. Refer to the NFGC ANSI

Z223.1-1988 NFPA latest edition (in Canada, CAN/CGA

B149.1, (2)-M86). In the absence of local building codes, adhere to the following pertinent recommendations:

1. Avoid low spots in long runs of pipe. Grade all pipe

1 ⁄

4 inch in every 15 ft to prevent traps. Grade all horizontal runs downward to risers. Use risers to connect to heating section and to meter.

2. Protect all segments of piping system against physical and thermal damage. Support all piping with appropriate straps, hangers, etc. Use a minimum of one hanger every 6 ft.

For pipe sizes larger than 1 ⁄

2 in., follow recommendations of national codes.

3. Apply joint compound (pipe dope) sparingly and only to male threads of joint when making pipe connections. Use only pipe dope that is resistant to action of liquefied petroleum gases as specified by local and/or national codes.

Never use Teflon tape.

4. Install sediment trap in riser leading to heating section per Fig. 8. This drip leg functions as a trap for dirt and condensate.

5. Install an accessible, external, manual main shutoff valve in gas supply pipe within 6 ft of heating section.

6. Install ground-joint union close to heating section between unit manual shutoff and external manual main shutoff valve.

7. Pressure-test all gas piping in accordance with local and national plumbing and gas codes before connecting piping to unit.

NOTE: Pressure test the gas supply system after the gas supply piping is connected to the gas valve. The supply piping must be disconnected from the gas valve during the testing of the piping systems when test pressure is in excess of 0.5 psig (13.8 WC). Pressure test the gas supply piping system at pressures equal to or less than

0.5 psig. The unit heating section must be isolated from the gas piping system by closing the external main manual shutoff valve and slightly opening the ground-joint union.

7

Table 1 — Physical Data — Unit 48GS

UNIT SIZE 48GS

NOMINAL CAPACITY (ton)

OPERATING WEIGHT (lb)

COMPRESSORS

Quantity

REFRIGERANT (R-22)

Quantity (lb)

REFRIGERANT METERING DEVICE

Orifice ID (in.)

CONDENSER COIL

Rows...Fins/in.

Face Area (sq ft)

CONDENSER FAN

Nominal Cfm

Diameter (in.)

Motor Hp (Rpm)

EVAPORATOR COIL

Rows ...Fins/in.

Face Area (sq ft)

EVAPORATOR BLOWER

Nominal Airflow (Cfm)

Size (in.)

Motor (Hp)

FURNACE SECTION*

Burner Orifice No. (Qty...Drill Size)

Natural Gas

Burner Orifice No. (Qty...Drill Size)

Propane Gas

RETURN-AIR FILTERS (in.)†

Throwaway

018040

1 1 ⁄

2

249

2.6

.034

1...17

6.1

3.5

.034

3.5

.034

3.65

.034

3.65

3.75

Acutrol™ Device

.034

.032

3.75

.032

5.7

.034

5.7

.034

2000

22

2400

22

2400

22

2400

22

2400

22

3000

22

3000

22

3000

22

3000

22

1 ⁄

8

(825) 1 ⁄

8

(825) 1 ⁄

8

(825) 1 ⁄

8

(825) 1 ⁄

8

(825) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100)

2...15

3.1

600

10 x 10

1 ⁄

4

2...45

2...50

20 x 20

024040

1

2

280

1...17

9.1

2...15

3.1

800

10 x 10

⁄

4

2...45

2...50

20 x 20

024060

1

2

280

1...17

9.1

2...15

3.1

800

10 x 10

⁄

4

2...38

2...46

20 x 20

030040

2

1

1 ⁄

⁄

4

2

280

1...17

9.1

2...15

3.1

1000

10 x 10

2...45

2...50

20 x 20

030060

2

1

1

⁄

4

⁄

2

280

2...15

3.1

1000

10 x 10

20 x 20

036060

Reciprocating

1

1...17

9.1

2...38

2...46

1

3

314

1...17

9.1

3...15

3.1

1200

11 x 10

⁄

2

2...38

2...46

20 x 24

036090

1

3

314

1...17

9.1

3...15

3.1

1200

11 x 10

⁄

2

3...38

3...46

20 x 24

042060

3 1 ⁄

2

355

1...17

9.1

4...15

3.1

1400

11 x 10

3 ⁄

4

2...38

2...46

20 x 24

042090

3 1 ⁄

2

355

1...17

9.1

4...15

3.1

1400

11 x 10

3 ⁄

4

3...38

3...46

20 x 24

UNIT SIZE 48GS

NOMINAL CAPACITY (ton)

OPERATING WEIGHT (lb)

COMPRESSORS

Quantity

REFRIGERANT (R-22)

Quantity (lb)

REFRIGERANT METERING DEVICE

Orifice ID (in.)

CONDENSER COIL

Rows...Fins/in.

Face Area (sq ft)

CONDENSER FAN

Nominal Cfm

Diameter (in.)

Motor Hp (Rpm)

EVAPORATOR COIL

Rows Fins/in.

Face Area (sq ft)

EVAPORATOR BLOWER

Nominal Airflow (Cfm)

Size (in.)

Motor (Hp)

FURNACE SECTION*

Burner Orifice No. (Qty...Drill Size)

Natural Gas

Burner Orifice No. (Qty...Drill Size)

Propane Gas

RETURN-AIR FILTERS (in.)†

Throwaway

048090

415

6.0

.032

1...17

12.3

3...15

4.7

1600

3

4

⁄

4

3...38

3...46

24 x 30

048115

4

415

Scroll

1

6.0

.032

1...17

12.3

3...15

4.7

1600

11 x 10 11 x 10

3

⁄

4

3...33

3...42

24 x 30

048130 060090

4 5

415 450

6.0

Acutrol Device

.032

1...17

12.3

3...15

4.7

1600

11 x 10 11 x 10

3

⁄

4

3...31

3...41

24 x 30

8.0

.030

2...17

12.3

4...15

4.7

2000

1.0

3...38

3...46

24 x 30

060115

5

450

Reciprocating

1

8.0

.030

2...17

12.3

060130

5

450

2...17

12.3

3600

22

3600

22

3600

22

3600

22

3600

22

3600

22

1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100)

4...15

4.7

2000

11 x 10

1.0

3...33

3...42

24 x 30

8.0

.030

4...15

4.7

2000

11 x10

1.0

3...31

3...41

24 X 30

*Based on altitude of 0 to 2000 feet.

†Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of

300 ft/min for throwaway type or 450 ft/min for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.

8

UNIT SIZE 48GX

NOMINAL CAPACITY (ton)

OPERATING WEIGHT (lb)

COMPRESSORS

Quantity

REFRIGERANT (R-22)

Quantity (lb)

REFRIGERANT METERING DEVICE

Orifice ID (in.)

CONDENSER COIL

Rows...Fins/in.

Face Area (sq ft)

CONDENSER FAN

Nominal Cfm

Diameter (in.)

Motor Hp (Rpm)

EVAPORATOR COIL

Rows ...Fins/in.

Face Area (sq ft)

EVAPORATOR BLOWER

Nominal Airflow (Cfm)

Size (in.)

Motor (Hp)

FURNACE SECTION*

Burner Orifice No. (Qty...Drill Size)

Natural Gas

Burner Orifice No. (Qty...Drill Size)

Propane Gas

RETURN-AIR FILTERS (in.)†

Throwaway

1...17

9.1

2350

22

1 ⁄

8

(825)

3...15

3.1

800

10 x 10

1 ⁄

4

Table 2 — Physical Data — Unit 48GX

024040

2

290

024060

2

290

030040

2 1 ⁄

2

313

030060

2 1 ⁄

2

313

036060

3

321

Scroll

1

3.4

.034

3.4

.034

4.4

.030

4.4

.030

5.2

.032

1...17

9.1

2350

22

1 ⁄

8

(825)

3...15

3.1

800

10 x 10

1 ⁄

4

1...17

12.7

2350

22

1 ⁄

8

(825)

3...15

3.1

1000

10 x 10

1 ⁄

4

1...17

12.7

2350

22

1 ⁄

8

(825)

3...15

3.1

1000

10 x 10

1 ⁄

4

2...17

9.1

2350

22

1 ⁄

8

(825)

3...15

3.7

1200

11 x 10

1 ⁄

2

2...44

2...50

20 x 20

2...38

2...46

20 x 20

2...44

2...50

20 x 20

2...38

2...46

20 x 20

2...38

2...46

20 x 24

036090

3

321

042060

3 1 ⁄

2

382

042090

3 1 ⁄

2

382

5.2

.032

2...17

9.1

2350

22

1 ⁄

8

(825)

3...15

3.7

1200

11 x 10

1 ⁄

2

3...38

3...46

6.4

.034

2...17

12.3

3300

22

1 ⁄

4

(1100)

3...15

4.7

1400

11 x 10

3 ⁄

4

2...38

2...46

6.4

.034

2...17

12.3

3300

22

1 ⁄

4

(1100)

3...15

4.7

1400

11 x 10

3 ⁄

4

3...38

3...46

20 x 24 24 x 30 24 x 30

UNIT SIZE 48GX

NOMINAL CAPACITY (ton)

OPERATING WEIGHT (lb)

COMPRESSORS

Quantity

REFRIGERANT (R-22)

Quantity (lb)

REFRIGERANT METERING DEVICE

Orifice ID (in.)

CONDENSER COIL

Rows...Fins/in.

Face Area (sq ft)

CONDENSER FAN

Nominal Cfm

Diameter (in.)

Motor Hp (Rpm)

EVAPORATOR COIL

Rows Fins/in.

Face Area (sq ft)

EVAPORATOR BLOWER

Nominal Airflow (Cfm)

Size (in.)

