User manual | Installation, Start-Up and Service Instructions CONTENTS

48TJ016-028
Single Package Rooftop Units
Electric Cooling/Gas Heating
Installation, Start-Up and
Service Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
Step 1 — Provide Unit Support . . . . . . . . . . . . . . . 1
• ROOF CURB
• ALTERNATE UNIT SUPPORT
Step 2 — Rig and Place Unit . . . . . . . . . . . . . . . . . . 3
• POSITIONING
• ROOF MOUNT
Step 3 — Field Fabricate Ductwork . . . . . . . . . . . . 9
Step 4 — Make Unit Duct Connections . . . . . . . . 9
Step 5 — Install Flue Hood . . . . . . . . . . . . . . . . . . . 9
Step 6 — Trap Condensate Drain . . . . . . . . . . . . 10
Step 7 — Install Gas Piping . . . . . . . . . . . . . . . . . . 10
Step 8 — Make Electrical Connections . . . . . . . 10
• FIELD POWER SUPPLY
• FIELD CONTROL WIRING
Step 9 — Make Outdoor-Air Inlet
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
• MANUAL OUTDOOR-AIR DAMPER
• OPTIONAL ECONOMIZER
Step 10 — Install Outdoor-Air Hood . . . . . . . . . . 13
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-19
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19-28
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . CL-1
1. Improper installation, adjustment, alteration, service, or maintenance can cause property damage, personal injury, or loss of life. Refer to the User’s
Information Manual provided with this unit for more
details.
2. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other
appliance.
What to do if you smell gas:
1. DO NOT try to light any appliance.
2. DO NOT touch any electrical switch, or use any phone
in your building.
3. IMMEDIATELY call your gas supplier from a neighbor’s phone. Follow the gas supplier’s instructions.
4. If you cannot reach your gas supplier, call the fire
department.
Disconnect gas piping from unit when pressure testing
at pressure greater than 0.5 psig. Pressures greater than
0.5 psig will cause gas valve damage resulting in hazardous condition. If gas valve is subjected to pressure
greater than 0.5 psig, it must be replaced before use. When
pressure testing field-supplied gas piping at pressures of
0.5 psig or less, a unit connected to such piping must be
isolated by closing the manual gas valve(s).
SAFETY CONSIDERATIONS
Installation and servicing of air-conditioning equipment
can be hazardous due to system pressure and electrical components. Only trained and qualified service personnel should
install, repair, or service air-conditioning equipment.
Untrained personnel can perform the basic maintenance
functions of cleaning coils and filters and replacing filters.
All other operations should be performed by trained service
personnel. When working on air-conditioning equipment, observe precautions in the literature, tags and labels attached
to the unit, and other safety precautions that may apply.
Follow all safety codes. Wear safety glasses and work gloves.
Use quenching cloth for unbrazing operations. Have fire extinguishers available for all brazing operations.
Before performing service or maintenance operations on
unit, turn off main power switch to unit. Electrical shock
could cause personal injury.
INSTALLATION
Step 1 — Provide Unit Support
When handling 48TJE024 and 028 units with a forklift
truck, use a minimum of 48-in. long forks and lift ONLY
through factory-provided holes in base rail. Otherwise,
damage to the unit may result.
ROOF CURB — Assemble or install accessory roof curb or
horizontal adapter in accordance with instructions shipped
with this accessory. See Fig. 1 and 2. Install insulation, cant
strips, roofing, and counter flashing as shown. Ductwork can
be installed to roof curb or horizontal adapter before unit is
set in place. Curb or adapter should be level. This is necessary to permit unit drain to function properly. Unit leveling tolerance is ± 1⁄16 in. per linear ft in any direction. Refer
to Accessory Roof Curb or Horizontal Adapter Installation
Instructions for additional information as required. When accessory roof curb or horizontal adapter is used, unit may be
installed on class A, B, or C roof covering material.
Instructions continued on page 3.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 111
Catalog No. 564-873
Printed in U.S.A.
Form 48TJ-11SI
Pg 1
4-96
Replaces: 48TJ-7SI
Tab 1a 6a
NOTE: To prevent the hazard of stagnant water build-up in the drain
pan of the indoor-air section, unit can only be pitched as shown.
LEGEND
COMPR SECT. — Compressor Section
NOTES:
1. Roof curb accessory is shipped unassembled.
2. Insulated panels, 1⁄2-in. thick neoprene-coated, 2 lb density.
3. Dimensions in ( ) are in millimeters.
4.
Direction of airflow.
5. Roof curb: 18 gage steel.
6. Attach all ductwork to roof curb.
7. Field installation of sidewall is mandatory.
ACCESSORY
PACKAGE
NO.
CURB
HEIGHT
50PQ900221
18-29
(355)
50PQ900141
28-09
(610)
50PQ900151
50DP900211
48DP900041*
48DP900051*
48DP900061*
48DP900071*
28-09
(610)
18-119
(584)
18-29
(355)
28-09
(610)
28-09
(610)
18-119
(584)
DESCRIPTION
‘‘A’’
‘‘B’’
‘‘C’’
‘‘D’’
‘‘E’’
Standard Curb —
149 High
Standard Curb for
Units Requiring
High Installation
Horizontal Supply and
Return Curb
Pre-Assembled, High-Static,
Horizontal Adapter
Standard Curb —
149 High
Standard Curb
for Units Requiring
High Installation
Horizontal Supply
and Return Curb
Pre-Assembled, High-Static,
Horizontal Adapter
58-71⁄169
(1703)
18-713⁄169
(503)
—
—
—
58-7 ⁄ 9
(1703)
18-7 ⁄ 9
(503)
—
—
—
58-7 ⁄ 9
(1703)
58-71⁄169
(1703)
78-213⁄169
(2205)
18-7 ⁄ 9
(503)
18-713⁄169
(503)
38-35⁄89
(1006)
58-69
(1676)
68-29
(1880)
08-2 ⁄ 9
(64)
08-61⁄49
(159)
18-69
(457)
18-25⁄89
(371)
—
—
—
78-213⁄169
(2205)
38-35⁄89
(1006)
—
—
—
78-213⁄169
(2205)
78-213⁄169
(2205)
38-35⁄89
(1006)
38-35⁄89
(1006)
58-69
(1676)
68-29
(1880)
08-21⁄29
(64)
08-61⁄49
(159)
18-69
(457)
18-25⁄89
(371)
1 16
1 16
13 16
*For high-heat applications.
Fig. 1 — Roof Curb Details
2
13 16
12
POSITIONING — Maintain clearance, per Fig. 4-6, around
and above unit to provide minimum distance from combustible materials, proper airflow, and service access.
Do not install unit in an indoor location. Do not locate
unit air inlets near exhaust vents or other sources of contaminated air. For proper unit operation, adequate combustion and ventilation air must be provided in accordance with
Section 5.3 (Air for Combustion and Ventilation) of the
National Fuel Gas Code, ANSI Z223.1 (American National
Standards Institute).
Although unit is weatherproof, guard against water from
higher level runoff and overhangs.
Locate mechanical draft system flue assembly at least
4 ft from any opening through which combustion products
could enter the building, and at least 4 ft from any adjacent
building. When unit is located adjacent to public walkways,
flue assembly must be at least 7 ft above grade.
ROOF MOUNT — Check building codes for weight distribution requirements. Unit operating weight is shown in
Table 1.
Instructions continued on page 9.
IMPORTANT: The gasketing of the unit to the roof
curb or adapter is critical for a watertight seal. Install
gasket with the roof curb or adapter as shown in
Fig. 1. Improperly applied gasket can also result in air
leaks and poor unit performance.
ALTERNATE UNIT SUPPORT — When a curb or adapter
cannot be used, install unit on a noncombustible surface. Support unit with sleepers, using unit curb support area. If sleepers cannot be used, support long sides of unit with a minimum of 3 equally spaced 4-in. x 4-in. pads on each side.
Step 2 — Rig and Place Unit — Inspect unit for transportation damage. File any claim with transportation agency.
Do not drop unit; keep upright. Use spreader bars over
unit to prevent sling or cable damage. Rollers may be used
to move unit across a roof. Level by using unit frame as a
reference; leveling tolerance is ± 1⁄16 in. per linear ft in any
direction. See Fig. 3 for additional information. Unit operating weight is shown in Table 1.
Four lifting holes are provided in ends of unit base rails
as shown in Fig. 3. Refer to rigging instructions on unit.
NOTE: For preassembled horizontal adapter part no. 50DP900211 and
48DP900071, the accessory kit includes a factory-designed, high-static, regain
transition duct. For horizontal curb part no. 50PQ900151 and 48DP900061, a
field-supplied transition duct is required.
Fig. 2 — Horizontal Adapters and Roof Curbs
UNIT
48TJ
D016
D020
D024
D028
E016
E024
E028
DIMENSIONS
MAXIMUM SHIPPING
WEIGHT
Lb
1800
2300
2350
2400
1800
2550
2600
Kg
816
1043
1066
1089
816
1156
1179
NOTES:
1. Dimensions in ( ) are in millimeters.
2. Refer to Table 1 for unit operating weights.
3. Remove boards at ends of unit and runners prior to rigging.
4. Rig by inserting hooks into unit base rails as shown. Use corner post from
packaging to protect coil from damage. Use bumper boards for spreader
bars on all units except 48TJE024 and 028.
5. Weights do not include optional economizer. See Table 1 for economizer
weight.
6. Weights given are for aluminum evaporator and condenser coil plate fins.
Weights of other metal combinations are listed in Table 1.
A
Ft-in.
6-111⁄2
6-111⁄2
6-111⁄2
6-111⁄2
6-111⁄2
8- 71⁄4
8- 71⁄4
B
mm
2121
2121
2121
2121
2121
2623
2623
Ft-in.
4-0
3-2
3-4
3-4
4-0
4-2
4-2
mm
1219
964
1016
1016
1219
1270
1270
All panels must be in place when rigging.
Fig. 3 — Rigging Details
3
UNIT
48TJ
X
Ft-in. mm
D016 3-2
965
D020 3-7 1090
E016 3-2
965
UNIT
48TJ
D016
D020
E016
A
Lb
384
520
383
Kg
174
235
174
DIMENSIONS
Y
Ft-in. mm
4-0 1219
3-2
965
4-0 1219
CORNER
B
Lb
Kg
370 168
508 230
369 167
WEIGHT*
C
Lb
Kg
358 162
486 220
360 163
Z
Ft-in.
1-10
1- 8
1-10
mm
559
508
559
D
Lb
538
636
538
Kg
244
288
244
*Weights are for unit only (aluminum plate fins) and do not include options or crating.
NOTES:
1. Dimensions in (
2.
3.
) are in millimeters.
Center of gravity.
Direction of airflow.
4. Ductwork to be attached to accessory roof curb or adapter
only.
