Carrier Air Compressor 50TJ016 028 User Manual

50TJ016-028  
Single-Package Rooftop Units  
Electric Cooling with Electric Heat Option  
Installation, Start-Up and  
Service Instructions  
CONTENTS  
Page  
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . . . . . .1  
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18  
Step 1 — Provide Unit Support . . . . . . . . . . . . . . . . . . . . . .1  
IMPORTANT: Units have high ambient operating lim-  
its. If limits are exceeded, the unit will automatically  
lock the compressor out of operation. Manual reset will  
be required to restart the compressor.  
ROOF CURB  
ALTERNATE UNIT SUPPORT  
Step 2 — Rig and Place Unit. . . . . . . . . . . . . . . . . . . . . . . . .1  
INSTALLATION  
Step 1 — Provide Unit Support  
POSITIONING  
ROOF MOUNT  
ROOF CURB — Assemble and install accessory roof curb or  
horizontal adapter roof curb in accordance with instructions  
shipped with the curb or horizontal adapter. Accessory roof  
curb and horizontal adapter roof curb and information required  
to field fabricate a roof curb or horizontal adapter roof curb are  
shown in Fig. 1 and 2. Install insulation, cant strips, roofing,  
and counter flashing as shown. Ductwork can be secured to  
roof curb before unit is set in place.  
Step 3 — Field Fabricate Ductwork . . . . . . . . . . . . . . . . . .7  
Step 4 — Make Unit Duct Connections . . . . . . . . . . . . . . .7  
Step 5 — Trap Condensate Drain . . . . . . . . . . . . . . . . . . . .7  
Step 6 — Make Electrical Connections . . . . . . . . . . . . . .8  
FIELD POWER SUPPLY  
FIELD CONTROL WIRING  
OPTIONAL NON-FUSED DISCONNECT  
OPTIONAL CONVENIENCE OUTLET  
Step 7 — Make Outdoor-Air Inlet  
IMPORTANT: The gasketing of the unit to the roof curb  
or adapter roof curb is critical for a leak-proof seal.  
Install gasket supplied with the roof curb or adapter roof  
curb as shown in Fig. 1. Improperly applied gasket can  
result in air leaks and poor unit performance.  
Adjustments. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11  
MANUAL OUTDOOR-AIR DAMPER  
OPTIONAL ECONOMI$ER  
Step 8 — Install Outdoor-Air Hood. . . . . . . . . . . . . . . . . .12  
Step 9 — Install All Accessories. . . . . . . . . . . . . . . . . . . .15  
MOTORMASTER® I CONTROL INSTALLATION  
MOTORMASTER III CONTROL INSTALLATION  
Curb or adapter roof curb should be level. This is necessary  
to permit unit drain to function properly. Unit leveling toler-  
Step 10 — Install Humidistat for Optional  
MoistureMiser Dehumidification Package . . . . . . . . .16  
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18-24  
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24-31  
TROUBLESHOOTING. . . . . . . . . . . . . . . . . . . . . . . . . . . . 32,33  
START-UP CHECKLIST . . . . . . . . . . . . . . . . . . . . . . . . . . CL-1  
1
ance is /16 in. per linear ft in any direction. Refer to Accesso-  
ry Roof Curb or Horizontal Adapter Roof Curb Installation In-  
structions for additional information as required.  
ALTERNATE UNIT SUPPORT — When the curb or adapter  
cannot be used, support unit with sleepers using unit curb or  
adapter support area. If sleepers cannot be used, support long  
sides of unit with a minimum of 3 equally spaced 4-in. x 4-in.  
pads on each side.  
SAFETY CONSIDERATIONS  
Installation and servicing air-conditioning equipment can be  
hazardous due to system pressure and electrical components.  
Only trained and qualified service personnel should install, re-  
pair, or service air-conditioning equipment.  
Untrained personnel can perform basic maintenance func-  
tions 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 precau-  
tions in the literature, tags and labels attached to the unit, and  
other safety precautions that may apply.  
Step 2 — Rig and Place Unit — Inspect unit for  
transportation damage. File any claim with transportation  
agency. Keep unit upright, and do not drop. Use spreader bars  
over unit to prevent sling or cable damage. Rollers may be used  
to move unit across a roof. Level by using unit frame as a refer-  
1
ence; leveling tolerance is  
/
16  
in. per linear ft in any direc-  
tion. See Fig. 3 for additional information. Unit 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.  