Motor (Hp)

FURNACE SECTION*

Burner Orifice No. (Qty...Drill Size)

Natural Gas

Burner Orifice No. (Qty...Drill Size)

Propane Gas

RETURN-AIR FILTERS (in.)†

Throwaway

048090

4

421

7.2

.034

2...17

12.3

048115

4

421

2...17

12.3

048130

4

421

7.2

060090

Scroll

1

5

468

8.1

Acutrol Device

.034

2...17

12.3

1600

11 x 10 11 x 10

3

⁄

4

.032

2...17

16.4

1750

1.0

060115

5

468

2...17

16.4

060130

5

468

2...17

16.4

3300

22

3300

22

3300

22

3300

22

3300

22

3300

22

1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100) 1 ⁄

4

(1100)

4...15

4.7

1600

11 x 10

3

⁄

4

3...38

3...46

24 x 30

7.2

.034

4...15

4.7

1600

11 x 10

3

⁄

4

3...33

3...42

24 x 30

4...15

4.7

3...31

3...41

24 x 30

4...15

4.7

3...38

3...46

24 x 30

8.1

.032

4...15

4.7

1750

11 x 10

1.0

3...33

3...42

24 x 30

8.1

.032

4...15

4.7

1750

11 x10

1.0

3...31

3...41

24 X 30

*Based on altitude of 0 to 2000 feet.

†Required filter sizes shown are based on the larger of the ARI (Air Conditioning and Refrigeration Institute) rated cooling airflow or the heating airflow velocity of

300 ft/min for throwaway type or 450 ft/min for high-capacity type. Air filter pressure drop for non-standard filters must not exceed 0.08 in. wg.

9

(Text continued from page 7)

Unstable operation may occur when the gas valve and manifold assembly are forced out of position while connecting improperly-routed rigid gas piping to the gas valve. Use a backup wrench when making connection to avoid strain on, or distortion of, the gas control piping.

If a flexible conductor is required or allowed by the authority having jurisdiction, black iron pipe shall be installed at the gas valve and shall extend a minimum of 2 in. outside the unit casing.

Never use a match or other open flame when checking for gas leaks. Never purge gas line into combustion chamber. Failure to follow this warning could result in an explosion causing personal injury or death.

8. Check for gas leaks at the field-installed and factoryinstalled gas lines after all piping connections have been completed. Use soap-and-water solution (or method specified by local codes and/or regulations).

Fig. 8 — Sediment Trap

Step 9 — Install Duct Connections —

The unit has duct flanges on the supply- and return-air openings on the side and bottom of the unit. For downshot applications the ductwork connects to the roof curb. See Fig. 2 and 3 for connection sizes and locations.

CONFIGURING UNITS FOR DOWNFLOW (VERTI-

CAL) DISCHARGE

Before performing service or maintenance operations on the system, turn off main power to unit or electrical shock could result.

1. Open all electrical disconnects before starting any service work.

2. Remove return duct cover located on duct panel by breaking connecting tabs with screwdriver and a hammer

(Fig. 9).

3. To remove supply duct cover, break front and right side connecting tabs with a screwdriver and a hammer. Push louver down to break rear and left side tabs (Fig. 10).

4. If unit ductwork is to be attached to vertical opening flanges on the unit basepan (jackstand applications only), do so at this time.

5. It is recommended that the basepan insulation around the perimeter of the vertical return-air opening be secured to the basepan with aluminum tape. Applicable local codes may require aluminum tape to prevent exposed fiberglass.

6. Cover both horizontal duct openings with the duct covers from the accessory duct cover kit. Ensure opening is airand watertight.

7. After completing unit conversion, perform all safety checks and power up unit.

NOTE: The design and installation of the duct system must be in accordance with the standards of the NFPA for installation of nonresidence-type air conditioning and ventilating systems, NFPA 90A or residence-type, NFPA 90B; and/or local codes and residence-type, NFPA 90B; and/or local codes and ordinances.

Adhere to the following criteria when selecting, sizing, and installing the duct system:

1. Units are shipped for horizontal duct installation.

2. Select and size ductwork, supply-air registers, and return-air grilles according to American Society of

Heating, Refrigeration and Air Conditioning Engineers

(ASHRAE) recommendations.

3. Use flexible transition between rigid ductwork and unit to prevent transmission of vibration. The transition may be screwed or bolted to duct flanges. Use suitable gaskets to ensure weathertight and airtight seal.

4. All units must have field-supplied filters or accessory filter rack installed in the return-air side of the unit. Recommended sizes for filters are shown in Tables 1 and 2.

5. Size all ductwork for maximum required airflow (either heating or cooling) for unit being installed. Avoid abrupt duct size increases or decreases or performance may be affected.

6. Adequately insulate and weatherproof all ductwork located outdoors. Insulate ducts passing through unconditioned space, and use vapor barrier in accordance with latest issue of Sheet Metal and Air Conditioning

Contractors National Association (SMACNA) and Air

Conditioning Contractors of America (ACCA) minimum installation standards for heating and air conditioning systems. Secure all ducts to building structure.

7. Flash, weatherproof, and vibration-isolate all openings in building structure in accordance with local codes and good building practices.

10

Table 3 — Maximum Gas Flow Capacity*

NOMINAL

IRON PIPE,

SIZE

(in.)

1

3

1

1

⁄

2

⁄

4

1

1

1

⁄

⁄

4

2

INTERNAL

DIAMETER

(in.)

.622

.824

1.049

1.380

1.610

10

175

360

680

1400

2100

20

120

250

465

950

1460

30

97

200

375

770

1180

40

82

170

320

600

990

50

73

151

285

580

900

LENGTH OF PIPE, FT†

60

66

138

260

530

810

70

61

125

240

490

750

80

57

118

220

460

690

90

53

110

205

430

650

100

50

103

195

400

620

*Capacity of pipe in cu ft of gas per hr for gas pressure of 0.5 psig or less. Pressure drop of 0.5-in. wg (based on a 0.60 specific gravity gas). Refer to Table C-4, National Fire Protection Association NFPA 54.

†This length includes an ordinary number of fittings.

125

44

93

175

360

550

150

40

84

160

325

500

175

—

77

145

300

460

200

—

72

135

280

430

Step 10 — Install Electrical Connections

The unit cabinet must have an uninterrupted, unbroken electrical ground to minimize the possibility of personal injury if an electrical fault should occur. This ground may consist of an electrical wire connected to the unit ground lug in the control compartment, or conduit approved for electrical ground when installed in accordance with NEC (National Electrical Code) ANSI/

NFPA (latest edition) (in Canada, Canadian Electrical

Code CSA [Canadian Standards Association] C22.1) and local electrical codes. Do not use gas piping as an elec-

trical ground. Failure to adhere to this warning could result in personal injury or death.

Fig. 9 — Supply and Return Duct Openings

Failure to follow these precautions could result in damage to the unit being installed:

1. Make all electrical connections in accordance with NEC

ANSI/NFPA (latest edition) and local electrical codes governing such wiring. In Canada, all electrical connections must be in accordance with CSA standard C22.1 Canadian Electrical Code Part 1 and applicable local codes.

Refer to unit wiring diagram.

2. Use only copper conductor for connections between fieldsupplied electrical disconnect switch and unit. DO NOT

USE ALUMINUM WIRE.

3. Be sure that high-voltage power to unit is within operating voltage range indicated on unit rating plate.

4. Do not damage internal components when drilling through any panel to mount electrical hardware, conduit, etc.

5. On 3-phase units, ensure phases are balanced within 2%.

Consult local power company for correction of improper voltage and/or phase imbalance (refer to Tables 4 and 5).

HIGH-VOLTAGE CONNECTIONS — The unit must have a separate electrical service with a field-supplied, waterproof, disconnect switch mounted at, or within sight from, the unit. Refer to the unit rating plate for maximum fuse/ circuit breaker size and minimum circuit amps (ampacity) for wire sizing. See Tables 4 and 5 for electrical data.

The field-supplied disconnect switch box may be mounted on the unit over the high-voltage inlet hole when the standard power and low-voltage entry points are used. See

Fig. 2 and 3 for acceptable location.

See unit wiring label and Fig. 11 for reference when making high voltage connections. Proceed as follows to complete the high-voltage connections to the unit.

Fig. 10 — Vertical Duct Cover Removed

11

Single phase units:

1. Run the high-voltage (L1, L2) and ground leads into the control box.

2. Connect ground lead to chassis ground connection.

3. Connect L1 to pressure lug connection 11 of the compressor contactor.

4. Connect L2 to pressure lug connection 23 of the compressor contactor.

Three phase units:

1. Run the high-voltage (L1, L2, L3) and ground leads into the control box.

2. Connect ground lead to chassis ground connection.

3. Locate the black and yellow wires connected to the lines side of the contactor.

4. Connect field L1 to black wire on connection 11 of the compressor contactor.

5. Connect field wire L2 to yellow wire on connection 13 of the compressor contactor.

6. Connect field wire L3 to Blue wire from compressor.

SPECIAL PROCEDURES FOR 208-V OPERATION

Make sure that the gas supply then the power supply to the unit is switched OFF before making any wiring changes. Electrical shock can cause personal injury or death.

With disconnect switch open, move yellow wire from transformer ( 3 ⁄

16 in.) terminal marked 230 to terminal marked 200.

This retaps transformer to primary voltage of 208 vac.

UNIT

SIZE

48GS

018

024

030

036

042

048

060

V-PH-Hz

208/230-1-60

208/230-1-60

208/230-1-60

208/230-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

208-230/1/60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

187

187

414

187

187

414

197

187

414

187

187

414

VOLTAGE

RANGE

Min Max

187

187

187

187

253

253

253

253

253

506

253

253

506

253

253

506

253

253

506

253

COMPRESSOR

5.8

18.6

10.7

5.3

25.3

13.5

6.7

28.9

18.6

8.5

RLA

9.0

12.8

14.4

12.6

15.1

10.9

40.0

105.0

85.0

42.0

131.0

108.0

47.5

147.0

125.0

66.5

LRA

45.0

61.0

73.0

68.0

81.0

78.0

LEGEND

FLA

— Full Load Amps

HACR — Heating, Air Conditioning and Refrigeration

LRA

— Locked Rotor Amps

MCA

— Minimum Circuit Amps

MOCP — Maximum Overcurrent Protection

RLA

— Rated Load Amps

*Fuse or HACR Breaker.

NOTES:

1. In compliance with NEC (National Electrical Code) requirements for multimotor and combination load equipment (refer to NEC

Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. The CGA (Canadian Gas

Association) units may be fuse or circuit breaker.

2. Minimum wire size is based on 60 C copper wire. If other than

60 C wire is used, or if length exceeds wire length in table, determine size from NEC.

3. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply voltage is greater than 2%.

Use the following formula to determine the percentage of voltage imbalance.