5. Minimum clearance:
a. Rear: 7809 (2134) for coil removal. This dimension can
be reduced to 4809 (1219) if conditions permit coil removal from the top.
b. Left side: 4809 (1219) for proper condenser coil airflow.
c. Front: 4809 (1219) for control box access.
d. Right side: 4809 (1219) for proper operation of damper
and power exhaust (if so equipped).
e. Top: 6809 (1829) to assure proper condenser fan
operation.
f. Local codes or jurisdiction may prevail.
6. With the exception of clearance for the condenser coil and
the damper/power exhaust as stated in Note No. 5, a removable fence or barricade requires no clearance.
7. Dimensions are from outside of corner post. Allow 08-5⁄169
(8) on each side for top panel drip edge.
Fig. 4 — Base Unit Dimensions; 48TJ016,020
4
NOTES:
1. Dimensions in (
2.
3.
UNIT
48TJD
024
028
CORNER
B
Lb Kg Lb Kg
520 235 508 230
527 239 545 247
A
WEIGHT*
DIMENSION X
C
D
Lb Kg Lb Kg Ft-in.
mm
532 241 640 290
3-2
965
578 262 600 272
3-7
1092
) are in millimeters.
Center of gravity.
Direction of airflow.
4. Ductwork to be attached to accessory roof curb or adapter
only.
5. Minimum clearance:
a. Rear: 7809 (2134) for coil removal. This dimension can
be reduced to 4809 (1219) if conditions permit coil removal from the top.
b. 4809 (1219) to combustible surfaces, all four sides (includes between units).
c. Left side: 4809 (1219) for proper condenser coil airflow.
d. Front: 4809 (1219) for control box access.
e. Right side: 4809 (1219) for proper operation of damper
and power exhaust (if so equipped).
f. Top: 6809 (1829) to assure proper condenser fan
operation.
g. Bottom: 14 (356) to combustible surfaces (when not using curb or adapter).
h. Control box side: 3809 (914) to ungrounded surfaces (noncombustible).
i. Control box side, 3869 (1067) to block or concrete walls,
or other grounded surfaces.
j. Local codes or jurisdiction may prevail.
6. With the exception of clearance for the condenser coil and
the damper/power exhaust as stated in Note No. 5, a removable fence or barricade requires no clearance.
7. Dimensions are from outside of corner post. Allow 08-5⁄169
(8) on each side for top panel drip edge.
Fig. 5 — Base Unit Dimensions; 48TJD024,028
5
NOTES:
1. Dimensions in (
2.
3.
UNIT
48TJE
024
028
CORNER
B
Lb Kg Lb Kg
465 211 456 206
472 214 494 224
A
) are in millimeters.
Center of gravity.
Direction of airflow.
4. Ductwork to be attached to accessory roof curb or adapter
only.
5. Minimum clearance:
a. Rear: 7809 (2134) for coil removal. This dimension can
be reduced to 4809 (1219) if conditions permit coil removal from the top.
b. 4809 (1219) to combustible surfaces, all four sides (includes between units).
c. Left side: 4809 (1219) for proper condenser coil airflow.
d. Front: 4809 (1219) for control box access.
e. Right side: 4809 (1219) for proper operation of damper
and power exhaust (if so equipped).
f. Top: 6809 (1829) to assure proper condenser fan
operation.
g. Bottom: 14 (356) to combustible surfaces (when not using curb or adapter).
h. Control box side: 3809 (914) to ungrounded surfaces (noncombustible).
i. Control box side, 3869 (1067) to block or concrete walls,
or other grounded surfaces.
j. Local codes or jurisdiction may prevail.
6. With the exception of clearance for the condenser coil and
the damper/power exhaust as stated in Note No. 5, a removable fence or barricade requires no clearance.
7. Dimensions are from outside of corner post. Allow 08-5⁄169
(8) on each side for top panel drip edge.
WEIGHT*
DIMENSION X
C
D
Lb Kg Lb Kg Ft-in.
mm
644 292 835 378
3-4
1016
736 334 748 339
3-5
1041
*Weights are for unit only (aluminum plate fins) and do not include options
or crating.
Fig. 6 — Base Unit Dimensions; 48TJE024,028
6
Table 1 — Physical Data
UNIT SIZE
NOMINAL CAPACITY (tons)
OPERATING WEIGHT (lb)
Unit
Al/Al*
Al/Cu*
Cu/Cu*
Economizer
Roof Curb†
COMPRESSOR
Quantity
Oil (oz)
REFRIGERANT TYPE
Expansion Device
Operating Charge (lb-oz)
Circuit 1**
Circuit 2
CONDENSER COIL
Rows...Fins/in.
Total Face Area (sq ft)
CONDENSER FAN
Nominal Cfm
Quantity...Diameter (in.)
Motor Hp...Rpm
Watts Input (Total)
EVAPORATOR COIL
Rows...Fins/in.
Total Face Area (sq ft)
EVAPORATOR FAN
Quantity...Size (in.)
Type Drive
Nominal Cfm
Motor Hp
Maximum Continuous Bhp
Motor Frame Size
Nominal Rpm High/Low
Fan Rpm Range
Motor Bearing Type
Maximum Allowable Rpm
Motor Pulley Pitch Diameter Min/Max (in.)
Nominal Motor Shaft Diameter (in.)
Fan Pulley Pitch Diameter (in.)
Nominal Fan Shaft Diameter (in.)
Belt, Quantity...Type...Length (in.)
Pulley Center Line Distance (in.)
Speed Change per Full Turn of
Movable Pulley Flange (rpm)
Movable Pulley Maximum Full Turns
From Closed Position
Factory Setting
Factory Speed Setting (rpm)
Fan Shaft Diameter at Pulley (in.)
016D/E
208/230,460 v
15
575 v
1650/1650
1800/1800
1930/1930
110
200
020D
024D/E
028D/E
18
20
25
2150
2200/2400
2300
2350/2550
2430
2480/2680
110
110
200
200/213
Semi-Hermetic
2
2
88,115
115 ea
R-22
Acutrol™ Refrigerant Metering
1
115
TXV
2250/2450
2400/2600
2530/2730
110
200/213
2
128 ea
Device
19-4
13-4
12-13
16-12
—
11-0
12-13
15-12
Enhanced Copper Tubes, Aluminum Lanced or Copper Fins
2...17
3...15
3...15
4...15
22.2
22.2
22.2
22.2
Propeller Type
10,500
10,500
14,200
14,200
3...22
3...22
2...30
2...30
1⁄2...1050
1⁄2...1050
1...1075
1...1075
1100
1100
3400
3400
Copper Tubes, Aluminum or Copper Plate Fins
2...17
3...17
4...15
4...15
17.9
17.9
17.9
17.9
Centrifugal Type
2...10 x 10
2...10 x 10 2...12 x 12
2...12 x 12
2...12 x 12
Belt
Belt
Belt
Belt
Belt
6000
6000
7200
8000
10,000
3.7
3.0
5
71⁄2
10
8.7 [208/230,575 v] 10.2 [208/230,575 v]
4.25
3.45
5.90
9.5 [460 v]
11.8 [460 v]
56H
56H
184T
213T
215T
—
—
—
—
—
1227-1559
1201-1462 1047-1251
1238-1494
1323-1579
Ball
Ball
Ball
Ball
Ball
1559
1550
1550
1550
1550
3.7/4.7
4.3/5.3
4.9/5.9
5.4/6.4
5.8/7.0
7 ⁄8
7⁄8
1 1 ⁄8
1 3 ⁄8
13⁄8
5.2
6.4
8.4
7.9
7.9
13⁄16
13⁄16
17⁄16
17⁄16
17⁄16
1...BX...42
1...BX...45
1...BX...50
1...BX...50
1...BX...51
13.5-15.5
13.5-15.5
13.3-14.8
14.6-15.4
14.6-15.4
66
52
34
43
43
4
3.5
1294
13⁄16
5
3.5
1279
13⁄16
6
3
1149
7
1 ⁄16
6
3
1366
7
1 ⁄16
6
3
1451
7
1 ⁄16
LEGEND
††Rollout switch is manual reset.
\The 48TJ028 unit requires 2-in. industrial-grade filters capable of
handling face velocities of up to 625 ft/min (such as American Air
Filter no. 5700 or equivalent).
Al
— Aluminum
Bhp — Brake Horsepower
Cu — Copper
TXV — Thermostatic Expansion Valve
*Evaporator coil fin material/condenser coil fin material.
†Weight of 14-in. roof curb.
**Circuit 1 consists of lower portion of condenser coil and lower portion of evaporator coil, and Circuit 2 is the upper portion of both
coils.
NOTE: Units have a low-pressure switch (standard) located on the
suction side.
7
Table 1 — Physical Data (cont)
UNIT SIZE
FURNACE SECTION
Rollout Switch Cutout
Temp (F)††
Burner Orifice Diameter
(in. ...drill size)
Natural Gas
Pilot Orifice Diameter
(Quantity) in. ...drill size
Natural Gas
Thermostat Heat Anticipator
Setting (amps)
208/230,575 v Stage 1
Stage 2
460 v Stage 1
Stage 2
Gas Input (Btuh) Stage 1
Stage 2
Efficiency (Steady
State) (%)
Temperature Rise Range
Manifold Pressure
(in. wg)
Natural Gas
Gas Valve Quantity
Field Gas Connection
Size (in.)
HIGH-PRESSURE SWITCH (psig)
Standard Compressor
Internal Relief (Differential)
Cutout
Reset (Auto.)
LOW-PRESSURE SWITCH (psig)
Cutout
Reset (Auto.)
FREEZE PROTECTION
THERMOSTAT (F)
Opens
Closes
OUTDOOR-AIR INLET SCREENS
Quantity...Size (in.)
016D/E
020D
024D/E
028D/E
190
190
190
190
.113...33
.113...33
.113...33
.113...33
(1) .055...54/
(1) .055...54,
(1) .041...59
(1) .055...54
(1) .041...59
(1) .055...54,
(1) .041...59/
(2) .070...50
0.98
0.44
0.80
0.44
115,500/115,500
231,000/270,000
0.98
0.44
0.80
0.44
115,500
270,000
0.98
0.44
0.80
0.44
115,500/242,500
270,000/485,000
0.98
0.44
0.80
0.44
115,500/242,500
270,000/485,000
80
25-55/25-55
80
15-45
80
15-45/35-65
80
15-45/35-65
3.5
2
3.5
2
3.5
2
3.5
2
⁄
34
⁄
34
⁄
34
34
(1) .055...54,
(1) .041...59/
(2) .070...50
⁄
—
426
320
7
22
30 ± 5
45 ± 5
Cleanable
2...20 x 25 x 1
1...20 x 20 x 1
Throwaway \
4...20 x 20 x 2
4...16 x 20 x 2
RETURN-AIR FILTERS
Quantity...Size (in.)