POSITIONING — Provide clearance around and above unit  
for airflow, safety, and service access (Fig. 4 and 5).  
Do not install unit in an indoor location. Do not locate air in-  
lets near exhaust vents or other sources of contaminated air.  
Follow all safety codes. Wear safety glasses and work  
gloves. Use quenching cloth for unbrazing operations. Have  
fire extinguishers available for all brazing operations.  
Although unit is weatherproof, guard against water from  
higher level runoff and overhangs.  
ROOF MOUNT — Check building codes for weight distribu-  
tion requirements.  
Before performing service or maintenance operations on  
unit, turn off main power switch to unit. Electrical shock  
could cause personal injury.  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
PC 111 Catalog No. 535-034 Printed in U.S.A. Form 50TJ-17SI Pg 1 2-01 Replaces: 50TJ-14SI  
Book 1  
Tab 1b  
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DIMENSIONS  
MAXIMUM  
UNIT  
50TJ  
SHIPPING WEIGHT  
A
B
Lb  
Kg  
703  
748  
771  
839  
Ft-in.  
mm Ft-in. mm  
016  
020  
024  
028  
1550  
1650  
1700  
1850  
6-111/2 2121 4- 0 1219  
6-111/2 2121 3-10 1168  
6-111/2 2121 3- 7 1092  
6-111/2 2121 3- 5 1041  
NOTE: For preassembled horizontal adapter roof curb part no.  
CRRFCURB013A00, the accessory kit includes a factory-designed,  
high-static, transition duct. For horizontal curb part no.  
CRRFCURB012A00, a field-supplied transition duct is required.  
NOTES:  
Fig. 2 — Horizontal Adapter Roof Curb  
and Roof Curb  
1. Dimensions in ( ) are in millimeters.  
2. Refer to Fig. 4 and 5 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.  
5. Weights do not include optional EconoMi$er. See Fig. 4 and 5 for  
EconoMi$er weight. See Table 1 for MoistureMiser weight.  
6. Weights given are for aluminum evaporator and condenser coil  
plate fins.  
All panels must be in place when rigging.  
Fig. 3 — Rigging Details  
3
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4
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5
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Table 1 — Physical Data  
016  
208/230, 460 v  
UNIT 50TJ  
NOMINAL CAPACITY (tons)  
OPERATING WEIGHT  
EconoMi$er  
020  
024  
028  
575 v  
15  
1550  
80  
18  
1650  
80  
20  
1700  
80  
25  
1850  
80  
MoistureMiser Dehumidification  
Package  
40  
40  
40  
40  
COMPRESSOR/MANUFACTURER  
Scroll, Copeland  
1...ZR108KC,  
1...ZR94KC  
55, 45  
1...ZR125KC,  
1...ZR108KC  
55, 45  
1...ZR16M3,  
1...ZR125KC  
60, 40  
Quantity...Model (Ckt 1, Ckt 2)  
2...ZR94KC  
50, 50  
2
Capacity Stages (%)  
Number of Refrigerant Circuits  
Oil (oz) (Ckt 1, Ckt 2)  
2
2
2
81, 81  
106, 81  
106,106  
136, 106  
REFRIGERANT TYPE  
Expansion Device  
Operating Charge (lb-oz)  
Circuit 1*  
R-22  
TXV  
10-10  
10-10  
15-5  
12-3  
16-0  
13-6  
20-13  
13- 0  
Circuit 2  
CONDENSER COIL  
Cross-Hatched 3/8-in. Copper Tubes, Aluminum Lanced,  
Aluminum Pre-Coated, or Copper Plate Fins  
Rows...Fins/in.  
Total Face Area (sq ft)  
2...17  
21.7  
3...15  
21.7  
3...15  
21.7  
4...15  
21.7  
CONDENSER FAN  
Nominal Cfm  
Propeller Type  
10,500  
3...22  
10,500  
3...22  
14,200  
2...30  
14,200  
2...30  
Quantity...Diameter (in.)  