% Voltage imbalance

= 100 x max voltage deviation from average voltage average voltage

Table 4 — Electrical Data — Unit 48GS

OUTDOOR FAN

MOTOR

FLA

0.8

0.8

0.8

0.8

1.6

1.6

0.9

1.6

1.6

0.9

1.6

1.6

0.9

1.6

1.6

0.9

INDOOR FAN

MOTOR

FLA

1.8

2.0

2.0

2.0

3.6

3.6

1.9

3.8

3.8

2.0

3.8

3.8

2.0

6.2

6.2

3.2

POWER SUPPLY FUSE OR

HACR BRKR

MCA MOCP*

13.9

18.8

20.8

13.2

20

30

30

20

22.3

11.3

43.9

31.1

14.7

24.1

18.8

10.1

27.5

18.8

9.5

37.0

35

25

15

45

25

15

60

35

15

60

45

20

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

Average Voltage =

452

1

464

1

455

3

=

1371

3

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 452 = 5 v

(BC) 464 − 457 = 7 v

(AC) 457 − 455 = 2 v

Maximum deviation is 7 v.

Determine percent of voltage imbalance.

% Voltage Imbalance = 100 x

7

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.

12

UNIT

SIZE

48GX

024

030

036

042

048

060

V-PH-Hz

208/230-1-60

208/230-1-60

208/230-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

208/230-1-60

208/230-3-60

460-3-60

187

414

187

187

414

187

187

414

VOLTAGE

RANGE

Min

187

Max

253

187

187

187

253

253

253

187

187

414

253

253

506

253

506

253

253

506

253

253

506

COMPRESSOR

RLA

10.3

13.5

9.0

16.7

11.2

5.4

17.9

12.4

6.1

19.5

12.4

5.8

28.8

17.3

9.0

LEGEND

FLA

— Full Load Amps

HACR — Heating, Air Conditioning and Refrigeration

LRA

— Locked Rotor Amps

MCA

— Minimum Circuit Amps

MOCP — Maximum Overcurrent Protection

RLA

— Rated Load Amps

*Fuse or HACR Breaker.

NOTES:

1. In compliance with NEC (National Electrical Code) requirements for multimotor and combination load equipment (refer to NEC

Articles 430 and 440), the overcurrent protective device for the unit shall be fuse or HACR breaker. The CGA (Canadian Gas

Association) units may be fuse or circuit breaker.

2. Minimum wire size is based on 60 C copper wire. If other than

60 C wire is used, or if length exceeds wire length in table, determine size from NEC.

3. Unbalanced 3-Phase Supply Voltage

Never operate a motor where a phase imbalance in supply voltage is greater than 2%.

Use the following formula to determine the percentage of voltage imbalance.

% Voltage imbalance

= 100 x max voltage deviation from average voltage average voltage

LRA

56.0

73.0

63.0

97.0

75.0

37.5

104.0

88.0

44.0

104.0

88.0

44.0

169.0

123.0

62.0

Table 5 — Electrical Data — Unit 48GX

OUTDOOR FAN

MOTOR

FLA

0.8

0.8

0.8

0.8

0.9

1.6

1.6

0.9

0.8

0.9

1.6

1.6

1.6

1.6

0.9

INDOOR FAN

MOTOR

FLA

2.0

2.1

2.1

3.6

2.0

4.1

4.1

2.0

3.6

1.9

4.1

4.1

6.2

6.2

3.2

POWER SUPPLY FUSE OR

HACR BRKR

MCA

15.7

MOCP*

25

19.8

14.2

25.3

30

20

40

18.4

9.6

28.1

21.2

10.5

30.1

21.2

10.2

43.8

29.4

15.4

25

15

45

30

15

45

30

15

60

45

20

EXAMPLE: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

Average Voltage =

452

1

464

1

455

3

=

1371

3

= 457

Determine maximum deviation from average voltage.

(AB) 457 − 452 = 5 v

(BC) 464 − 457 = 7 v

(AC) 457 − 455 = 2 v

Maximum deviation is 7 v.

Determine percent of voltage imbalance.

% Voltage Imbalance = 100 x

7

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.

13

PRE-START-UP

HIGH VOLTAGE

POWER LEADS

(SEE UNIT WIRING

LABEL)

POWER

SUPPLY

FIELD-SUPPLIED

FUSED DISCONNECT

GND

CONTROL BOX

LOW-VOLTAGE

POWER LEADS

(SEE UNIT

WIRING LABEL)

WHT(W1)

YEL(Y)

GRN(G)

RED(R)

BRN(C)

W

Y

G

R

C

THERMOSTAT

(TYPICAL)

SPLICE BOX

LEGEND

Field Control-Voltage Wiring

Field High-Voltage Wiring

NOTE: Use blue wire for 3-phase units only.

Fig. 11 — High- and Control-Voltage Connections

CONTROL VOLTAGE CONNECTIONS

NOTE: Do not use any type of power-stealing thermostat.

Unit control problems may result.

Use no. 18 American Wire Gage (AWG) color-coded, insulated (35 C minimum) wires to make the control voltage connections between the thermostat and the unit. If the thermostat is located more than 100 ft from the unit (as measured along the control voltage wires), use no. 16 AWG colorcoded, insulated (35 C minimum) wires.

Standard Connection — Remove knockout hole located in the flue panel adjacent to the control access panel. See

Fig. 2 and 3. Remove the rubber grommet from the installer’s packet (included with unit) and install grommet in the knockout opening. Provide a drip loop before running wire through panel.

Run the low-voltage leads from the thermostat, through the inlet hole, and into unit low-voltage splice box.

Locate five 18-gage wires leaving control box. These lowvoltage connection leads can be identified by the colors red, green, yellow, brown, and white. (See Fig. 11.) Ensure the leads are long enough to be routed into the low-voltage splice box (located below right side of control box). Stripped yellow wire is located in connection box. Route leads through hole in bottom of control box and make low-voltage connections as shown in Fig. 11. Secure all cut wires, so that they do not interfere with operation of unit.

HEAT ANTICIPATOR SETTING — The room thermostat heat anticipator must be properly adjusted to ensure proper heating performance. Set the heat anticipator, using an ammeter between the W and R terminals to determine the exact required setting.

NOTE: For thermostat selection purposes, use 0.18 amp for the approximate required setting.

Failure to make a proper heat anticipator adjustment will result in improper operation, discomfort to the occupants of the conditioned space, and inefficient energy utilization; however, the required setting may be changed slightly to provide a greater degree of comfort for a particular installation.

TRANSFORMER PROTECTION — The transformer is of the energy-limiting type. It is set to withstand a 30-second overload or shorted secondary condition.

14

Failure to observe the following warnings could result in serious personal injury:

1. Follow recognized safety practices and wear protective goggles and gloves when checking or servicing refrigerant system.

2. Do not operate compressor or provide any electric power to unit unless compressor terminal cover is in place and secured.

3. Do not remove compressor terminal cover until all electrical sources are disconnected.

4. Relieve and recover all refrigerant from system before touching or disturbing anything inside terminal box if refrigerant leak is suspected around compressor terminals.

5. Never attempt to repair soldered connection while refrigerant system is under pressure.

6. Do not use torch to remove any component. System contains oil and refrigerant under pressure. To remove a component, wear protective goggles and gloves.

Proceed as follows: a. Shut off gas supply and then electrical power to unit.

b. Relieve and recover all refrigerant from system using both high- and low-pressure ports.

c. Cut component connecting tubing with tubing cutter and remove component from unit.

d. Carefully unsweat remaining tubing stubs when necessary. Oil can ignite when exposed to torch flame.

Proceed as follows to inspect and prepare the unit for initial start-up:

1. Remove access panel.

2. Read and follow instructions on all WARNING, CAU-

TION, and INFORMATION labels attached to, or shipped with, unit.

3. Make the following inspections: a. Inspect for shipping and handling damages such as broken lines, loose parts, disconnected wires, etc.

b. Inspect for oil at all refrigerant tubing connections and on unit base. Detecting oil generally indicates a refrigerant leak.

c. Leak-test all refrigerant tubing connections using electronic leak detector, halide torch, or liquid-soap solution. If a refrigerant leak is detected, see Check for

Refrigerant Leaks section on page 15.

d. Inspect all field and factory-wiring connections. Be sure that connections are completed and tight.

e. Inspect coil fins. If damaged during shipping and handling, carefully straighten fins with a fin comb.

4. Verify the following conditions:

Do not purge gas supply into the combustion chamber. Do not use a match or other open flame to check for gas leaks. Failure to follow this warning could result in an explosion causing personal injury or death.

a. Before lighting the unit for the first time, perform the following with the gas valve in the ‘‘OFF’’ position: If the gas supply pipe was not purged before connecting the unit, it will be full of air. It is recommended that the ground joint union be loosened, and the supply line be allowed to purge until the odor of gas is detected.

Never purge gas lines into a combustion chamber. Immediately upon detection of gas odor, retighten the union.

Allow 5 minutes to elapse, then light unit.

b. Make sure that condenser-fan blade is correctly positioned in fan orifice. Leading edge of condenser-fan blade should be 1 ⁄

2 in. maximum from fan orifice.

c. Ensure fan hub is

1

⁄

8 in. max from motor housing (see

Fig. 12).

d. Make sure that air filter(s) is in place.

e. Make sure that condensate drain trap is filled with water to ensure proper drainage.

f. Make sure that all tools and miscellaneous loose parts have been removed.

MOTOR

FAN GRILLE

1/8" MAX BETWEEN

MOTOR AND FAN HUB

MOTOR SHAFT

Fig. 12 — Fan Blade Clearance

START-UP

Check for Refrigerant Leaks —

Proceed as follows to locate and repair a refrigerant leak and to charge the unit:

1. Locate leak and make sure that refrigerant system pressure has been relieved and refrigerant recovered from both high- and low-pressure ports.

2. Repair leak following standard Refrigerant Service procedures.

NOTE: Install a filter drier whenever the system has been opened for repair.

3. Add a small charge of R-22 refrigerant vapor to system and leak-test unit.

4. Evacuate and recover refrigerant from refrigerant system if additional leaks are not found.

5. Charge unit with R-22 refrigerant, using a volumetriccharging cylinder or accurate scale. Refer to unit rating

plate for required charge. Be sure to add extra refrigerant to compensate for internal volume of filter drier.