LEGEND
††Rollout switch is manual reset.
\The 48TJ028 unit requires 2-in. industrial-grade filters capable of
handling face velocities of up to 625 ft/min (such as American Air
Filter no. 5700 or equivalent).
Al
— Aluminum
Bhp — Brake Horsepower
Cu — Copper
TXV — Thermostatic Expansion Valve
*Evaporator coil fin material/condenser coil fin material.
†Weight of 14-in. roof curb.
**Circuit 1 consists of lower portion of condenser coil and lower portion of evaporator coil, and Circuit 2 is the upper portion of both
coils.
NOTE: Units have a low-pressure switch (standard) located on the
suction side.
8
Ductwork openings are shown in Fig. 1 and 4-6. Duct connections are shown in Fig. 7. Field-fabricated concentric
ductwork may be connected as shown in Fig. 8 and 9. Attach
all ductwork to roof curb and roof curb basepans.
Step 3 — Field Fabricate Ductwork — Secure all
ducts to building structure. Use flexible duct connectors between unit and ducts as required. Insulate and weatherproof
all external ductwork, joints, and roof openings with counter
flashing and mastic in accordance with applicable codes.
Ducts passing through an unconditioned space must be
insulated and covered with a vapor barrier.
Step 5 — Install Flue Hood — Flue hood is shipped
Step 4 — Make Unit Duct Connections — Unit
is shipped for through-the-bottom duct connections.
secured under main control box. To install, secure flue hood
to access panel. See Fig. 10 and 11.
NOTE: When properly installed, flue hood will line up with
combustion fan housing. See Fig. 12 and 13.
NOTE: Do not drill in this area; damage to basepan may result in
water leak.
NOTE: Dimensions A, A8, B, and B8 are obtained from field-supplied
ceiling diffuser.
Shaded areas indicate block-off pans.
Fig. 7 — Air Distribution — Through-the-Bottom
(48TJ028-028 Shown)
Fig. 9 — Concentric Duct Details
NOTE: Do not drill in this area; damage to basepan may result in
water leak.
Fig. 8 — Concentric Duct Air Distribution
(48TJ020-028 Shown)
Fig. 10 — Flue Hood Location, 48TJD Low-Heat and
48TJE016 High-Heat Units
9
Fig. 11 — Flue Hood Locations, 48TJE024 and 028
High-Heat Units
Fig. 13 — Combustion Fan Housing Location,
48TJE024 and 028 High-Heat Units
Step 6 — Trap Condensate Drain — See Fig. 14
for drain location. One 3⁄4-in. half coupling is provided
inside unit evaporator section for condensate drain connection. An 81⁄2 in. x 3⁄4-in. diameter and 2-in. x 3⁄4-in. diameter
pipe nipple, coupled to standard 3⁄4-in. diameter elbows, provides a straight path down through hole in unit base rail (see
Fig. 15). A trap at least 4-in. deep must be used.
PRESSURE
SWITCH
Step 7 — Install Gas Piping — Unit is equipped for
use with natural gas. Installation must conform with local
building codes or, in the absence of local codes, with the
National Fuel Gas Code, ANSI Z223.1.
Install manual gas shutoff valve with a 1⁄8-in. NPT pressure tap for test gage connection at unit. Field gas piping
must include sediment trap and union. See Fig. 16.
COMBUSTION
FAN HOUSING
Do not pressure test gas supply while connected to unit.
Always disconnect union before servicing.
Natural gas pressure at unit gas connection must not be
less than 5 in. wg or greater than 13.5 in. wg.
Size gas-supply piping for 0.5-in. wg maximum pressure
drop. Do not use supply pipe smaller than unit gas
connection.
HEAT
EXCHANGER
SECTION
Step 8 — Make Electrical Connections
FIELD POWER SUPPLY — Unit is factory wired for voltage shown on unit nameplate.
When installing units, provide a disconnect per NEC
(National Electrical Code) of adequate size (Table 2).
Fig. 12 — Combustion Fan Housing Location,
48TJD Low-Heat Units and
48TJE016 High-Heat Units
10
All field wiring must comply with NEC and local
requirements.
Route power and ground lines through control box end
panel or unit basepan (see Fig. 4-6) to connections as shown
on unit wiring diagram and Fig. 17.
The unit must be electrically grounded in accordance
with local codes and NEC ANSI/NFPA 70 (National Fire
Protection Association).
3/4" FPT DRAIN
CONNECTION
Field wiring must conform to temperature limitations for
type ‘‘T’’ wire. All field wiring must comply with NEC and
local requirements.
Transformer no. 1 is wired for 230-v unit. If 208/230-v
unit is to be run with 208-v power supply, the transformer
must be rewired as follows:
1. Remove cap from red (208 v) wire.
2. Remove cap from orange (230 v) spliced wire.
3. Replace orange wire with red wire.
4. Recap both wires.
1-3/8"
DRAIN HOLE
Fig. 14 — Condensate Drain Details
(48TJ016 Shown)
IMPORTANT: BE CERTAIN UNUSED WIRES
ARE CAPPED. Failure to do so may damage the
transformers.
Operating voltage to compressor must be within voltage
range indicated on unit nameplate. On 3-phase units, voltages between phases must be balanced within 2%.
Unit failure as a result of operation on improper line voltage or excessive phase imbalance constitutes abuse and may
cause damage to electrical components.
FIELD CONTROL WIRING — Install a Carrier-approved
accessory thermostat assembly according to installation instructions included with accessory. Locate thermostat assembly on a solid interior wall in the conditioned space to
sense average temperature.
Fig. 15 — Condensate Drain Piping Details
NOTE: The maximum wire size for TB1 is 2/0.
LEGEND
EQUIP
GND
NEC
TB
Fig. 16 — Field Gas Piping
—
—
—
—
Equipment
Ground
National Electrical Code
Terminal Board
Fig. 17 — Field Power Wiring Connections
11
Table 2 — Electrical Data
COMPRESSOR
VOLTAGE
OFM
NOMINAL
RANGE
UNIT
NO.
1
NO. 2
48TJ (60 VOLTAGE
Hz, 3 Phase) Min Max RLA LRA RLA LRA Qty Hp FLA
(ea)
016
020
024
028
IFM
POWER COMBUSTIONEXHAUST FAN MOTOR* POWER SUPPLY
FLA
FLA LRA
FLA
MCA
MOCP†
—
4.6
—
2.3
—
2.1
—
4.6
—
2.3
—
2.1
—
4.6
—
2.3
—
2.1
—
4.6
—
2.3
—
2.1
0.57
0.57
0.30
0.30
0.57
0.57
0.57
0.57
0.30
0.30
0.57
0.57
0.57
0.57
0.30
0.30
0.57
0.57
0.57
0.57
0.30
0.30
0.57
0.57
92/92
96/96
42
45
35
37
94/94
98/98
47
49
37
40
116/116
121/121
59
61
49
51
137/137
142/142
70
72
60
62
150/150
150/150
70
70
50
60
125/125
125/125
60
60
50
50
150/150
150/150
70
70
60
60
175/175
175/175
90
90
70
80
⁄
1.70 10.5/10.5
12
⁄
0.80
4.8
⁄
0.75
3.9
⁄
1.70 15.8/15.8
12
⁄
0.80
7.9
⁄
0.75
6.0
2
1
5.50 25.0/25.0
99
2
1
2.80
13.0
14.3
79
2
1
3.40
10.0
228
43.6
228
2
1
5.50 28.0/28.0
22.1
114
22.1
114
2
1
2.80
14.6
17.9
91
17.9
91
2
1
3.40
13.0
208/230
187
254
61.0
266
—
—
3
12
460
414
508
28.0
120
—
—
3
575
518
632
23.0
96
—
—
3
12
208/230
187
254
35.6
198
28.2
160
3
12
460
414
508
17.8
99
14.1
80
3
575
518
632
14.3
79
11.3
64
3
12
208/230
187
254
35.6
198
35.6
198
460
414
508
17.8
99
17.8
575
518
632
14.3
79
208/230
187
254
43.6
460
414
508
575
518
632
LEGEND
—
18.8
—
6.0
—
4.8
—
18.8
—
6.0
—
4.8
—
18.8
—
6.0
—
4.8
—
18.8
—
6.0
—
4.8
% Voltage Imbalance
= 100 x max voltage deviation from average voltage
average voltage
FLA
— Full Load Amps
HACR — Heating, Air Conditioning and Refrigeration
IFM
— Indoor (Evaporator) Fan Motor
LRA
— Locked Rotor Amps
MCA — Minimum Circuit Amps
MOCP — Maximum Overcurrent Protection
NEC
— National Electrical Code
OFM
— Outdoor (Condenser) Fan Motor
RLA
— Rated Load Amps
*The 48TJ024 and 028 high-heat units have 2 combustion-fan
motors.
†Fuse or HACR circuit breaker.
EXAMPLE: Supply voltage is 460-3-60.
AB = 452 v
BC = 464 v
AC = 455 v
452 + 464 + 455
3
1371
=
3
= 457
Average Voltage =
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 voltage imbalance.
7
% Voltage Imbalance = 100 x
457
= 1.53%
NOTES:
1. In compliance with NEC requirements for multimotor and combination load equipment (refer to NEC Articles 430 and 440), the
overcurrent protective device for the unit shall be fuse or HACR
breaker. Canadian units may be fuse or circuit breaker.
2. Unbalanced 3-Phase Supply Voltage
Never operate a motor where a phase imbalance in supply voltage is greater than 2%. Use the following formula to determine
the percent voltage imbalance.
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
Route thermostat cable or equivalent single leads of colored wire from subbase terminals through conduit in unit to
low-voltage connections as shown on unit label wiring diagram and in Fig. 18.
NOTE: For wire runs up to 50 ft, use no. 18 AWG (American Wire Gage) insulated wire (35 C minimum). For 50 to
75 ft, use no. 16 AWG insulated wire (35 C minimum). For
over 75 ft, use no. 14 AWG insulated wire (35 C Minimum).
All wire larger than no. 18 AWG cannot be directly connected at the thermostat and will require a junction box and
splice at the thermostat.
Set heat anticipator settings as follows:
VOLTAGE
208/230,575
460
W1
0.98
0.80
W2
0.44
0.44
Settings may be changed slightly to provide a greater degree of comfort for a particular installation.
Refer to Accessory Remote Control Panel instructions if
required.
Step 9 — Make Outdoor-Air Inlet
Adjustments
Fig. 20 — Economizer Damper
Assembly-End View
MANUAL OUTDOOR-AIR DAMPER — All units (except
those equipped with a factory-installed economizer) have a
manual outdoor-air damper to provide ventilation air.