Motor Hp...Rpm  
1/2...1050  
1100  
1/2...1050  
1100  
1...1075  
3400  
1...1075  
3400  
Watts Input (Total)  
EVAPORATOR COIL  
Cross-Hatched 3/8-in. Copper Tubes, Aluminum Lanced or  
Copper Plate Fins, Face Split  
Rows...Fins/in.  
Total Face Area (sq ft)  
2...17  
17.5  
3...15  
17.5  
3...15  
17.5  
4...15  
17.5  
EVAPORATOR FAN  
Quantity...Size (in.)  
Type Drive  
Centrifugal Type  
2...10 x 10  
2...10 x 10  
Belt  
2...12 x 12  
Belt  
2...12 x 12  
Belt  
2...12 x 12  
Belt  
6000  
3.7  
Belt  
Nominal Cfm  
6000  
7200  
5
8000  
10,000  
Motor Hp  
Motor Nominal Rpm  
3.0  
1725  
7.5  
1745  
10  
1725  
1745  
1740  
8.7 [208/230, 575 v]  
9.5 [460 v]  
213T  
10.2 [208/230, 575 v]  
Maximum Continuous Bhp  
4.25  
3.45  
5.90  
11.8 [380, 460 v]  
215T  
Motor Frame Size  
Nominal Rpm High/Low  
Fan r/s Range  
56H  
56H  
184T  
Low-Medium Static  
High Static  
891-1179  
1227-1550  
Ball  
1159-1429  
910-1095  
1069-1287  
Ball  
1002-1225  
1193-1458  
Ball  
1066-1283  
1332-1550  
Ball  
Motor Bearing Type  
Ball  
Maximum Allowable Rpm  
Motor Pulley Pitch Diameter  
Min/Max (in.)  
1550  
1550  
4.3/5.3  
1550  
1550  
1550  
Low-Medium Static  
High Static  
3.1/4.1  
4.9/5.9  
4.9/5.9  
11/8  
9.4  
8.0  
5.4/6.6  
5.4/6.6  
13/8  
4.9/5.9  
4.9/5.9  
13/8  
3.7/4.7  
7
7
Nominal Motor Shaft Diameter (in.)  
Fan Pulley Pitch Diameter (in.)  
/
/
8
8
Low-Medium Static  
High Static  
6.0  
5.2  
6.4  
9.4  
8.0  
7.9  
6.4  
Nominal Fan Shaft Diameter (in.)  
Belt, Quantity...Type...Length (in.)  
13/16  
13/16  
17/16  
17/16  
17/16  
Low-Medium Static  
High Static  
1...BX...42  
1...BX...42  
13.5-15.5  
48  
1...BX...45  
1...BX...50  
1...BX...48  
13.3-14.8  
37  
1...BX...53  
1...BX...50  
14.6-15.4  
37  
2...BX...50  
2...BX...47  
14.6-15.4  
36  
Pulley Center Line Distance (in.)  
Speed Change per Full Turn of  
Movable Pulley Flange (rpm)  
Movable Pulley Maximum Full Turns  
From Closed Position  
Factory Speed  
Factory Speed Setting (rpm  
13.5-15.5  
44  
Low-Medium Static  
High Static  
55  
34  
44  
45  
6
3.5  
1035  
1389  
13/16  
6
3.5  
6
3.5  
1002  
1178  
17/16  
6
3.5  
1120  
1328  
17/16  
6
3.5  
1182  
1470  
17/16  
Low-Medium Static  
High Static  
1296  
Fan Shaft Diameter at Pulley (in.)  
13/16  
HIGH-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto)  
426  
320  
LOW-PRESSURE SWITCH (psig)  
Cutout  
Reset (Auto)  
27  
44  
FREEZE PROTECTION THERMOSTAT (F)  
Opens  
Closes  
30  
45  
5
5
OUTDOOR-AIR INLET SCREENS  
Quantity...Size (in.)  
Cleanable  
2...20 x 25 x 1  
1...20 x 20 x 1  
RETURN-AIR FILTERS  
Quantity...Size (in.)  
Throwaway†  
4...20 x 20 x 2  
4...16 x 20 x 2  
POWER EXHAUST  
1/2 Hp, 208/230-460 v Motor Direct Drive, Propeller-Fan (Factory-Wired for 460 v)  
LEGEND  
†The 50TJ028 units 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).  