Start Up Heating Section and Make

Adjustments

Complete the required procedures given in Pre-Start-Up section on page 14 before starting the unit.

Do not jumper any safety devices when operating the unit.

Make sure that burner orifices are properly aligned. Unstable operation may occur when the burner orifices in the manifold are misaligned.

Follow the lighting instructions on the heating section operation label (located inside the burner or blower access door) to start the heating section.

NOTE: Make sure that gas supply has been purged, and that all gas piping has been checked for leaks.

CHECK HEATING CONTROL — Start and check the unit for proper heating control operation as follows. (See furnace lighting instructions located inside burner or blower access panel.)

1. Place the room thermostat SYSTEM switch in the HEAT position and the fan switch in the AUTO. position.

2. Set the heating temperature control of the thermostat above room temperature.

3. The induced-draft motor will start.

4. After a call for heating, the main burner should light within 5 seconds. If the burners do not light, there is a

22-second delay before another 5-second try. If the burners still do not light, this sequence is repeated. If the burners do not light within 15 minutes from the initial call for heat, there is a lockout. To reset the control, break the

24-v power to W.

5. The evaporator fan will turn on 45 seconds after the flame has been established. The evaporator fan will turn off

45 seconds after the thermostat has been satisfied.

CHECK GAS INPUT — Check gas input and manifold pressure after unit start-up. (See Table 6.) If adjustment is required proceed as follows.

The rated gas inputs shown in Table 6 are for altitudes from sea level to 2000 ft above sea level. These inputs are based on natural gas with a heating value of

1050 Btu/ft

3 at 0.65 specific gravity, or propane gas with a heating value of 2500 Btu/ft

3 at 1.5 specific gravity.

For elevations above 2000 ft, reduce input 4% for each

1000 ft above sea level. When the gas supply being used has a different heating value or specific gravity, refer to national and local codes, or contact your distributor to determine the required orifice size.

These units are designed to consume the rated gas inputs using the fixed orifices at specified manifold pressures as shown in Table 6. DO NOT REDRILL THE

ORIFICES UNDER ANY CIRCUMSTANCES.

15

Table 6 — Heating Inputs

HEATING

INPUT

(Btuh)*

40,000

60,000

90,000

115,000

130,000

NUMBER

OF

ORIFICES

2

2

3

3

3

Min

4.0

4.0

4.0

4.0

4.0

GAS SUPPLY PRESSURE

(in. wg)

Natural Propane†

Max Min Max

13.0

13.0

13.0

13.0

13.0

4.0

4.0

4.0

4.0

4.0

13.0

13.0

13.0

13.0

13.0

* When a unit is converted to propane, different size orifices must be used. See separate naturalto-propane conversion kit instructions.

†Based on altitudes from sea level to 2000 ft above sea level. For altitudes above 2000 ft, reduce input rating 4% for each additional 1000 ft above sea level. In Canada, from 2000 ft above sea level to 4500 ft above sea level, derate the unit 10%.

ADJUST GAS INPUT — The gas input to the unit is determined by measuring the gas flow at the meter or by measuring the manifold pressure. Measuring the gas flow at the meter is recommended for natural gas units. The manifold pressure must be measured to determine the input of propane gas units.

Measure Gas Flow (Natural Gas Units) — Minor adjustment to the gas flow can be made by changing the manifold pressure. The manifold pressure must be maintained between 3.4 and 3.6 in. wg. If larger adjustments are required, change main burner orifices following the recommendations of national and local codes.

NOTE: All other appliances that use the same meter must be turned off when gas flow is measured at the meter.

Proceed as follows:

1. Turn off gas supply to unit.

2. Remove pipe plug on manifold (see Fig. 13) then connect manometer at this point. Turn on gas to unit.

3. Record number of seconds for gas meter test dial to make one revolution.

4. Divide number of seconds in Step 3 into 3600 (number of seconds in one hour).

5. Multiply result of Step 4 by the number of cu ft shown for one revolution of test dial to obtain cu ft of gas flow per hour.

6. Multiply result of Step 5 by Btu heating value of gas to obtain total measured input in Btuh. Compare this value with heating input shown in Table 6. (Consult the local gas supplier if the heating value of gas is not known.)

EXAMPLE: Assume that the size of test dial is 1 cu ft, one revolution takes 32 seconds, and the heating value of the gas is 1050 Btu/ft

3

. Proceed as follows:

1. 32 seconds to complete one revolution.

2. 3600 ÷ 32 = 112.5.

3. 112.5 x 1 = 112.5 ft

3 of gas flow/hr.

4. 112.5 x 1050 = 118,125 Btuh input.

If the desired gas input is 115,000 Btuh, only a minor change in the manifold pressure is required.

Natural

3.5

3.5

3.5

3.5

3.5

MANIFOLD

PRESSURE

(in. wg)

Propane†

3.5

3.5

3.4

3.7

3.5

Fig. 13 — Burner Assembly

Observe manifold pressure and proceed as follows to adjust gas input:

1. Remove cover screw over regulator adjustment screw on gas valve.

2. Turn regulator adjustment screw clockwise to increase gas input, or turn regulator adjustment screw counterclockwise to decrease input. Manifold pressure must be between 3.4 and 3.6 in. wg.

Unsafe operation of the unit may result if manifold pressure is outside this range. Personal injury or unit damage may result.

3. Replace cover screw cap on gas valve.

4. Turn off gas supply to unit. Remove manometer from pressure tap and replace pipe plug on gas valve. Turn on gas to unit and check for leaks.

16

Measure Manifold Pressure (Propane Units) — The main burner orifices on a propane gas unit are sized for the unit rated input when the manifold pressure reading matches the level specified in Table 6.

Proceed as follows to adjust gas input on a propane gas unit:

1. Turn off gas to unit.

2. Remove pipe plug on manifold (see Fig. 13), then connect manometer at this point.

3. Turn on gas to unit.

4. Remove cover screw over regulator adjustment screw on gas valve.

5. Adjust regulator adjustment screw to the correct manifold pressure, as specified in Table 6. Turn adjusting screw clockwise to increase manifold pressure, or turn adjusting screw counterclockwise to decrease manifold pressure.

6. Replace cover screw.

7. Turn off gas to unit. Remove manometer from pressure tap. Replace pipe plug on gas valve, then turn on gas to unit. Check for leaks.

CHECK BURNER FLAME — With burner access panel removed, observe the unit heating operation. Watch the burner flames to see if they are light blue and soft in appearance, and that the flames are approximately the same for each burner.

Propane will have blue flame with yellow tips. See Fig. 14.

Refer to Maintenance section for information on burner removal.

Fig. 14 — Monoport Burners

AIRFLOW AND TEMPERATURE RISE — The heating section for each size unit is designed and approved for heating operation within the temperature-rise range stamped on the unit rating plate.

Table 7 shows the approved temperature-rise range for each heating input, and the air delivery cfm at various temperature rises. The heating operation airflow must produce a temperature rise that falls within the approved range.

Refer to Indoor Airflow and Airflow Adjustments section on page 22 to adjust heating airflow when required.

Table 7 — Air Delivery (Cfm) at Indicated Temperature Rise and Rated Heating Input

HEATING

INPUT

(Btuh)

40,000

60,000

90,000

115,000

130,000

20

1500

2250

—

—

—

25

1200

1800

—

—

—

30

1000

1500

2250

—

—

35

857

1286

1929

2464

2786

TEMPERATURE RISE °F

40

750

1125

1688

2156

2438

45

667

1000

1500

1917

2167

NOTE: Dashed areas do not fall within the approved temperature rise range of the unit.

50

600

900

1350

1725

1950

55

545

818

1227

1568

1773

60

500

750

1125

1438

1625

65

—

692

1038

1327

1500

70

—

—

964

1232

—

17

HEATING SEQUENCE OF OPERATION — See Fig. 15-

17 and unit wiring label.

On a call for heating, terminal ‘‘W’’ of the thermostat is energized, starting the induced-draft motor. When the halleffect sensor on the induced-draft motor senses that it has reached the required speed, the burner sequence begins. This function is performed by the integrated gas control (IGC).

The evaporator-fan motor is energized 45 seconds after flame is established. When the thermostat is satisfied and ‘‘W’’ is deenergized, the burners stop firing and the evaporator-fan motor shuts off after a 45-second time-off delay.

An LED (light-emitting diode) indicator is provided on the control board to monitor operation. The control board is located by removing the burner access panel. During normal operation, the LED is continuously on. See Table 8 for error codes.

Table 8 — LED Indications

ERROR CODE

Normal Operation

Hardware Failure

Fan On/Off Delay Modified

Limit Switch Fault

Flame Sense Fault

Four Consecutive Limit Switch Faults

Ignition Lockout Fault

Induced-Draft Motor Fault

Rollout Switch Fault

Internal Control Fault

LED INDICATION

On

Off

1 Flash

2 Flashes

3 Flashes

4 Flashes

5 Flashes

6 Flashes

7 Flashes

8 Flashes

NOTES:

1. There is a 3-second pause between error code displays.

2. If more than one error code exists, all applicable error codes will be displayed in numerical sequence.

3. This chart is on the wiring diagram located inside the burner access panel.

LIMIT SWITCHES — Normally closed limit switch (LS) completes the control circuit through the thermostat R circuit. Should the leaving-air temperature rise above the maximum allowable temperature, the limit switch opens and the R control circuit ‘‘breaks.’’Any interruption in the R control circuit instantly closes the gas valve and stops gas flow to the burners and pilot. The blower motor continues to run until LS resets.

When the air temperature at the limit switch drops to the low-temperature setting of the limit switch, the switch closes and completes the R control circuit. The electricspark ignition system cycles and the unit returns to normal heating operation. When this fault occurs the IGC LED will display FAULT CODE 2.

AUXILIARY LIMIT SWITCH (ROLLOUT) — The function of the switch is to close the main gas valve in the event of flame rollout. The switch is located above the main burners. When the temperature at the auxiliary switch reaches the maximum allowable temperature, the R control circuit trips, closing the gas valve and stopping gas flow to the burners. The indoor (evaporator) fan motor (IFM) and induced draft motor continue to run until switch is reset. The IGC

LED will display FAULT CODE 7.