Damper can be preset to admit up to 25% outdoor air into
return-air compartment. To adjust, loosen securing screws
and move damper to desired setting, then retighten screws to
secure damper (Fig. 19).
OPTIONAL ECONOMIZER
Economizer Motor Control Module (See Fig. 20-22) — Set
economizer motor to the D setting (Fig. 21).
Damper Vent Position Setting
1. Set fan switch at ON position (continuous fan operation)
and close night switch if used.
2. Set system selector switch at OFF position.
3. Turn damper adjustment knob located on control module
clockwise slowly until dampers assume desired vent position. Do not manually operate economizer motor. Damage to motor will result.
LED — Light-Emitting Diode
Fig. 21 — Economizer Motor Control Module
Step 10 — Install Outdoor-Air Hood — The outdoorair hood is common to 25% air ventilation and economizer.
If economizer is used, all electrical connections have been
made and adjusted at the factory. Assemble and install hood
in the field.
NOTE: The hood top panel, upper and lower filter retainers, hood drain pan, baffle (020-028), and filter support bracket
are secured opposite the condenser end of the unit. The screens,
hood side panels, remaining section of filter support bracket,
seal strip, and hardware are in a package located inside the
return-air filter access panel (Fig. 23).
1. Attach seal strip to upper filter retainer. See Fig. 24.
2. Assemble hood top panel, side panels, upper filter
retainer, and drain pan (see Fig. 25).
3. Secure lower filter retainer and support bracket to unit.
See Fig. 25. Leave screws loose on 020-028 units.
4. Slide baffle (020-028) behind lower filter retainer and tighten
screws.
Fig. 18 — Field Control Thermostat Wiring
Fig. 19 — 25% Outdoor-Air Section Details
13
Fig. 25 — Outdoor-Air Hood Details
5. Loosen sheet metal screws for top panel of base unit
located above outdoor-air inlet opening, and remove screws
for hood side panels located on the sides of the outdoorair inlet opening.
6. Match notches in hood top panel with unit top panel screws.
Insert hood flange between top panel flange and unit. Tighten
screws.
7. Hold hood side panel flanges flat against unit, and install
screws removed in Step 5.
8. Insert outdoor-air inlet screens and spacer in channel
created by lower filter retainer and filter support bracket.
9. Attach remaining section of filter support bracket.
Fig. 22 — Economizer Motor Control
Module Location
START-UP
Use the following information and Start-Up Checklist
on page CL-1 to check out unit PRIOR to start-up.
Unit Preparation — Check that unit has been installed
in accordance with these installation instructions and applicable codes.
Compressor Mounting — Loosen the compressor holddown bolts until sidewise movement of the washer under
each holddown bolt head can be obtained. Do not loosen
completely as bolts are self-locking and will maintain
adjustment.
Fig. 23 — Outdoor-Air Hood Component Location
Internal Wiring — Check all electrical connections in
unit control boxes; tighten as required.
Refrigerant Service Ports — Each refrigerant system has 1 suction port located in the top of the compressor
motor casing. All units also have one service port on the liquid line and one on either the compressor discharge flange
or discharge line. Be sure that caps on the ports are tight.
Crankcase Heater(s) — Crankcase heater(s) is energized as long as there is power to the unit.
IMPORTANT: Unit power must be on for 24 hours
prior to start-up. Otherwise, damage to compressor may
result.
Evaporator Fan — Fan belt and variable pulleys are
factory-installed. See Tables 3-7 for Fan Performance Data.
Remove tape from fan pulley, and be sure that fans rotate in
the proper direction. See Table 8 for air quantity limits. See
Tables 9 and 10 for static pressure information for accessories and options. See Table 11 for fan rpm at various motor
pulley settings. To alter fan performance, see Evaporator Fan
Performance Adjustment section on page 20.
Fig. 24 — Seal Strip Location
14
Condenser-Fans and Motors — Condenser fans and
Gas Heat — Verify gas pressures before turning on heat
as follows:
1. Turn off manual gas stop.
2. Connect pressure gage to supply gas pressure tap (See
Fig. 16).
3. Connect pressure gage to manifold pressure tap on gas
valve.
4. Turn on manual gas stop and set thermostat to HEAT position. After the unit has run for several minutes, verify
that incoming pressure is 5.0 in. wg or greater, and that
the manifold pressure is 3.5 in. wg. If manifold pressure
must be adjusted, refer to Gas Valve Adjustment section
on page 24.
5. After unit has been in operation for 5 minutes, check temperature rise across the heat exchangers. See unit informative plate for correct rise limits of the heat supplied.
Air quantities may need to be adjusted to bring the actual
rise to within the allowable limits.
motors are factory set. Refer to Condenser-Fan Adjustment
section on page 21 as required. Be sure that fans rotate in the
proper direction.
Return-Air Filters — Check that correct filters are installed in filter tracks (see Table 1). Do not operate unit without return-air filters.
Outdoor-Air Inlet Screens — Outdoor-air inlet screens
must be in place before operating unit.
Accessory Economizer Adjustment — Remove
filter access panel. Check that outdoor-air damper is closed
and return-air damper is open.
Economizer operation and adjustment are described in
Base Unit Operation section on page 18, and in Economizer
Adjustment section on page 22.
Table 3 — Fan Performance Data, 48TJ016 — 208/230-V and 460-V Units
AIRFLOW
(Cfm)
4500
4800
5100
5400
5700
6000
6300
6600
6900
7200
7500
AIRFLOW
(Cfm)
4500
4800
5100
5400
5700
6000
6300
6600
6900
7200
7500
Rpm
801
843
885
927
971
1016
1059
1104
1150
1194
1238
EXTERNAL STATIC PRESSURE (in. wg)
0.2
0.4
0.6
0.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
1.05
933
890 1.26 1119
971 1.46 1297 1050 1.67 1483
1.25 1110
928 1.47 1306 1006 1.68 1492 1081 1.90 1687
1.47 1306
968 1.70 1510 1043 1.93 1714 1114 2.16 1918
1.71 1519 1008 1.95 1732 1080 2.20 1954 1148 2.44 2167
1.98 1758 1049 2.24 1989 1118 2.50 2220 1134 2.75 2442
2.28 2025 1091 2.55 2265 1158 2.83 2513 1222 3.10 2753
2.60 2309 1133 2.89 2567 1198 3.17 2815 1259 3.46 3073
2.96 2629 1174 3.26 2895 1239 3.56 3162 1297 3.86 3428
3.35 2975 1218 3.67 3259 1281 3.98 3535
—
—
—
3.77 3348 1260 4.10 3641
—
—
—
—
—
—
4.23 3758
—
—
—
—
—
—
—
—
—
Rpm
1275
1293
1316
1342
1370
1401
—
—
—
—
—
EXTERNAL STATIC PRESSURE (in. wg)
1.4
1.6
1.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
2.39 2123 1349 2.70 2398 1421 3.03 2691
2.62 2327 1364 2.92 2593 1433 3.24 2877
2.90 2575 1382 3.18 2824 1448 3.49 3099
3.20 2842 1403 3.47 3082 1466 3.77 3348
3.54 3144 1429 3.81 3384 1487 4.11 3650
3.92 3481 1458 4.20 3730
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
LEGEND
Bhp — Brake Horsepower Input to Fan
FIOP — Factory Installed Option
Watts — Input Watts to Motor
NOTES:
1. Factory shipped motor drive range is 1227 to 1559 rpm. Other rpms
require a field-supplied drive.
2. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Fan Performance table. See
Table 9 for accessory/FIOP static pressure information.
Rpm
1490
1501
1514
1529
—
—
—
—
—
—
—
Rpm
1125
1153
1183
1214
1247
1282
1318
1355
—
—
—
1.0
1.2
Bhp Watts Rpm Bhp Watts
1.88 1670 1200 2.12 1883
2.13 1892 1223 2.36 2096
2.40 2131 1250 2.64 2345
2.69 2389 1279 2.94 2611
3.01 2673 1309 3.28 2913
3.36 2984 1342 3.64 3233
3.74 3321 1375 4.02 3570
4.15 3686
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
2.0
Bhp Watts
3.39 3011
3.59 3188
3.86 3428
4.16 3694
—
—
—
—
—
—
—
—
—
—
—
—
—
—
3. Interpolation is permissible. Do not extrapolate.
4. Maximum continuous bhp is 4.25 and the maximum continuous
watts are 3775. Extensive motor and drive testing on these units
ensures that the full horsepower range of the motor can be utilized with confidence. Using your fan motors up to the watts rating
shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected.
15
Table 4 — Fan Performance Data, 48TJ016 — 575-V Units
AIRFLOW
(Cfm)
4500
4800
5100
5400
5700
6000
6300
6600
6900
7200
7500
AIRFLOW
(Cfm)
4500
4800
5100
5400
5700
6000
6300
6600
6900
7200
7500
Rpm
801
843
885
927
971
1016
1059
1104
1150
—
—
EXTERNAL STATIC PRESSURE (in. wg)
0.2
0.4
0.6
0.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
1.05
933
890 1.26 1119
971 1.46 1297 1050 1.67 1483
1.25 1110
928 1.47 1306 1006 1.68 1492 1081 1.90 1687
1.47 1306
968 1.70 1510 1043 1.93 1714 1114 2.16 1918
1.71 1519 1008 1.95 1732 1080 2.20 1954 1148 2.44 2167
1.98 1758 1049 2.24 1989 1118 2.50 2220 1134 2.75 2442
2.28 2025 1091 2.55 2265 1158 2.83 2513 1222 3.10 2753
2.60 2309 1133 2.89 2567 1198 3.17 2815
—
—
—
2.96 2629 1174 3.26 2895
—
—
—
—
—
—
3.35 2975
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Rpm
1275
1293
1316
1342
—
—
—
—
—
—
—
EXTERNAL STATIC PRESSURE (in. wg)
1.4
1.6
1.8
2.0
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
2.39 2123 1349 2.70 2398 1421 3.03 2691 1490 3.39 3011
2.62 2327 1364 2.92 2593 1433 3.24 2877
—
—
—
2.90 2575 1382 3.18 2824
—
—
—
—
—
—
3.20 2842
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
LEGEND
Bhp — Brake Horsepower Input to Fan
FIOP — Factory-Installed Option
Watts — Input Watts to Motor
NOTES:
1. Factory shipped motor drive range is 1201 to 1462 rpm. Other rpms
require a field-supplied drive.
2. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Fan Performance table. See
Table 9 for accessory/FIOP static pressure information.