Bhp  
TXV  
Brake Horsepower  
Thermostatic Expansion Valve  
NOTE: The 50TJ016-028 units have a low-pressure switch (standard) located  
on the suction side.  
*Circuit 1 uses the lower portion of condenser coil and lower portion of evap-  
orator coils; and Circuit 2 uses the upper portion of both coils.  
6
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Step 3 — Field Fabricate Ductwork — Secure all  
ducts to building structure. Use flexible duct connectors be-  
tween 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 in-  
sulated and covered with a vapor barrier.  
Step 4 — Make Unit Duct Connections — Unit  
is shipped for through-the-bottom duct connections. Ductwork  
openings are shown in Fig. 6. Field-fabricated concentric duct-  
work may be connected as shown in Fig. 7 and 8. Attach all  
ductwork to roof curb and roof curb basepans. Refer to installa-  
tion instructions shipped with accessory roof curb for more  
information.  
The 50TJ units with electric heat require a 1-in. clearance  
for the first 24 in. of ductwork.  
Step 5 — Trap Condensate Drain — See Fig. 4, 5,  
and 9 for drain location. Plug is provided in drain hole and  
3
must be removed when unit is operating. One /4-in. half-  
Outlet grilles must not lie directly below unit discharge.  
coupling is provided inside unit evaporator section for conden-  
NOTE: A 90-degree elbow must be provided in the ductwork  
to comply with UL (Underwriters’ Laboratories) codes for use  
with electric heat.  
sate drain connection. An 81/2 in. x 3/4-in. diameter nipple and a  
3
2-in. x /4-in. diameter pipe nipple are coupled to standard  
3/4-in. diameter elbows to provide a straight path down through  
holes in unit base rails (see Fig. 10). A trap at least 4-in. deep  
must be used.  
For vertical supply and return units, tools or parts could  
drop into ductwork and cause an injury. Install a 90 degree  
turn in the return ductwork between the unit and the condi-  
tioned space. If a 90 degree elbow cannot be installed, then  
a grille of sufficient strength and density should be installed  
to prevent objects from falling into the conditioned space.  
Due to electric heater, supply duct will require 90 degree  
elbow.  
Shaded area indicates block-off panels.  
NOTE: Dimensions A, A′, and B, Bare obtained from field-supplied  
ceiling diffuser.  
Fig. 8 — Concentric Duct Details  
NOTE: Do not drill in this area; damage to basepan may result in  
water leak.  
Fig. 6 — Air Distribution — Thru-the-Bottom  
(50TJ020-028 Shown)  
3/4" FPT DRAIN  
CONNECTION  
1-3/8"  
DRAIN HOLES  
Fig. 9 — Condensate Drain Details  
(50TJ016,020 Shown)  
NOTE: Do not drill in this area; damage to basepan may result in  
water leak.  
Fig. 7 — Concentric Duct Air Distribution  
(50TJ020-028 Shown)  
7
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IMPORTANT: If the supply voltage phase imbalance is  
more than 2%, contact your local electric utility com-  
pany immediately.  
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 the installation in-  
structions included with the accessory. Locate thermostat as-  
sembly on a solid wall in the conditioned space to sense aver-  
age temperature.  
Route thermostat cable or equivalent single leads of no. 18  
AWG (American Wire Gage) colored wire from subbase termi-  
nals through conduit in unit to low-voltage connections as  
shown on unit label wiring diagram and in Fig. 12.  
NOTE: For wire runs up to 50 ft, use no. 18 AWG insulated  
wire (35 C minimum). For 50 to 75 ft, use no. 16 AWG insu-  
lated wire (35 C minimum). For over 75 ft, use no. 14 AWG  
insulated wire (35 C minimum). All wire larger than no. 18  
AWG cannot be directly connected to the thermostat and will  
require a junction box and splice at the thermostat.  
Fig. 10 — Make Electrical Connections  
Step 6 — Make Electrical Connections  
FIELD POWER SUPPLY — Unit is factory wired for volt-  
age shown on nameplate.  
When installing units, provide a disconnect, per NEC  
(National Electrical Code) requirements, of adequate size  
(Table 2).  
All field wiring must comply with NEC and local  
requirements.  