Start Up Cooling Section and Make

Adjustments

Complete the required procedures given in the Pre-

Start-Up section on page 14 before starting the unit.

Do not jumper any safety devices when operating the unit.

Do not operate the compressor when the outdoor temperature is below 40 F (unless accessory low-ambient kit is installed).

Do not rapid-cycle the compressor. Allow 5 minutes between ‘‘on’’ cycles to prevent compressor damage.

CHECKING COOLING CONTROL OPERATION — Start and check the unit for proper cooling control operation as follows:

1. Place room thermostat SYSTEM switch in OFF position.

Observe that blower motor starts when FAN switch is placed in ON position and shuts down when FAN switch is placed in AUTO. position.

2. Place SYSTEM switch in COOL position and FAN switch in AUTO. position. Set cooling control below room temperature. Observe that compressor, condenser fan, and evaporator blower motors start. Observe that cooling cycle shuts down when control setting is satisfied. The evaporator fan will continue to run for 30 seconds.

3. When using an auto.-changeover room thermostat, place both SYSTEM and FAN switches in AUTO. positions.

Observe that unit operates in Heating mode when temperature control is set to ‘‘call for heating’’ (above room temperature) and operates in Cooling mode when temperature control is set to ‘‘call for cooling’’ (below room temperature).

IMPORTANT: Three-phase, scroll compressor units

(48GS048 and 48GX030-060) are direction-oriented.

These units must be checked to ensure proper compressor 3-phase power lead orientation. If not corrected within 5 minutes, the internal protector will shut off the compressor. The 3-phase power leads to the unit must be reversed to correct rotation. When turning backwards, scroll compressors emit elevated noise levels, and the difference between compressor suction and discharge pressures may be dramatically lower than normal.

(Text continued on page 22.)

18

LEGEND

AHA

BR

C

CAP

—

Adjustable Heat Anticipator

—

Blower Relay

—

Contactor

—

Capacitor

COMP —

Compressor Motor

CR —

Combustion Relay

EQUIP —

Equipment

FS —

Flame Sensor

FU

GND

GVR

HS

HV

TRAN

I

IDM

—

Fuse

—

Ground

—

Gas Valve Relay

—

Hall Effect Sensor

—

High Voltage Transformer

IFM

IGC

LS

MGV

NEC

OFM

—

Ignitor

—

Induced-Draft Motor

—

Indoor-Fan Motor

—

Integrated Gas Unit Controller

—

Limit Switch

—

Main Gas Valve

—

National Electrical Code

—

Outdoor-Fan Motor

QT

RS

—

—

Quadruple Terminal

Rollout Switch

ST —

Thermistor Sensor

TRAN —

Transformer

Field Splice

Terminal (Marked)

Terminal (Unmarked)

Splice

Splice (Marked)

Factory Wiring

Field Control Wiring

Field Power Wiring

Accessory or Optional Wiring

To Indicate Common Potential

Only, Not to Represent Wiring

NOTES:

1. If any of the original wires furnished are replaced, it must be replaced with type

90 degree C wire or its equivalent.

2. See price pages for thermostat and subbases.

3. Use 75 degree C copper conductors for field installation.

4. For high speed IFM, disconnect RED wire from IGC terminal BM and connect

BLK wire from IFM. For medium speed, disconnect RED wire from IGC terminal

BM and connect BLU wire from IFM.

5. Models 48GS018-042 and 48GX024-036 have LS1 and LS2 wired in series.

Models 48GS048,060 and 48GX042-060 have LS1 only.

Fig. 15 — 208/230-1-60 Wiring Diagram, Unit 48GS and 48GX

LEGEND

AHA

BR

C

CAP

— Adjustable Heat Anticipator

— Blower Relay

— Contactor

— Capacitor

COMP

— Compressor Motor

CR

— Combustion Relay

IDM

IFC

IFM

IGC

L1

LS

LS1

MGV

I

CS

— Centrifugal Switch

EQUIP — Equipment

FS

FU

GND

GV

GVR

HS

HV

— Fusible Link

— Fuse

— Ground

— Gas Valve

— Gas Valve Relay

— Hall Effect Sensor

— High Voltage

— Ignitor

— Induced-Draft Motor

— Indoor-Fan Contactor

— Indoor-Fan Motor

— Integrated Gas Unit Controller

— Line

— Limit Switch

— Limit Switch

— Main Gas Valve

NEC

— National Electrical Code

OFM

— Outdoor-Fan Motor

QT

RS

— Quadruple Terminal

— Rollout Switch

SEN

— Sensor

SW

— Switch

TRAN — Transformer

Field Splice

Terminal (Marked)

Terminal (Unmarked)

Splice

Splice (Marked)

Factory Wiring

Field Control Wiring

Field Power Wiring

Accessory or Optional Wiring

To Indicate Common Potential

Only, Not to Represent Wiring

NOTES:

1. If any of the original wires furnished are replaced, they must be replaced with type 90 degree C wire or its equivalent.

2. See price pages for thermostat and subbases.

3. Use 75 degree C copper conductors for field installation.

4. For high speed IFM, disconnect RED wire from IGC terminal BM and connect BLK wire from IFM. For medium speed, disconnect RED wire from IGC terminal BM and connect BLU wire from IFM.

Fig. 16 — 208/230-3-60 Wiring Diagram, Unit 48GS and 48GX

20

AHA

BR

C

CAP

— Adjustable Heat Anticipator

— Blower Relay

— Contactor

— Capacitor

COMP

— Compressor Motor

CR

— Combustion Relay

I

CS

— Centrifugal Switch

EQUIP — Equipment

FS

FU

GND

GV

GVR

HS

HV

— Fusible Link

— Fuse

— Ground

— Gas Valve

— Gas Valve Relay

— Hall Effect Sensor

— High Voltage

— Ignitor

IDM

IFC

IFM

IGC

— Induced-Draft Motor

— Indoor-Fan Contactor

— Indoor-Fan Motor

— Integrated Gas Unit Controller

L1

LS

— Line

— Limit Switch

LS1

— Limit Switch

MGV

— Main Gas Valve

LEGEND

NEC

— National Electrical Code

OFM

— Outdoor-Fan Motor

QT

RS

SW

— Quadruple Terminal

— Rollout Switch

SEN

— Sensor

— Switch

TRAN — Transformer

Field Splice

Terminal (Marked)

Terminal (Unmarked)

Splice

Splice (Marked)

Factory Wiring

Field Control Wiring

Field Power Wiring

Accessory or Optional Wiring

To Indicate Common Potential

Only, Not to Represent Wiring

NOTES:

1. If any of the original wires furnished are replaced, they must be replaced with type 90 degree C wire or its equivalent.

2. See price pages for thermostat and subbases.

3. Use 75 degree C copper conductors for field installation.

4. For high speed IFM, disconnect RED wire from IGC terminal BM and connect BLK wire from IFM. For medium speed, disconnect RED wire from IGC terminal BM and connect BLU wire from IFM.

Fig. 17 — 460-3-60 Wiring Diagram, Unit 48GS and 48GX

21

CHECKING AND ADJUSTING REFRIGERANT CHARGE

— The refrigerant system is fully charged with R-22 refrigerant, tested, and factory-sealed.

NOTE: Adjustment of the refrigerant charge is not required unless the unit is suspected of not having the proper R-22 charge.

A superheat charging chart is attached to the outside of the service access panel. The chart includes the required suction line temperature at given suction line pressures and outdoor ambient temperatures.

An accurate superheat, thermocouple- or thermistor-type thermometer, and a gage manifold are required when using the superheat charging method for evaluating the unit charge.

Do not use mercury or small dial-type thermometers because they are not adequate for this type of measurement.

When evaluating the refrigerant charge, an indicated adjustment to the specified factory charge must always be very minimal. If a substantial adjustment is indicated, an abnormal condition exists somewhere in the cooling system, such as insufficient airflow across either coil or both coils.

Proceed as follows:

1. Remove caps from low and high pressure 1 ⁄

4 in. Schrader service fittings.

2. Using hoses with valve core depressors, attach low and high pressure gage hoses to low and high pressure service fittings, respectively.

3. Start unit in Cooling mode and let unit run until system pressures stabilize.

4. Measure and record the following: a. Outdoor ambient-air temperature (F db).

b. Suction-tube temperature (F) at low-side service fitting.

c. Suction (low-side) pressure (psig).

5. Using ‘‘Cooling Charging Charts’’ compare outdoor-air temperature (F db) with the suction line pressure (psig) to determine desired system operating suction line temperature. See Fig. 18-30.

6. Compare actual suction-tube temperature with desired suction-tube temperature. Using a tolerance of ± 3° F, add refrigerant if actual temperature is more than 3° F higher than proper suction-tube temperature, or remove refrigerant if actual temperature is more than 3° F lower than required suction-tube temperature.

NOTE: If the problem causing the inaccurate readings is a refrigerant leak, refer to Check for Refrigerant Leaks section on page 15.

INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS

For cooling operation, the recommended airflow is

350 to 450 cfm for each 12,000 Btuh of rated cooling capacity. For heating operation, the airflow must produce a temperature rise that falls within the range stamped on the unit rating plate.

Table 7 shows the temperature rise at various airflow rates.

Tables 9 and 10 shows both heating and cooling airflows at various external static pressures. Refer to these tables to determine the airflow for the system being installed. See

Tables 11A and 11B for wet coil pressure drop.

NOTE: Be sure that all supply- and return-air grilles are open, free from obstructions, and adjusted properly.

Shut off gas supply then disconnect electrical power to the unit before changing blower speed. Electrical shock can cause personal injury or death.

Airflow can be changed by changing the lead connections of the blower motor.

Unit 48GS two- or three-speed motors (except size 030) are factory wired for low speed operation. Unit 48GS030 is factory wired for medium speed.

All 48GX units are factory wired for low speed and may need to be wired for medium or high speed in the field.

For 208/230-v Motors — The motor leads are color-coded as follows:

3-SPEED black = high speed blue = medium speed red = low speed

2-SPEED black = high speed red = low speed

To change the speed of the blower motor (BM), remove the fan motor speed leg lead from the blower relay (BR).

This wire is attached to IGC terminal BM for single-phase and 3-phase units. To change the speed, remove and replace with lead for desired blower motor speed. Insulate the re-

moved lead to avoid contact with chassis parts.