Rpm
1125
1153
1183
1214
1247
1282
—
—
—
—
—
1.0
1.2
Bhp Watts Rpm Bhp Watts
1.88 1670 1200 2.12 1883
2.13 1892 1223 2.36 2096
2.40 2131 1250 2.64 2345
2.69 2389 1279 2.94 2611
3.01 2673 1309 3.28 2913
3.36 2984
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
3. Interpolation is permissible. Do not extrapolate.
4. Maximum continuous bhp is 3.45 and the maximum continuous
watts are 3065. Extensive motor and drive testing on these units
ensures that the full horsepower range of the motor can be utilized with confidence. Using your fan motors up to the watts rating
shown will not result in nuisance tripping or premature motor failure. Unit warranty will not be affected.
Table 5 — Fan Performance Data, 48TJ020
AIRFLOW
(CFM)
5000
5500
6000
6500
7000
7200
7500
8000
8500
9000
AIRFLOW
(Cfm)
5000
5500
6000
6500
7000
7200
7500
8000
8500
9000
Rpm
669
717
767
817
869
889
920
973
1026
1079
EXTERNAL STATIC PRESSURE (in. wg)
0.2
0.4
0.6
0.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
1.10 1019
772 1.40 1291
870 1.80 1582
963 2.10 1903
1.40 1292
813 1.80 1585
905 2.10 1892
992 2.50 2223
1.80 1617
858 2.20 1932
944 2.50 2256 1026 2.90 2600
2.20 1992
903 2.60 2329
985 3.00 2673 1062 3.40 3031
2.70 2427
950 3.10 2787 1028 3.50 3151 1102 3.90 3527
2.94 2624
969 3.34 2993 1046 3.74 3366 1118 4.18 3749
3.30 2919
998 3.70 3303 1073 4.10 3689 1143 4.60 4083
3.90 3476 1047 4.30 3886 1119 4.80 4294 1186 5.30 4708
4.60 4102 1097 5.10 4635 1166 5.60 4967
—
—
—
5.40 4800
—
—
—
—
—
—
—
—
—
Rpm
1178
1196
1218
1244
1275
1288
1307
—
—
—
EXTERNAL STATIC PRESSURE (in. wg)
1.3
1.4
1.6
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
3.15 2820 1218 3.40 3016 1295 3.80 3425
3.55 3164 1234 3.80 3366 1309 4.20 3789
4.00 3565 1251 4.20 3772 1327 4.70 4206
4.50 4022 1279 4.70 4233 1348 5.20 4677
5.05 4547 1308 5.30 4762
—
—
—
5.33 4783
—
—
—
—
—
—
5.75 5135
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
LEGEND
Rpm
1369
1381
1396
1415
—
—
—
—
—
—
Rpm
1052
1076
1104
1136
1172
1187
1210
1250
—
—
1.0
1.2
Bhp Watts Rpm Bhp Watts
2.50 2251 1137 2.90 2623
2.90 2680 1157 3.30 2962
3.30 2967 1181 3.80 3358
3.80 3410 1209 4.30 3811
4.40 3919 1241 4.80 4331
4.64 4147 1255 5.08 4564
5.00 4490 1275 5.50 4914
5.70 5131
—
—
—
—
—
—
—
—
—
—
—
—
—
1.8
Bhp Watts
4.30 3849
4.70 4229
5.20 4658
5.80 5139
—
—
—
—
—
—
—
—
—
—
—
—
3. Interpolation is permissible. Do not extrapolate.
4. Maximum continuous bhp is 5.9 and the maximum continuous watts
are 5180. Extensive motor and drive testing on these units ensures that the full horsepower range of the motor can be utilized
with confidence. Using your fan motors up to the watts rating shown
will not result in nuisance tripping or premature motor failure. Unit
warranty will not be affected.
Bhp — Brake Horsepower Input to Fan
FIOP — Factory-Installed Option
Watts — Input Watts to Motor
NOTES:
1. Factory shipped motor drive range is 1047 to 1251 rpm. Other rpms
require a field-supplied drive.
2. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Fan Performance table. See
Table 10 for accessory/FIOP static pressure information.
16
Table 6 — Fan Performance Data, 48TJ024
AIRFLOW
(CFM)
6000
6500
7000
7500
8000
8500
9000
9500
10,000
AIRFLOW
(Cfm)
6000
6500
7000
7500
8000
8500
9000
9500
10,000
Rpm
767
817
869
920
973
1026
1079
1133
1188
EXTERNAL STATIC PRESSURE (in. wg)
0.2
0.4
0.6
0.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
1.80 1617
858 2.20 1932
944 2.50 2256 1026 2.90 2600
2.20 1992
903 2.60 2329
985 3.00 2673 1062 3.40 3031
2.70 2427
950 3.10 2787 1028 3.50 3151 1102 3.90 3527
3.30 2919
998 3.70 3303 1073 4.10 3689 1143 4.60 4083
3.90 3476 1047 4.30 3886 1119 4.80 4294 1186 5.30 4708
4.60 4102 1097 5.10 4635 1166 5.60 4967 1231 6.00 5401
5.40 4800 1147 5.90 5257 1214 6.40 5714 1276 6.90 6171
6.20 5576 1199 6.80 6058 1263 7.30 6540 1323 7.90 7018
7.20 6432 1250 7.80 6939 1313 8.30 7444 1371 8.90 7946
Rpm
1255
1279
1308
1339
1373
1410
1449
1488
—
EXTERNAL STATIC PRESSURE (in. wg)
1.4
1.6
1.8
1.9
2.0
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
4.20 3772 1327 4.70 4206 1396 5.20 4658 1431 5.45 4884 1465 5.70 5110
4.70 4233 1348 5.20 4677 1415 5.80 5139 1449 6.10 5370 1482 6.40 5601
5.30 4762 1373 5.80 5215 1437 6.40 5686 1469 6.70 5922 1501 7.00 6157
6.00 5356 1401 6.50 5818 1462 7.00 6298 1493 7.25 6538 1523 7.50 6778
6.70 6024 1433 7.30 6495 1493 7.80 6966 1523 8.05 7202
—
—
—
7.60 6765 1467 8.10 7248 1524 8.70 7731
—
—
—
—
—
—
8.50 7584 1503 9.00 8033
—
—
—
—
—
—
—
—
—
9.40 8403
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Rpm
1104
1136
1172
1210
1250
1292
1336
1381
1426
1.0
1.2
Bhp Watts Rpm Bhp Watts
3.30 2967 1181 3.80 3358
3.80 3410 1209 4.30 3811
4.40 3919 1241 4.80 4331
5.00 4490 1275 5.50 4914
5.70 5131 1313 6.20 5569
6.50 5843 1352 7.00 6297
7.40 6632 1393 7.90 7102
8.40 7500 1436 8.90 7988
9.50 8449
—
—
—
4. Interpolation is permissible. Do not extrapolate.
5. Maximum continuous bhp is 8.7 for 208/230 and 575-v units and
9.5 for 460-v units. The maximum continuous watts are 7915 for
the 208/230 and 575-v units and 8640 for the 460-v units. Extensive motor and drive testing on these units ensures that the full
horsepower range of the motor can be utilized with confidence.
Using your fan motors up to the watts rating shown will not result
in nuisance tripping or premature motor failure. Unit warranty will
not be affected.
LEGEND
Bhp — Brake Horsepower Input to Fan
FIOP — Factory-Installed Option
Watts — Input Watts to Motor
NOTES:
1. Boldface indicates additional capability of the 460-v motor.
2. Factory shipped motor drive range is 1238 to 1494 rpm. Other rpms
require a field-supplied drive.
3. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Fan Performance table. See
Table 10 for accessory/FIOP static pressure information.
Table 7 — Fan Performance Data, 48TJ028
AIRFLOW
(CFM)
7,500
8,000
8,500
9,000
9,500
10,000
10,500
11,000
11,250
AIRFLOW
(Cfm)
7,500
8,000
8,500
9,000
9,500
10,000
10,500
11,000
11,250
Rpm
962
1017
1072
1128
1185
1241
1298
1355
1384
Rpm
1309
1349
1390
1433
1478
1524
—
—
—
0.2
Bhp
3.39
4.04
4.76
5.57
6.47
7.45
8.54
9.72
10.36
Watts
3123
3717
4385
5129
5955
6865
7865
8956
9540
Rpm
1039
1091
1143
1196
1250
1304
1359
1414
1441
EXTERNAL STATIC PRESSURE (in. wg)
0.4
0.6
0.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
3.81 3507 1111 4.23 3895 1179 4.66 4295
4.48 4126 1160 4.93 4536 1225 5.38 4954
5.23 4818 1209 5.70 5250 1271 6.18 5688
6.07 5587 1260 6.56 6042 1320 7.06 6501
6.99 6437 1311 7.51 6915 1369 8.03 7395
8.00 7372 1363 8.55 7873 1419 9.09 8376
9.12 8396 1415 9.69 8921 1469 10.26 9446
10.33 9512 1469 10.93 10,062 1521 11.52 10,609
10.97 10,107 1495 11.58 10,668 —
—
—
0.9
Rpm Bhp
1212 4.89
1256 5.62
1302 6.42
1348 7.32
1396 8.30
1445 9.37
1495 10.55
—
—
—
—
Watts
4503
5170
5913
6735
7638
8629
9710
—
—
1.0
Rpm Bhp
1245 5.11
1287 5.85
1332 6.66
1377 7.57
1424 8.56
1472 9.64
1521 10.83
—
—
—
—
Watts
4710
5386
6137
6968
7881
8882
9973
—
—
EXTERNAL STATIC PRESSURE (in. wg)
1.2
1.3
1.4
1.6
1.8
Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts
5.58 5143 1341 5.83 5370 1372 6.08 5597 1434 6.59 6067 1494 7.12 6558
6.33 5833 1379 6.59 6065 1409 6.84 6297 1467 7.36 6779
—
—
—
7.17 6600 1419 7.43 6839 1447 7.68 7077 1504 8.22 7571
—
—
—
8.08 7446 1461 8.35 7692 1488 8.62 7938
—
—
—
—
—
—
9.10 8378 1505 9.37 8626
—
—
—
—
—
—
—
—
—
10.20 9396 1550 10.48 9653
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
LEGEND
Bhp — Brake Horsepower Input to Fan
FIOP — Factory-Installed Option
Watts — Input Watts to Motor
NOTES:
1. Boldface indicates additional capability of the 460-v motor.
2. Factory shipped motor drive range is 1323 to 1579 rpm. Other rpms
require a field-supplied drive.
3. Static pressure losses (i.e., economizer) must be added to external static pressure before entering Fan Performance table. See
Table 10 for accessory/FIOP static pressure information.
4. Interpolation is permissible. Do not extrapolate.
5. Fan performance is based on wet coils, clean filters, and casing
losses.
6. Maximum continuous bhp is 10.2 for 208/230 and 575-v units and
11.8 for 460-v units. The maximum continuous watts are 9510 for
the 208/230 and 575-v units and 11,000 for the 460-v units. Extensive motor and drive testing on these units ensures that the full
horsepower range of the motor can be utilized with confidence.