For 460-v GE Motors — The motor leads are color coded as follows:

3-SPEED black = high violet = jumper orange = medium red = low

To change the speed of the blower motor (BM), remove fan motor speed lead from the blower relay (BR) and replace with the lead for the desired blower motor speed. The motor speed lead is attached to terminal BM. For low and medium speeds black must be connected to the jumper wire.

Insulate removed lead end to avoid contact with chassis parts.

To select high speed on 460-v GE motors, separate the black female quick connect (QC) from the jumper lead male quick connect (QC) and connect the black lead to the BR. Insulate

the jumper to avoid contact with any chassis parts.

22

Fig. 18 — Cooling Charging Chart,

48GS018 Units

Fig. 20 — Cooling Charging Chart,

48GS030 Units

Fig. 19 — Cooling Charging Chart,

48GS024 Units

Fig. 21 — Cooling Charging Chart,

48GS036 Units

23

Fig. 22 — Cooling Charging Chart,

48GS042 Units

Fig. 23 — Cooling Charging Chart,

48GS048 Units

Fig. 24 — Cooling Charging Chart,

48GS060 Units

24

Fig. 25 — Cooling Charging Chart,

48GX024 Units

Fig. 27 — Cooling Charging Chart,

48GX036 Units

Fig. 26 — Cooling Charging Chart,

48GX030 Units

Fig. 28 — Cooling Charging Chart,

48GX042 Units

25

Fig. 29 — Cooling Charging Chart,

48GX048 Units

Fig. 30 — Cooling Charging Chart,

48GX060 Units

26

Table 9 — Dry Coil Air Delivery* — Horizontal and Downflow Discharge —

Unit 48GS018-060 (Deduct 10% for 208 Volts)

230 AND 460 VOLT

Unit

48GS

Motor

Speed

018

024

030

036

042

048

060

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

576

1430

680

1720

810

1800

—

—

—

—

—

—

—

1475

280

950

380

1220

485

1475

0.00

227

1082

—

—

287

1270

280

950

380

1220

485

—

—

—

—

—

1033

2105

1084

2318

—

—

0.1

212

1016

—

—

275

1179

275

880

375

1150

475

1440

275

880

375

1150

475

1440

566

1403

671

1630

800

1745

675

1454

886

1515

—

—

727

1678

853

1914

979

2150

949

2057

1054

2248

—

—

0.2

196

929

—

—

266

1054

270

825

365

1090

470

1350

270

825

365

1090

470

1350

556

1365

660

1538

790

1660

660

1387

855

1458

—

—

712

1639

836

1870

959

2100

864

2009

1024

2179

1184

2349

*Air delivery values are without air filter and are for dry coil. (See Table 11A — Wet Coil Pressure Drop table.)

NOTE: Deduct field-supplied air filter pressure drop and wet coil pressure drop to obtain external static pressure available for ducting.

1600

821

1825

943

2050

836

1943

994

2110

1152

2278

—

253

932

267

750

360

1025

460

0.3

177

796

—

External Static Pressure (in. wg)

0.4

0.5

0.6

165

668

—

153

428

—

—

—

—

—

242

780

264

670

355

970

455

—

234

633

262

580

350

860

445

—

226

372

260

400

344

760

437

512

1157

604

1346

766

1547

640

1275

1200

264

670

355

970

455

1200

795

1350

950

1488

688

538

1263

624

1439

782

1600

650

1326

1275

267

750

360

1025

460

1275

825

1406

1000

1551

700

1125

262

580

350

860

445

1125

497

1068

620

1267

742

1465

630

1204

778

1285

925

1424

666

481

973

602

1167

723

1360

620

1142

1025

260

400

344

760

437

1025

765

1224

910

1360

644

466

900

558

1126

709

1270

610

1081

750

1163

890

1296

622

925

—

—

335

620

430

925

0.7

—

—

—

—

—

—

—

—

335

620

430

1561

807

1780

927

2000

822

1909

971

2058

1120

2207

1500

782

1711

897

1922

808

1876

955

2000

1102

2124

1440

756

1642

868

1845

772

1823

928

1932

1084

2041

1379

730

1573

838

1767

737

1770

897

1885

1056

2000

450

827

534

1018

688

1163

595

995

735

1091

875

1233

595

750

—

—

312

450

415

750

0.8

—

—

—

—

—

—

—

—

312

450

415

1289

699

1470

802

1600

705

1698

867

1829

1029

1960

718

1013

855

1148

569

435

704

512

858

661

967

580

918

400

—

—

—

—

385

400

0.9

—

—

—

—

—

—

—

—

—

—

385

1198

667

1367

766

1535

674

1627

835

1740

997

1853

700

932

833

1071

—

—

—

496

781

627

876

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

1.0

—

—

—

—

640

1270

730

1419

642

1531

803

1638

965

1745

27

Table 10 — Dry Coil Air Delivery* — Horizontal and Downflow Discharge —

Unit 48GX024-060 (Deduct 10% for 208 Volts)

230 AND 460 VOLT

Unit

48GX

Motor

Speed

024

030

036

042

048

060

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Low

Med

High

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

Cfm

Watts

643

1626

—

—

—

—

614

1591

—

—

—

—

—

—

—

778

1854

—

—

834

2016

941

2379

—

—

0.00

281

899

—

—

—

—

246

982

343

1233

—

0.1

282

828

—

—

—

—

244

860

339

1170

—

—

470

1463

—

—

—

—

625

1614

—

—

—

—

588

1549

756

1837

—

—

813

1955

889

2233

—

—

0.2

281

757

—

—

—

—

243

808

336

1109

—

—

458

1406

514

1497

—

—

614

1579

—

—

—

—

577

1518

738

1804

—

—

782

1898

851

2124

960

2497

605

1532

—

—

—

—

572

1490

—

445

1344

501

1428

646

1491

969

—

—

241

736

332

1038

—

719

1759

—

—

746

1840

822

2038

949

2224

0.3

278

691

375

External Static Pressure (in. wg)

0.4

0.5

0.6

276

619

370

—

—

363

—

—

357

897

—

—

—

—

328

953

441

1202

430

1273

487

1348

636

1412

593

1478

726

1731

—

—

566

1460

699

1705

896

1956

712

1781

797

1964

920

2075

824

468

994

—

—

322

855

432

1111

415

1188

471

1255

626

1325

574

1421

695

1672

—

—

556

1421

676

1643

862

1879

680

1717

772

1892

883

1986

744

457

913

—

—

317

754

421

549

1361

661

1610

—

—

539

1372

1021

399

1091

455

1152

614

1228

650

1577

829

1797

652

1646

745

1814

845

1915

*Air delivery values are without air filter and are for dry coil. (See Table 11B — Wet Coil Pressure Drop table.)

NOTE: Deduct field-supplied air filter pressure drop and wet coil pressure drop to obtain external static pressure available for ducting.

0.7

—

—

352

649

444

826

—

—

—

—

410

623

1508

800

1709

626

1566

714

1727

812

1831

518

1295

625

1541

790

1699

517

1312

929

384

983

438

1042

602

1120

485

1218

591

1456

766

1602

491

1242

826

—

—

422

929

589

1003

596

1440

775

1615

—

—

679

1626

783

1721

0.8

—

—

—

—

431

730

—

—

—

—

400

454

1120

561

1345

742

1494

—

—

—

—

—

—

—

—

—

572

1375

752

1514

—

—

639

1511

753

1588

0.9

—

—

—

—

—

—

—

—

423

620

—

—

—

540

1193

713

1367

—

—

—

—

—

—

—

—

—

555

1315

728

1406

—

—

—

—

—

—

—

—

—

—

—

—

—

—

1.0

—

—

—

28

Table 11A — 48GS Wet Coil Pressure Drop

UNIT SIZE

48GS

018

024

030

036

042

048

060

AIRFLOW

(cfm)

500

600

700

700

800

900

900

1000

1100

1100

1200

1300

1300

1400

1500

1500

1600

1700

1900

2000

2100

PRESSURE DROP

(in. wg)

0.049

0.070

0.095

0.077

0.100

0.127

0.065

0.080

0.097

0.084

0.100

0.177

0.103

0.120

0.138

0.088

0.100

0.113

0.108

0.120

0.132

Table 11B — 48GX Wet Coil Pressure Drop

UNIT SIZE

48GX

024

030

036

042

048

060

1300

1300

1400

1500

1500

1600

1700

1900

2000

2100

AIRFLOW

(cfm)

700

800

900

900

1000

1100

1100

1200

PRESSURE DROP

(in. wg)

0.0535

0.067

0.123

0.0687

0.083

0.150

0.084

0.100

0.177

0.099

0.177

0.204

0.199

0.137

0.156

0.108

0.120

0.132

COOLING SEQUENCE OF OPERATION — With the room thermostat SYSTEM switch in the COOL position and the

FAN switch in the AUTO. position, the cooling sequence of operation is as follows:

When the room temperature rises to a point that is slightly above the cooling control setting of the thermostat, the thermostat completes the circuit between thermostat terminal R to terminals Y and G. These completed circuits through the thermostat connect contactor coil (C) (through unit wire Y) and blower relay coil (BR) (through unit wire G) across the

24-v secondary of transformer (TRAN).

The normally open contacts of energized contactor (C) close and complete the circuit through compressor motor (COMP) to condenser (outdoor) fan motor (OFM). Both motors start instantly.

The set of normally open contacts of energized relay BR close and complete the circuit through evaporator blower (indoor) fan motor (IFM).

29

NOTE: Once the compressor has started and then has stopped, it should not be started again until 5 minutes have elapsed.

The cooling cycle remains ‘‘on’’ until the room temperature drops to point that is slightly below the cooling control setting of the room thermostat. At this point, the thermostat

‘‘breaks’’ the circuit between thermostat terminal R to terminals Y and G. These open circuits deenergize contactor coil C and relay coil BR. The condenser and compressor motors stop. After a 30-second delay, the blower motor stops.

The unit is in a ‘‘standby’’ condition, waiting for the next

‘‘call for cooling’’ from the room thermostat.

MAINTENANCE

To ensure continuing high performance, and to minimize the possibility of premature equipment failure, periodic maintenance must be performed on this equipment. This combination heating/cooling unit should be inspected at least once each year by a qualified service person. To troubleshoot heating or cooling of units, refer to tables at the back of the book.

NOTE TO EQUIPMENT OWNER: Consult your local dealer about the availability of a maintenance contract.

The ability to properly perform maintenance on this equipment requires certain expertise, mechanical skills, tools, and equipment. If you do not possess these, do not attempt to perform any maintenance on this equipment other than those procedures recommended in the User’s Manual. FAILURE TO HEED THIS WARN-

ING COULD RESULT IN SERIOUS PERSONAL

INJURY AND POSSIBLE DAMAGE TO THIS

EQUIPMENT.

Failure to follow these warnings could result in serious personal injury:

1. Turn off gas supply, then turn off electrical power to the unit before performing any maintenance or service on the unit.

2. Use extreme caution when removing panels and parts.

As with any mechanical equipment, personal injury can result from sharp edges, etc.

3. Never place anything combustible either on, or in contact with, the unit.

4. Should overheating occur, or the gas supply fail to shut off, shut off the external main manual gas valve to the unit, then shut off the electrical supply.

Errors made when reconnecting wires may cause improper and dangerous operation. Label all wires prior to disconnection when servicing.

The minimum maintenance requirements for this equipment are as follows:

1. Inspect air filter(s) each month. Clean or replace when necessary. Certain geographical locations may require more frequent inspections.

2. Inspect indoor coil, outdoor coil, drain pan, and condensate drain each cooling season for cleanliness. Clean when necessary.

3. Inspect blower motor and wheel for cleanliness each heating and cooling season. Clean when necessary. For first heating and cooling season, inspect blower wheel bimonthly to determine proper cleaning frequency.

4. Check electrical connections for tightness and controls for proper operation each heating and cooling season. Service when necessary.

5. Check and inspect heating section before each heating season. Clean and adjust when necessary.

6. Check flue hood and remove any obstructions if necessary.

Air Filter

Never operate the unit without a suitable air filter in the return-air duct system. Always replace the filter with the same dimensional size and type as originally installed.

See Tables 1 and 2 for recommended filter sizes.

Inspect air filter(s) at least once each month and replace

(throwaway-type) or clean (cleanable-type) at least twice during each heating and cooling season or whenever the filter(s) becomes clogged with dust and lint.

Evaporator Blower and Motor

NOTE: All motors are prelubricated. Do not attempt to lubricate these motors.

For longer life, operating economy, and continuing efficiency, clean accumulated dirt and grease from the blower wheel and motor annually.

Turn off the gas supply, then disconnect and tag electrical power to the unit before cleaning the blower motor and wheel. Failure to adhere to this warning could cause personal injury or death.

To clean the blower motor and wheel:

1. Remove and disassemble blower assembly as follows: a. Remove unit access panel.

b. Disconnect motor lead from blower relay (BR).

Disconnect yellow lead from terminal L2 of the contactor.

c. On all units remove blower assembly from unit. Remove screws securing blower to blower partition and slide assembly out. Be careful not to tear insulation in blower compartment.

d. Ensure proper reassembly by marking blower wheel and motor in relation to blower housing before disassembly.

e. Loosen setscrew(s) that secures wheel to motor shaft, remove screws that secure motor mount brackets to housing, and slide motor and motor mount out of housing.

2. Remove and clean blower wheel as follows: a. Ensure proper reassembly by marking wheel orientation.

b. Lift wheel from housing. When handling and/or cleaning blower wheel, be sure not to disturb balance weights

(clips) on blower wheel vanes.

c. Remove caked-on dirt from wheel and housing with a brush. Remove lint and/or dirt accumulations from wheel and housing with vacuum cleaner, using soft brush attachment. Remove grease and oil with mild solvent.

d. Reassemble wheel into housing.

e. Reassemble motor into housing. Be sure setscrews are tightened on motor shaft flats and not on round part of shaft.

f. Reinstall unit access panel.

3. Restore electrical power, then gas supply to unit. Start unit and check for proper blower rotation and motor speeds during heating and cooling cycles.

Flue Gas Passageways —

To inspect the flue collector box and upper areas of the heat exchanger:

1. Remove the combustion blower wheel and motor assembly according to directions in Combustion-Air Blower section below.

2. Remove the 3 screws holding the blower housing to the flue collector box cover (see Fig. 31).

3. Remove the 12 screws holding the flue collector box cover

(Fig. 31) to the heat exchanger assembly. Inspect the heat exchangers.

4. Clean all surfaces as required using the wire brush.

Fig. 31 — Blower Housing and Flue

Collector Box

Combustion-Air Blower —

Clean periodically to assure proper airflow and heating efficiency. Inspect blower wheel every fall and periodically during heating season. For the first heating season, inspect blower wheel bimonthly to determine proper cleaning frequency.

To inspect blower wheel, remove draft hood assembly. Shine a flashlight into opening to inspect wheel. If cleaning is required, remove motor and wheel as follows:

1. Remove unit access panel. (See Fig. 32.)

2. Remove the 7 screws that attach induced-draft motor mounting plate to blower housing. (See Fig. 31.)

3. Slide the motor and blower wheel assembly out of the blower housing. (See Fig. 33.) Clean the blower wheel.

If additional cleaning is required, continue with Steps 4 and 5.

4. To remove blower, remove 2 setscrews. (See Fig. 33.)

5. To remove motor and cooling fan assembly, remove

4 screws that hold blower housing to mounting plate.

6. To reinstall, reverse the procedure outlined above.

Limit Switch —

Remove unit access panel. Limit switch is located on the blower partition.

30

Fig. 32 — Unit Access Panel

BLOWER

HOUSING

When servicing gas train, do not hit or plug orifice spuds.

REMOVAL OF GAS TRAIN

1. Shut off manual gas valve.

2. Shut off power to unit.

3. Remove unit access panel. (See Fig. 32.)

4. Disconnect gas piping at unit gas valve.

5. Remove wires connected to gas valve. Mark each wire.

6. Remove ignitor and sensor wires at the ignitor module.

7. Remove the mounting screw that attaches the burner rack to the basepan. (See Fig. 31.)

8. Slide the burner rack out of the unit. (See Fig. 31 and 34.)

9. To reinstall, reverse the procedure outlined above.

2 SETSCREWS

(HIDDEN)

Fig. 33 — Removal of Motor and Blower Wheel

Burner Ignition —

Unit is equipped with a direct spark ignition 100% lockout system. Ignition module is located in the control box. Module contains a self-diagnostic

LED. During servicing, refer to label diagram for LED interpretation.

If lockout occurs, unit may be reset by either momentarily interrupting power supply to unit, or turning selector switch to OFF position at the thermostat.

Main Burners —

At the beginning of each heating season, inspect for deterioration or blockage due to corrosion or other causes. Observe the main burner flames and adjust if necessary.

Fig. 34 — Burner Rack Removed

Condenser Coil, Evaporator Coil, and Condensate Drain Pan —

Inspect the condenser coil, evaporator coil, and condensate drain pan at least once each year.

The coils are easily cleaned when dry; therefore, inspect and clean the coils either before or after each cooling season. Remove all obstructions, including weeds and shrubs, that interfere with the airflow through the condenser coil.

31

Straighten bent fins with a fin comb. If coated with dirt or lint, clean the coils with a vacuum cleaner, using the soft brush attachment. Be careful not to bend the fins. If coated with oil or grease, clean the coils with a mild detergent-andwater solution. Rinse coils with clear water, using a garden hose. Be careful not to splash water on motors, insulation, wiring, or air filter(s). For best results, spray condenser coil fins from inside to outside the unit. On units with an outer and inner condenser coil, be sure to clean between the coils.

Be sure to flush all dirt and debris from the unit base.

Inspect the drain pan and condensate drain line when inspecting the coils. Clean the drain pan and condensate drain by removing all foreign matter from the pan. Flush the pan and drain tube with clear water. Do not splash water on the insulation, motor, wiring, or air filter(s). If the drain tube is restricted, clear it with a ‘‘plumbers snake’’ or similar probe device. Ensure that the auxiliary drain port above the drain tube is also clear.

Condenser Fan

Keep the condenser fan free from all obstructions to ensure proper cooling operation. Never place articles on top of the unit. Damage to unit may result.

1. Remove 6 screws holding condenser grille and motor to top cover.

2. Turn motor/grille assembly upside down on top cover to expose the fan blade.

3. Inspect the fan blades for cracks or bends.

4. If fan needs to be removed, loosen the setscrew and slide the fan off the motor shaft.

5. When replacing fan blade, position blade so that the hub is

1

⁄

8 in. away from the motor end (

1

⁄

8 in. of motor shaft will be visible). See Fig. 12.

6. Ensure that setscrew engages the flat area on the motor shaft when tightening.

7. Replace grille.

Electrical Controls and Wiring —

Inspect and check the electrical controls and wiring annually. Be sure to turn

off the gas supply, and then the electrical power to the unit.

Remove access panel to locate all the electrical controls and wiring. Check all electrical connections for tightness.

Tighten all screw connections. If any smoky or burned connections are noticed, disassemble the connection, clean all the parts, restrip the wire end and reassemble the connection properly and securely.

After inspecting the electrical controls and wiring, replace the access panel. Start the unit, and observe at least one complete heating cycle and one complete cooling cycle to ensure proper operation. If discrepancies are observed in either or both operating cycles, or if a suspected malfunction has occurred, check each electrical component with the proper electrical instrumentation. Refer to the unit wiring label when making these checkouts.

NOTE: Refer to the heating and/or cooling sequence of operation in this publication as an aid in determining proper control operation.

Refrigerant Circuit —

Inspect all refrigerant tubing connections and the unit base for oil accumulations annually.

Detecting oil generally indicates a refrigerant leak.

If oil is detected or if low cooling performance is suspected, leak-test all refrigerant tubing using an electronic leakdetector, halide torch, or liquid-soap solution. If a refrigerant leak is detected, refer to Check for Refrigerant Leaks section on page 15.

If no refrigerant leaks are found and low cooling performance is suspected, refer to Checking and Adjusting Refrigerant Charge section on page 22.

Gas Input —

The gas input does not require checking unless improper heating performance is suspected. If a problem exists, refer to Start-Up section on page 15.