Using your fan motors up to the watts rating shown will not result
in nuisance tripping or premature motor failure. Unit warranty will
not be affected.
17
Table 8 — Air Quantity Limits
UNIT 48TJ
016
020
024
028
MINIMUM CFM
4500
5400
6000
7500
MAXIMUM CFM
7,500
9,000
10,000
11,250
Table 9 — Accessory/FIOP Static Pressure* (in. wg) — 48TJ016
COMPONENT
4500
0.04
Economizer
CFM
6000
0.07
5000
0.05
7200
0.09
7500
0.10
LEGEND
FIOP — Factory-Installed Option
*The static pressure must be added to external static pressure. The sum and the evaporator enteringair cfm should then be used in conjunction with the Fan Performance tables to determine blower rpm
and watts.
Table 10 — Accessory/FIOP Static Pressure* (in. wg) — 48TJ020-028
COMPONENT
Economizer
5000
0.06
6000
0.07
7200
0.09
CFM
9000
0.11
10,000
0.12
11,250
0.14
LEGEND
FIOP — Factory-Installed Option
*The static pressure must be added to external static pressure. The sum and the evaporator enteringair cfm should then be used in conjunction with the Fan Performance tables to determine blower rpm
and watts.
Table 11 — Fan Rpm at Motor Pulley Settings*
UNIT
48TJ
016 (208/230,460 v)
016 (575 v)
020
024
028
0
1559
1462
1251
1494
†
⁄
1524
1436
1234
1472
†
12
1
1491
1410
1217
1451
1536
11⁄2
1458
1384
1200
1430
1515
MOTOR PULLEY TURNS OPEN
2
21⁄2
3
31⁄2
4
1425
1392
1359
1326
1293
1358
1332
1305
1279
1253
1183
1166
1149
1132
1115
1408
1387
1366
1345
1323
1493
1472
1451
1430
1408
41⁄2
1260
1227
1098
1302
1387
5
1227
1201
1081
1281
1366
51⁄2
—
—
1064
1259
1344
6
—
—
1047
1238
1323
*Approximate fan rpm shown.
†Do not run this fan at less than 1 full turn open, as it will exceed the maximum allowable rpm of 1550.
When sequence is complete, time-delay relay closes and
evaporator fans start.
Second-Stage — 48TJD016-028 Low-Heat and 48TJE016
High Heat Units — With an additional heating call, the secondstage thermostat closes. (The control relay [HR2] closes during the first stage of operation.) Pilot valve no. 2 opens, and
the spark ignitor ignites pilot. The sensor detects a flame and
energizes main gas valve coil no. 2, opening main gas valve
no. 2. Gas flows to the main burners, and the second-stage
burners ignite. The spark ignitor turns off.
When the second-stage thermostat is satisfied, the secondstage gas valve closes.
When the first-stage thermostat is satisfied, the first-stage
gas valve closes. The induced-draft motor turns off, the time
delay relay opens, and the timer sequence begins. When the
sequence is complete, the evaporator-fan motor turns off.
Second-Stage — 48TJE024,028 High-Heat Units — With
an additional heating call, the second-stage thermostat closes.
(The control relay [HR2] closes during the first stage of operation.) The second-stage induced-draft relay closes, and the
second-stage induced-draft motor starts.
The second-stage pressure switch closes and pilot valve
no. 2 opens, allowing gas to flow to the second-stage pilot.
Spark ignitor ignites pilot flame. The sensor detects the flame,
and main gas valve no. 2 opens. Gas flows to main burners
and second-stage burners ignite. Spark ignitor turns off.
Base Unit Operation
COOLING, UNITS WITHOUT ECONOMIZER — When
thermostat calls for cooling, terminals G and Y1 are energized. The indoor (evaporator) fan contactor (IFC) and
compressor contactor no. 1 (C1) are energized and evaporatorfan motor (IFM), compressor no. 1 (48TJ020-028) or unloaded compressor (48TJ016), and condenser fan start. The
condenser-fan motors run continuously while unit is cooling. If the thermostat calls for a second stage of cooling by
energizing Y2, compressor contactor no. 2 (C2) is energized
and compressor no. 2 starts (48TJ020-028), or compressor
no. 1 runs fully loaded (48TJ016).
HEATING, UNITS WITHOUT ECONOMIZER
NOTE: The 48TJ016-028 units have 2 stages of heat.
First Stage — All Units — Turn unit power on. Open manual
gas line valve. Set thermostat system switch at HEAT or AUTO.
position and set fan switch to AUTO. position for heating.
First-stage thermostat calls for heat. Time-delay relay for
evaporator fan begins timer sequence. Induced-draft relay
closes, and induced-draft motor starts.
Pressure switch closes and pilot valve no. 1 opens, allowing gas to flow to the first-stage pilot. Spark ignitor ignites
pilot flame. Sensor detects flame and the main gas valve no.
1 opens. Gas flows to main burners and first-stage burners
ignite. Spark ignitor turns off.
18
removing screws holding motor mounting plate to top of combustion fan housing (Fig. 26 and 27). The motor and wheel
assembly will slide up and out of the fan housing. Remove
the blower wheel from the motor shaft and clean with a detergent or solvent. Replace motor and wheel assembly.
EVAPORATOR COIL — Clean as required with commercial coil cleaner.
CONDENSER COIL — Clean condenser coil annually and
as required by location and outdoor-air conditions. Inspect
coil monthly; clean as required.
CONDENSATE DRAIN — Check and clean each year at
start of cooling season. In winter, keep drains and traps dry.
FILTERS — Clean or replace at start of each heating and
cooling season, or more often if operating conditions require. Refer to Table 1 for type and size.
NOTE: The 48TJ028 unit requires industrial grade throwaway filters capable of withstanding face velocities up to
625 fpm. Ensure that replacement filters for the 48TJ028 units
are rated for 625 fpm.
When the second-stage thermostat is satisfied, the secondstage gas valve closes and the second-stage induced-draft
motor turns off.
When the first-stage thermostat is satisfied, the first-stage gas
valve closes. The first-stage induced-draft motor turns off,
the time relay opens, and the timer sequence begins. When
the sequence is complete, the evaporator-fan motor turns off.
COOLING, UNITS WITH ECONOMIZER — Upon a call
for cooling, when outdoor ambient is above the changeover
control setting, the economizer damper moves to VENT
position. The compressors and evaporator and condenser fans
energize and operate as per Cooling, Units Without Economizer section above.
Upon a first call for cooling, when outdoor ambient is below the changeover control setting, the evaporator fan starts
and the economizer is fully open. The compressors remain
off.
Upon a second-stage call for cooling, compressor no. 1
(48TJ020-028) or unloaded compressor (48TJ016) is energized and mechanical cooling is integrated with economizer cooling. If the outdoor-air temperature drops below
50 F, a cooling lockout switch prevents the compressors from
running.
When supply-air temperature drops below a fixed set point,
the economizer damper modulates to maintain the temperature at the fixed set point.
A freeze protection thermostat (FPT) is located on the evaporator coil. It detects frost build-up and locks out the compressors, allowing the coil to clear. Once frost has melted,
the compressors can be reenergized by resetting the
thermostat.
HEATING, UNITS WITH ECONOMIZER — Outdoor-air
damper stays at VENT position while evaporator fan is
operating.
SERVICE
Fig. 26 — Typical Gas Heating Section,
2-Stage Units
(48TJD Units Shown)
Before performing service or maintenance operations on
unit, turn off main power switch to unit. Electrical shock
could cause personal injury.
Cleaning — Inspect unit interior at beginning of each heating and cooling season and as operating conditions require.
Remove unit top panel and/or side panels for access to unit
interior.
MAIN AND PILOT BURNERS — At the beginning of each
heating season, inspect for deterioration or blockage due to
corrosion or other causes. Observe the pilot and main burner
flames through view port (in condenser section), and adjust
if necessary. Refer to Pilot Adjustment or Main Burners sections on page 24.
FLUE GAS PASSAGEWAYS — The flue collector box and
heat exchanger cells may be inspected by removing heat exchanger access panel (Fig. 4-6), flue box cover, and main
burner assembly (Fig. 26). Refer to Main Burners section on
page 24 for burner removal sequence. If cleaning is required, remove heat exchanger turbulators (Fig. 27) and clean
all parts with a wire brush.
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 bi-monthly to
determine proper cleaning frequency.
To inspect blower wheel, remove heat exchanger access
panel. Shine a flashlight into opening to inspect wheel. If
cleaning is required, remove motor and wheel assembly by
Fig. 27 — Typical Heating Section with Main
Burners Removed
(48TJD Units Shown)
19
4. Screw movable flange toward fixed flange to increase speed
and away from fixed flange to decrease speed. Increasing
fan speed increases load on motor. Do not exceed maximum speed specified in Table 1.
See Table 8 for air quantity limits.
5. Set movable flange at nearest keyway of pulley hub and
tighten setscrew. (See Table 1 for speed change for each
full turn of pulley flange.)
6. Replace and tighten belts (see Belt Tension Adjustment
section on page 21).
OUTDOOR-AIR INLET SCREENS — Clean screens with
steam or hot water and a mild detergent. Do not use throwaway filters in place of screens.
Lubrication
COMPRESSORS — Each compressor is charged with the
correct amount of oil at the factory. The 48TJ016 compressor runs with a slightly low sight glass oil level. Oil level
with compressor off should be about 1⁄4 of sight glass as shown
in Fig. 28.
If oil charge is above 1⁄4 sight glass, do not remove any oil
until the compressor crankcase heater has been energized for
at least 24 hours.
FAN SHAFT BEARINGS — For 016 units, bearings are permanently lubricated. No field lubrication is required. For 020028 units, lubricate bearings at least every 6 months with
suitable bearing grease. Extended grease line is provided for
far side fan bearing (opposite drive side). Typical lubricants
are given below:
MANUFACTURER
Texaco
Mobil
Sunoco
Texaco
To align fan and motor pulleys:
1. Loosen fan pulley setscrews.
2. Slide fan pulley along fan shaft.
3. Make angular alignment by loosening motor from mounting plate.
LUBRICANT
Regal AFB-2*
Mobilplex EP No. 1
Prestige 42
Multifak 2
*Preferred lubricant because it contains rust and oxidation inhibitors.
CONDENSER AND EVAPORATOR-FAN MOTOR
BEARINGS — The condenser- and evaporator-fan motors
have permanently-sealed bearings, so no field lubrication is
necessary.
Evaporator Fan Performance Adjustment
(Fig. 29-31) — Fan motor pulleys are factory set for speed
shown in Table 1.