Evaporator Airflow —

The heating and/or cooling airflow does not require checking unless improper performance is suspected. If a problem exists, be sure that all

supply- and return-air grilles are open and free from

obstructions, and that the air filter is clean. When necessary, refer to Indoor Airflow and Airflow Adjustments section on page 22 to check the system airflow.

Metering Device — Acutrol™ Device —

This metering device is a fixed orifice and is located in the header to the evaporator coil.

Liquid Line Strainer —

The liquid line strainer (to protect metering device) is made of wire mesh and located in the liquid line on the inlet side of the metering device.

32

SYMPTOM

Compressor and condenser fan will not start.

Compressor will not start but condenser fan runs.

TROUBLESHOOTING

Cooling

CAUSE

Power failure

Fuse blown or circuit breaker tripped

Defective thermostat, contactor, transformer, or control relay

Insufficient line voltage

Incorrect or faulty wiring

Thermostat setting too high

Faulty wiring or loose connections in compressor circuit

Compressor motor burned out, seized, or internal overload open

Defective run/start capacitor, overload, start relay

One leg of 3-phase power dead

Scroll compressor is rotating in the wrong direction

REMEDY

Call power company.

Replace fuse or reset circuit breaker.

Replace component.

Determine cause and correct.

Check wiring diagram and rewire correctly.

Lower thermostat setting below room temperature.

Check wiring and repair or replace.

Determine cause. Replace compressor.

Determine cause and replace.

Replace fuse or reset circuit breaker.

Determine cause.

Correct the direction of rotation by reversing the

3-phase power leads to the unit. Shut down unit to allow pressures to equalize.

Three-phase scroll compressor (48GS048 and 48GX030-060 only) makes excessive noise, and there may be a low pressure differential.

Compressor cycles

(other than normally satisfying thermostat).

Compressor operates continuously.

Excessive head pressure.

Head pressure too low.

Excessive suction pressure.

Suction pressure too low.

Refrigerant overcharge or undercharge

Defective compressor

Insufficient line voltage

Blocked condenser

Defective run/start capacitor, overload or start relay

Defective thermostat

Faulty condenser-fan motor or capacitor

Restriction in refrigerant system

Dirty air filter

Unit undersized for load

Thermostat set too low

Low refrigerant charge

Leaking valves in compressor

Air in system

Condenser coil dirty or restricted

Dirty air filter

Dirty condenser coil

Refrigerant overcharged

Air in system

Condenser air restricted or air short-cycling

Low refrigerant charge

Compressor valves leaking

Restriction in liquid tube

High heat load

Compressor valves leaking

Refrigerant overcharged

Dirty air filter

Low refrigerant charge

Metering device or low side restricted

Insufficient evaporator airflow

Temperature too low in conditioned area

Outdoor ambient below 40 F

Field-installed filter-drier restricted

Recover refrigerant, evacuate system, and recharge to capacities shown on nameplate.

Replace and determine cause.

Determine cause and correct.

Determine cause and correct.

Determine cause and replace.

Replace thermostat.

Replace.

Locate restriction and remove.

Replace filter.

Decrease load or increase unit size.

Reset thermostat.

Locate leak, repair, and recharge.

Replace compressor.

Recover refrigerant, evacuate system, and recharge.

Clean coil or remove restriction.

Replace filter.

Clean coil.

Recover excess refrigerant.

Recover refrigerant, evacuate system, and recharge.

Determine cause and correct.

Check for leaks, repair and recharge.

Replace compressor.

Remove restriction.

Check for source and eliminate.

Replace compressor.

Recover excess refrigerant.

Replace filter.

Check for leaks, repair and recharge.

Remove source of restriction.

Increase air quantity. Check filter — replace if necessary.

Reset thermostat.

Install low-ambient kit.

Replace.

33

SYMPTOM

Burners will not ignite.

Inadequate heating.

Poor flame characteristics.

CAUSE

Water in gas line

No power to furnace

No 24-v power supply to control circuit

Heating

Miswired or loose connections

Burned-out heat anticipator in thermostat

Broken thermostat wire

Misaligned spark electrodes

No gas at main burners

Dirty air filter

Gas input to furnace too low

Unit undersized for application

Restricted airflow

Blower speed too low

Limit switch cycles main burners

Incomplete combustion results in:

Aldehyde odors, carbon monoxide, sooting flame, floating flame

REMEDY

Drain. Install drip leg.

Check power supply fuses, wiring, or circuit breaker.

Check transformer.

NOTE: Some transformers have internal overcurrent protection that requires a cool-down period to reset.

Check all wiring and wirenut connections.

Replace thermostat.

Run continuity check. Replace wire if necessary.

Check flame ignition and sense electrode positioning.

Adjust as necessary.

1. Check gas line for air. Purge as necessary.

NOTE: After purging gas line of air, wait at least

5 minutes for any gas to dissipate before attempting to light unit.

2. Check gas valve.

Clean or replace filter as necessary.

Check gas pressure at manifold. Match with that on unit nameplate.

Replace with proper unit or add additional unit.

Clean or replace filter. Remove any restriction.

Use faster speed tap if available, or install alternate motor.

Check rotation of blower, thermostat heat anticipator settings, temperature rise of unit. Adjust as necessary.

1. Tighten all screws around burner compartment.

2. Cracked heat exchanger. Replace.

3. Unit overfired. Reduce input (change orifices or adjust gas line or manifold pressure).

4. Check burner alignment.

SYMPTOM

Hardware failure.

(LED OFF)

Fan ON/OFF delay modified (LED/

FLASH)

Limit switch fault.

(LED 2 flashes)

Flame sense fault.

(LED 3 flashes)

4 consecutive limit switch faults.

(LED 4 flashes)

Ignition lockout.

(LED 5 flashes)

Induced-draft motor fault.

(LED 6 flashes)

Rollout switch fault.

(LED 7 flashes)

Internal control fault.

(LED 8 flashes)

LED Troubleshooting — Error Code

CAUSE

Loss of power to control module (IGC).

REMEDY

Check 5 amp fuse on IGC, power to unit, 24-v circuit breaker, and transformer. Units without a 24-v circuit breaker have an internal overload in the 24-v transformer. If the overload trips, allow 10 minutes for automatic reset.

Ensure unit is fired on rate and temperature rise is correct.

High limit switch opens during heat exchanger warm-up period before fan-on delay expires.

Limit switch opens within three minutes after blower-off delay timing in Heating mode.

High temperature limit switch is open.

The IGC sensed flame that should not be present.

Inadequate airflow to unit.

Unit unsuccessfully attempted ignition for

15 minutes.

IGC does not sense that induced-draft motor is operating.

Rollout switch has opened.

Microprocessor has sensed an error in the software or hardware.

Ensure unit’s external static pressure is within application guidelines.

Check the operation of the indoor (evaporator) fan motor. Ensure that the supply-air temperature rise is in accordance with the range on the unit nameplate.

Reset unit. If problem persists, replace control board.

Check operation of indoor (evaporator) fan motor and that supply-air temperature rise agrees with range on unit nameplate information.

Check ignitor and flame sensor electrode spacing, gaps, etc. Ensure that flame sense and ignition wires are properly terminated. Verify that unit is obtaining proper amount of gas.

Check for proper voltage. If motor is operating, check the speed sensor plug/IGC Terminal J2 connection. Proper connection: PIN 1

— White, PIN 2 — Red, PIN 3 — Black.

Rollout switch will automatically reset, but IGC will continue to lockout unit. Check gas valve operation. Ensure that induced-draft blower wheel is properly secured to motor shaft. Reset unit at unit disconnect.

If error code is not cleared by resetting unit power, replace the IGC.

If the IGC must be replaced, be sure to ground yourself to dissipate any electrical charge that may be present before handling new control board. The IGC is sensitive to static electricity and may be damaged if the necessary precautions are not taken.

IMPORTANT: Refer to Heating troubleshooting chart for additional troubleshooting analysis.

LEGEND

IGC

— Integrated Gas Unit Controller

LED — Light-Emitting Diode

Copyright 1999 Carrier Corporation

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

Book 1 4

Tab 1a 6a

PC 111 Catalog No. 534-732 Printed in U.S.A.

Form 48GS,GX-1SI Pg 34 1-99 Replaces: 48GS-1SI

I. PRELIMINARY INFORMATION

MODEL NO.:

DATE:

START-UP CHECKLIST

(Remove and Store in Job File)

SERIAL NO.:

TECHNICIAN:

II. PRE-START-UP (insert checkmark in box as each item is completed)

M VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT

M VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTALLATION INSTRUCTIONS

M CHECK ALL ELECTRICAL CONNECTIONS AND TERMINALS FOR TIGHTNESS

M CHECK GAS PIPING FOR LEAKS

M CHECK THAT INDOOR (EVAPORATOR) AIR FILTER IS CLEAN AND IN PLACE

M VERIFY THAT UNIT INSTALLATION IS LEVEL

M CHECK FAN WHEEL AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE AND SETSCREW

TIGHTNESS

III. START-UP

ELECTRICAL

SUPPLY VOLTAGE L1-L2

COMPRESSOR AMPS L1

COMPRESSOR AMPS L1

INDOOR (EVAPORATOR) FAN AMPS

L2-L3

L2

L2

L3-L1

L3

L3

TEMPERATURES

OUTDOOR (CONDENSER) AIR TEMPERATURE

RETURN-AIR TEMPERATURE

COOLING SUPPLY AIR

GAS HEAT SUPPLY AIR

DB

DB

DB

WB

WB

PRESSURES

GAS INLET PRESSURE

GAS MANIFOLD PRESSURE

REFRIGERANT SUCTION

REFRIGERANT DISCHARGE

IN. WG

IN. WG

PSIG

PSIG

SUCTION LINE TEMP*

DISCHARGE TEMP†

M VERIFY REFRIGERANT CHARGE USING CHARGING TABLES

M VERIFY THAT 3-PHASE SCROLL COMPRESSOR (48GS048 AND 48GX030-060) IS ROTATING IN

CORRECT DIRECTION

*Measured at suction inlet to compressor.

†Measured at liquid line leaving condenser.

Copyright 1999 Carrier Corporation

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

Book 1 4

Tab 1a 6a

PC 111 Catalog No. 534-732 Printed in U.S.A.

Form 48GS,GX-1SI Pg CL-1 1-99 Replaces: 48GS-1SI