To change fan speeds:
1. Shut off unit power supply.
2. a. 016 only: Loosen belt by loosening carriage nuts holding motor mount assembly to fan scroll side plates (A
and B).
b. 020-028 only: Loosen nuts on the 2 carriage bolts in
the mounting base. Install jacking bolt and plate under
motor base (bolt and plate are shipped in installer’s
packet). Using bolt and plate, raise motor to top of
slide and remove belt. Secure motor in this position
by tightening the nuts on the carriage bolts.
3. Loosen movable-pulley flange setscrew (see Fig. 29).
Fig. 29 — Evaporator-Fan Alignment and
Adjustment
Evaporator Fan Service and Replacement
48TJ016 UNITS (See Fig. 30)
NOTE: To remove belts only, follow Steps 1-6.
1. Remove filter and supply-air section panels.
2. Remove unit top panel.
3. Loosen carriage nuts A and B holding motor mount assembly to fan scroll side plates.
4. Loosen screw C.
5. Rotate motor mount assembly (with motor attached) as
far as possible away from evaporator coil.
6. Remove belt.
7. Rotate motor mount assembly back past original position toward evaporator coil.
8. Remove motor mounting nuts D and E (both sides).
9. Lift motor up through top of unit.
10. Reverse above procedure to reinstall motor.
11. Check and adjust belt tension as necessary.
Fig. 28 — 48TJ016 Compressor Sight Glass Oil Level
20
NOTE: A 31⁄2-in. bolt and threaded plate are included in the installer’s
packet. They can be added to the motor support channel below the
motor mounting plate to aid in raising the motor.
Fig. 31 — 48TJ020-028 Evaporator-Fan Motor
Section
Belt Tension Adjustment — To adjust belt tension:
Fig. 30 — 48TJ016 Evaporator-Fan
Motor Adjustment
1. Loosen fan motor bolts.
2. a. 016 Units:
Move motor mounting plate up or down for proper belt
tension (1⁄2 in. deflection with one finger).
48TJ020-028 UNITS (See Fig. 31) — The 48TJ020-028 units
use a fan motor mounting system that features a slide-out
motor mounting plate. To replace or service the motor, slide
out the bracket.
1. Remove the evaporator-fan access panel and the heating control access panel.
b. 020-028 Units:
Turn motor jacking bolt to move motor mounting plate
up or down for proper belt tension (3⁄8 in. deflection at
midspan with one finger [9 lb force]).
3. Tighten nuts.
4. Adjust bolts and nut on mounting plate to secure motor
in fixed position.
Condenser-Fan Adjustment
2. Remove the center post (located between the evaporator
fan and heating control access panels) and all screws
securing it.
3. Loosen nuts on the 2 carriage bolts in the motor mounting base.
4. Using jacking bolt under motor base, raise motor to top
of slide and remove belt. Secure motor in this position
by tightening the nuts on the carriage bolts.
5. Remove the belt drive.
6. Remove jacking bolt and tapped jacking bolt plate.
7. Remove the 2 screws that secure the motor mounting
plate to the motor support channel.
8. Remove the 3 screws from the end of the motor support
channel that interfere with the motor slide path.
9. Slide out the motor and motor mounting plate.
10. Disconnect wiring connections and remove the 4 mounting bolts.
11. Remove the motor.
12. To install the new motor, reverse Steps 1-11.
48TJ016,020 UNITS (Fig. 32)
1. Shut off unit power supply.
2. Remove access panel(s) closest to the fan to be adjusted.
3. Loosen fan hub setscrews.
4. Adjust fan height on shaft using a straightedge placed across
the fan orifice.
5. Tighten setscrews and replace panel(s).
6. Turn on unit power.
48TJ024,028 UNITS (Fig. 33)
1. Shut off unit power supply.
2. Remove fan top-grille assembly and loosen fan hub screws.
3. Adjust fan height on unit, using a straightedge placed across
the fan orifice.
4. Tighten setscrews and replace rubber hubcap to prevent
hub from rusting to motor shaft.
5. Fill hub recess with permagum if rubber hubcap is
missing.
21
Power Failure — Dampers have a spring return. In event
of power failure, dampers will return to fully closed position
until power is restored. Do not manually operate damper
motor.
Table 12 — Economizer Checkout Procedures
TEST PROCEDURE
A. Disconnect power at
TR and TR1.
Disconnect jumper
between P and
P1. See Fig. 21.
B. Jumper TR to 1.
C. Jumper T1 to T.
D. Disconnect outdoor-air
thermostat connections
from SO and +.
Factory-installed
800 ohm resistor
should remain connected
to SR and +.
E. Reconnect power to
terminals TR and TR1.
Fig. 32 — Condenser Fan Adjustment, 48TJ016,020
RESULTS
1. LED (light-emitting diode)
should be off.
2. Motor is in closed position.
Fig. 33 — Condenser-Fan Adjustment, 48TJ024,028
TEST PROCEDURE
Disconnect factory-installed
resistor from terminals
SR and +.
Economizer Adjustment — See Tables 12 and 13 for
checkout and enthalpy simulation. Make certain the
outdoor-air damper is fully closed and the return-air damper
is fully open before completing the following steps:
1. Turn on power to the unit.
2. Turn the thermostat fan switch to the ON position. The
damper will go to the vent position.
3. Adjust the vent position with the minimum damper position adjustment on the economizer motor control module. See Fig. 21.
4. Set the system selector switch to COOL position and set
the cooling temperature selector to its lowest setting.
NOTE: The cooling mode may also be simulated by removing the thermostat wires from terminals Y1 and Y2
and installing a jumper between terminals R and Y1. Refer to unit label diagram for terminal locations.
5. Set the outdoor-air thermostat (OAT), located in the economizer section of the unit (see Fig. 20) to 75 F.
6. If the outdoor temperature is below 75 F, the economizer will control the mixed air with the mixed-air sensor. If the outdoor air is above 75 F, place a jumper around
the contacts of the OAT.
7. Jumper terminal T to terminal T1 on the module (see
Fig. 21). The economizer will go to the full open position. The outdoor-air damper will go to the full open
position, and the return-air damper will go to the full
closed position.
8. Adjust mechanical linkage, if necessary, for correct positioning. If may be necessary to remove the filters to
adjust the linkage.
9. Remove the jumper from around the contacts of the OAT
if installed in Step 6. Remove the jumper from terminals T and T1 installed in Step 7.
10. If the cooling mode was simulated to operate the unit in
Step 4, remove the jumper and reconnect the thermostat
wires to terminals Y1 and Y2.
RESULTS
1 LED (light-emitting diode)
should be on.
2. Motor drives toward open.
Table 13 — High and Low Outdoor-Air Simulation
TEST PROCEDURE
A. Reconnect factory-installed
800 ohm resistor
between terminals
SR and +.
B. Connect 1200 ohm
checkout resistor between
terminals SO and +.
C. Turn set point potentiometer
to position A.
RESULTS
Low outdoor-air test results:
1. LED (light-emitting diode)
should be on.
2. Motor drives toward open.
D. Turn set point potentiometer
to position D.
E. Disconnect 1200 ohm
checkout resistor.
High outdoor-air test results:
1. LED should be off.
2. Motor drives toward closed.
Refrigerant Charge — Amount of refrigerant charge
is listed on unit nameplate and in Table 1. Refer to Carrier
GTAC II; Module 5; Charging, Recovery, Recycling, and
Reclamation section for charging methods and procedures.
Unit panels must be in place when unit is operating during charging procedure.
NO CHARGE — Use standard evacuating techniques. After
evacuating system, weigh in the specified amount of
refrigerant (refer to Table 1).
22
3. Check that ICP is securely grounded.
4. Check that high-voltage lead is securely connected between ICP and electrode body.
5. Restore power to ICP. Check that 24 v is supplied
LOW CHARGE COOLING — Using appropriate cooling
charging chart (see Fig. 34-37), add refrigerant until conditions of the appropriate chart are met. Note that 48TJ020028 charging charts are different from those normally used.
All charts are based on charging units to correct superheat
for various operating conditions. An accurate pressure gage
and temperature sensing device are required for all units.
Connect temperature sensing device to service port on suction line and insulate it so that outdoor ambient temperature
does not affect reading. Indoor-air cfm must be within normal operating range of unit.
TO USE COOLING CHARGING CHART, 48TJ016 UNITS
— The TXV is set to maintain between 10 and 13° F superheat leaving the evaporator coil. It controls the flow of refrigerant to the evaporator coil. Take the outdoor ambient
temperature, and read the suction pressure gage. Refer to
Fig. 34 to determine correct discharge pressure. If discharge
pressure is low, add refrigerant. If discharge pressure is high,
carefully recover some of the charge. Recheck discharge pressure as charge is adjusted.
TO USE COOLING CHARGING CHART, 48TJ020-028
UNITS — Take outdoor ambient temperature and read the
suction pressure gage. Refer to appropriate chart to determine correct suction temperature. If suction temperature is
high, add refrigerant. If suction temperature is low, carefully
recover some of the charge. Recheck suction pressure as charge
is adjusted.
Example (Fig. 36)
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 85 F
Suction Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 psig
Suction Temperature (should be) . . . . . . . . . . . . . . . . . 60 F
(Suction temperature may vary ± 5 F)
to terminal TH of ICP.
6. Check unit label diagram for correct terminal usage if any
wires are removed.
Fig. 34 — Cooling Charging Chart — 48TJ016
Fig. 35 — Cooling Charging Chart — 48TJ020
Pilot Light — If pilots do not light as described in StartUp, Gas Heat section on page 15, be sure that pilot orifice
is not obstructed, then check for spark ignitor malfunctions
as follows:
1. Shut off control supply power to ignitor control pack (ICP).
2. Check that spark gap is 1⁄8 in. 6 1⁄32 inch.
23
Pilot Adjustment
1. Set system selector switch at OFF position to shut off unit.
Turn off power to unit.
2. Remove screw cap cover on pilot gas valve to expose
pilot adjustment screw (See Fig. 38).
3. Turn valve knobs to pilot position.
4. Turn on power to unit. Set system selector switch to HEAT
position and set thermostat to a setting that will call for
heat. Pilot ignites.
5. With a small screwdriver, turn pilot adjustment screw until flame fully engulfs sensor. Flame can be observed through
view port (Fig. 39).
6. Replace cap on pilot gas valve. Turn off power to unit.
Return valve(s) to original position.
7. Check for proper burner operation by cycling the burners. Wait 30 seconds between burner cycles.
8. Check that all unit panels are in place before leaving unit.
Gas Valve Adjustment
NATURAL GAS — The gas valve opens and closes in response to the thermostat or limit control.
When power is supplied to valve terminals 3 and 4, the
pilot valve opens to the preset position. When power is supplied to terminals 1 and 2, the main valve opens to its preset
position.
The regular factory setting is stamped on the valve body
(3.5 in. wg).
To adjust regulator:
1. Set thermostat at setting for no call for heat.
2. Turn main gas valve to OFF position.
3. Remove 1⁄8-in. pipe plug from manifold or gas valve pressure tap connection. Install a suitable pressure-measuring
device.
4. Set main gas valve to ON position.
5. Set thermostat at setting to call for heat.
6. Remove screw cap covering regulator adjustment screw
(See Fig. 38).
7. Turn adjustment screw clockwise to increase pressure or
counterclockwise to decrease pressure.
8. Once desired pressure is established, set thermostat setting for no call for heat, turn off main gas valve, remove
pressure-measuring device, and replace 1⁄8-in. pipe plug
and screw cap.
Fig. 36 — Cooling Charging Chart — 48TJ024
Main Burners — For most applications, main burners
are factory set and should require no adjustment. However,
if burner adjustment is necessary:
1. Perform pilot adjustment.
2. Turn gas valve to ON position. Allow unit to operate at
least 15 minutes with burner access panel in place.
3. Remove access panel.
4. Loosen primary air shutter (Fig. 39) and adjust to a minimum opening of 5⁄8 inch.
5. Retighten primary air shutter and reinstall access panel.
To check ignition of main burners and fan switch operation, move thermostat dial above and below room temperature several times, pausing at least one minute between cycles.
Fig. 37 — Cooling Charging Chart — 48TJ028
24
Protective Devices
COMPRESSOR PROTECTION
Overcurrent — Each compressor has one manual reset, calibrated trip, magnetic circuit breaker. Do not bypass connections or increase the size of the circuit breaker to correct trouble.
Determine the cause and correct it before resetting the breaker.
Overtemperature — Each compressor has an internal protector to protect it against excessively high discharge gas
temperatures.
Crankcase Heater — Each compressor has a 125-watt crankcase heater to prevent absorption of liquid refrigerant by oil
in the crankcase when the compressor is idle. Since power
for the crankcase heaters is drawn from the unit incoming
power, main unit power must be on for the heaters to be
energized.
Fig. 38 — Gas Valve
VIEW
PORT
IMPORTANT: After a prolonged shutdown or service job, energize the crankcase heaters for 24 hours
before starting the compressors.
FLUE BOX
COVER
PRIMARY AIR
SHUTTER
Compressor Lockout — If any of the safeties (high-pressure,
low-pressure, freeze protection thermostat, compressor internal thermostat) trip, or if there is loss of power to the compressors, the cooling lockout (CLO) will lock the compressors off. To reset, manually move the thermostat setting.
EVAPORATOR FAN MOTOR PROTECTION — A manual
reset, calibrated trip, magnetic circuit breaker protects against
overcurrent. Do not bypass connections or increase the size
of the breaker to correct trouble. Determine the cause and
correct it before resetting the breaker.
CONDENSER-FAN MOTOR PROTECTION — Each
condenser-fan motor is internally protected against
overtemperature.
HIGH- AND LOW-PRESSURE SWITCHES — If either
switch trips, or if the compressor overtemperature switch activates, that refrigerant circuit will be automatically locked
out by the CLO. To reset, manually move the thermostat
setting.
FREEZE PROTECTION THERMOSTAT (FPT) — An FPT
is located on the evaporator coil. It detects frost build-up
and turns off the compressor, allowing the coil to clear. Once
the frost has melted, the compressor can be reenergized.
MAIN BURNER
SECTION
Fig. 39 — Typical Heating Section
MAIN BURNER REMOVAL
1. Shut off (field-supplied) manual main gas valve.
2. Shut off power to unit.
3. Remove unit control box access panel, burner section access panel, and center post (Fig. 4-6).
4. Disconnect pilot ignitor and pilot proving sensor leads at
ICP, rollout switch leads at switch, and pilot tube gas connection(s) at the pilot orifice.
5. Disconnect gas connection(s) from between gas valve(s)
and main burners.
6. Remove 2 screws securing burner assembly to base unit.
NOTE: For 48TJE024 and 028 units only: Remove access plate from base rail.
7. Slide burner assembly out of unit.
Relief Devices — All units have relief devices to protect against damage from excessive pressures (i.e., fire). These
devices protect the high and low side.
Control Circuit, 24-V — This control circuit is protected against overcurrent by a 3.2 amp circuit breaker. Breaker
can be reset. If it trips, determine cause of trouble before
resetting.
Replacement Parts — A complete list of replacement
parts may be obtained from any Carrier distributor upon
request.
Filter Drier — Replace whenever refrigerant system is
exposed to atmosphere.
25
LEGEND
Fig. 40 — Typical Wiring Schematic
Fig. 41 — Typical Component Arrangement
AHA
BKR W/AT
C
CB
CC
CH
CLO
CLS
COMP
CR
CT
DM
DU
EQUIP
FPT
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
FU
GND
HPS
HR
HV
I
ICP
IDM
IDR
IFC
—
—
—
—
—
—
—
—
—
—
IFCB
—
Adjustable Heat Anticipator
Breaks with Amp Turns
Contactor, Compressor
Circuit Breaker
Cooling Compensator
Crankcase Heater
Compressor Lockout
Compressor Lockout Switch
Compressor Motor
Control Relay
Current Transformer
Damper Motor
Dummy Terminal
Equipment
Freeze Protection
Thermostat
Fuse
Ground
High-Pressure Switch
Heat Relay
High Voltage
Ignitor
Ignitor Control Pack
Induced-Draft Motor
Induced-Draft Relay
Indoor (Evaporator)
Fan Contactor
Indoor (Evaporator)
Fan Circuit Breaker
IFM
IFR
IP
L
LOR
LPS
LS
MAT
MGV
NEC
OAT
OFC
OFM
PGV
PL
PRI
PS
QT
R
RS
SN
SW
TB
TC
TDR
— Indoor (Evaporator)
Fan Motor
— Indoor (Evaporator)
Fan Relay
— Internal Protector
— Light
— Lockout Relay
— Low-Pressure Switch
— Limit Switch
— Mixed-Air Thermostat
— Main Gas Valve
— National Electrical Code
— Outdoor-Air Thermostat
— Outdoor (Condenser)
Fan Contactor
— Outdoor (Condenser)
Fan Motor
— Pilot Gas Valve
— Plug Assembly
— Primary
— Pressure Switch
— Quadruple Terminal
— Relay
— Rollout Switch
— Sensor
— Switch
— Terminal Block
— Thermostat Cooling
— Time Delay Relay
NOTES:
1. Compressor and fan motors thermally protected; 3-phase motors
protected against primary single-phasing conditions.
2. If any of the original wire furnished must be replaced, it must be
replaced with type 90 C wire or its equivalent.
3. Jumpers are omitted when unit is equipped with economizer.
4. Set thermostat heat anticipator(s):
VOLTAGE
208/230, 575
460
W1
0.98
0.80
TH
— Thermostat Heating
TRAN — Transformer
Terminal (Marked)
Terminal (Unmarked)
Terminal Block
Splice
Splice (Marked)
Splice (Field Supplied)
Factory Wiring
Field Control Wiring
Field Power Wiring
Accessory or Optional Wiring
To Indicate Common Potential Only,
Not To Represent Wiring
5. CB must-trip amps are equal to or less than 140% full load amps.
6. Number(s) indicates the line location of used contacts. A bracket
over (2) numbers signifies a single-pole, double-throw contact. An
underlined number signifies a normally-closed contact. A plain (no
line) number signifies a normally-open contact.
7. The CLO locks out the compressor to prevent short cycling on compressor overload and safety devices. Before replacing CLO, check
these devices.
W2
0.44
0.44
Fig. 40 — Typical Wiring Schematic (48TJ020-028 Shown)
26
Fig. 40 — Typical Wiring Schematic (48TJ020-028 Shown) (cont)
27
Fig. 41 — Typical Component Arrangement (48TJ020-028 Shown)
28
PACKAGED SERVICE TRAINING
Our packaged service training programs provide an excellent way to increase your knowledge of the
equipment discussed in this manual. Product programs cover:
• Unit Familiarization
• Maintenance
• Installation Overview
• Operating Sequence
A large selection of product, theory, and skills programs is available. All programs include a video
cassette and/or slides and a companion booklet. Use these for self teaching or to conduct full training
sessions.
For a free Service Training Material Catalog (STM), call 1-800-962-9212. Ordering instructions are
included.
Copyright 1996 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 111
Catalog No. 564-873
Printed in U.S.A.
Form 48TJ-11SI
Pg 30
4-96
Replaces: 48TJ-7SI
Tab 1a 6a
DATE:
TECHNICIAN:
PRE-START-UP:
M VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT
M LOOSEN ALL SHIPPING HOLDDOWN BOLTS AND BRACKETS PER INSTRUCTIONS
M VERIFY INSTALLATION OF ECONOMIZER HOOD
M VERIFY INSTALLATION OF EXHAUST HOOD
M VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS
M VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT
M CHECK GAS PIPING FOR LEAKS
M CHECK THAT INDOOR-AIR FILTER IS CLEAN AND IN PLACE
M VERIFY THAT UNIT IS LEVEL
M CHECK FAN WHEEL AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SETSCREW
IS TIGHT
M VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED
START-UP
ELECTRICAL
SUPPLY VOLTAGE
L1-L2
L2-L3
L3-L1
COMPRESSOR AMPS — COMPRESSOR NO. 1
L1
L2
L3
— COMPRESSOR NO. 2
(020-028 ONLY)
L1
L2
L3
SUPPLY FAN AMPS
EXHAUST FAN AMPS
TEMPERATURES
OUTDOOR-AIR TEMPERATURE
F DB (Dry Bulb)
RETURN-AIR TEMPERATURE
F DB
COOLING SUPPLY AIR
F
GAS HEAT SUPPLY AIR
F
F
WB (Wet Bulb)
PRESSURES
IN. WG
GAS INLET PRESSURE
IN. WG
STAGE NO. 2
IN. WG
GAS MANIFOLD PRESSURE
STAGE NO. 1
REFRIGERANT SUCTION
CIRCUIT NO. 1
PSIG
CIRCUIT NO. 2
(020-028 ONLY)
PSIG
REFRIGERANT DISCHARGE
CIRCUIT NO. 1
PSIG
CIRCUIT NO. 2
(020-028 ONLY)
PSIG
M VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS ON PAGES 23 AND 24
GENERAL
M ECONOMIZER MINIMUM VENT AND CHANGEOVER SETTINGS TO JOB REQUIREMENTS
Copyright 1996 Carrier Corporation
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 4
PC 111
Catalog No. 564-873
Printed in U.S.A.
Form 48TJ-11SI
Pg CL-1
4-96
Replaces: 48TJ-7SI
Tab 1a 6a
CUT ALONG DOTTED LINE
SERIAL NO.:
CUT ALONG DOTTED LINE
MODEL NO.:
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START-UP CHECKLIST

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