Route power lines through control box access panel or unit  
basepan (Fig. 4 and 5) to connections as shown on unit wiring  
diagram and Fig. 11.  
Set heat anticipator settings as indicated in Table 3. Settings  
may be changed slightly to provide a greater degree of comfort  
for a particular installation.  
Operating voltage to compressor must be within voltage  
range indicated on unit nameplate. On 3-phase units, voltages  
between phases must be balanced within 2% and the current  
must be balanced within 10%.  
The correct power phasing is critical in the operation of the  
scroll compressors. An incorrect phasing will cause the  
compressor to rotate in the wrong direction. This may lead  
to premature compressor failure.  
Use the following formula to determine the percentage of  
voltage imbalance.  
Percentage of Voltage Imbalance  
TB1 MAXIMUM WIRE SIZE  
max voltage deviation from average voltage  
= 100 x  
VOLTAGE  
460  
UNIT  
50TJ  
All  
average voltage  
208/230,380  
575  
EXAMPLE: Supply voltage is 460-3-60.  
350 kcmil  
2/0  
2/0  
AB = 452 v  
BC = 464 v  
AC = 455 v  
LEGEND  
EQUIP — Equipment  
GND — Ground  
kcmil — Thousand Circular Mils  
455 + 464 + 455  
NEC  
TB  
National Electrical Code  
Terminal Block  
Average Voltage =  
3
Fig. 11 — Field Power Wiring Connections  
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 voltage imbalance:  
THERMOSTAT ASSEMBLY  
REMOVABLE JUMPER  
L
RC  
Y1  
Y1  
Y2  
Y2  
W1  
W1  
G
G
C
C
X
X
RH  
W2  
W2  
R
7
Percentage of Voltage Imbalance = 100 x  
457  
= 1.53%  
UNIT LOW-VOLTAGE CONNECTIONS  
This amount of phase imbalance is satisfactory as it is be-  
low the maximum allowable 2%.  
Fig. 12 — Field Control Thermostat Wiring  
8
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Table 2 — Electrical Data  
NOMINAL  
VOLTAGE  
(3 Ph,  
COMPRESSOR  
No. 1 No. 2  
VOLTAGE  
RANGE  
POWER  
ELECTRIC  
HEAT*  
POWER  
SUPPLY  
OFM  
IFM  
FLA  
UNIT  
50TJ  
EXHAUST  
Min Max RLA LRA RLA LRA Qty Hp FLA (ea) Hp  
FLA LRA  
kW  
FLA  
MCA MOCP†  
60 Hz)  
81/81 100/100  
85/86 110/110  
4.6 18.8  
26/34  
71/82 102/116 110/125  
71/82 108/122 110/125  
4.6 18.8 26/34  
208/230 187 253 28.8 195 28.8 195  
3
3
0.5  
0.5  
1.7  
1.7  
3.7 10.5/11.0  
42/56 117/135 159/149 175/175  
4.6 18.8 42/56 117/135 165/155 175/175  
56/75** 156/180 169/194 200/225  
4.6 18.8 56/75** 156/180 175/200 200/225  
43  
45  
50  
60  
2.3 6.0  
20  
20  
30  
30  
43  
46  
50  
60  
380  
342 418 15.0 123 15.0 123  
3.7  
3.9  
2.3 6.0  
016  
(15 Tons)  
35  
35  
52  
52  
70  
73  
80  
80  
2.3 6.0  
40  
43  
50  
50  
2.3 6.0  
32  
32  
39  
39  
55  
58  
60  
60  
2.3 6.0  
460  
575  
414 508 14.7 95 14.7 95  
3
3
3
0.5  
0.5  
0.5  
0.8  
0.75  
1.7  
3.7  
3.0  
4.8  
3.9  
55  
55  
80**  
80**  
50**  
50**  
66  
66  
96  
96  
48  
48  
72  
75  
102  
105  
30  
32  
67  
70  
80  
80  
110  
110  
40  
40  
70  
70  
2.3 6.0  
2.3 6.0  
2.1 4.8  
518 633 10.8 80 10.8 80  
2.1 4.8  
26/34  
87/87 110/110  
92/92 110/110  
4.6 18.8  
71/82 109/122 110/125  
71/82 114/128 125/150  
4.6 18.8 26/34  
208/230 187 253 30.1 225 28.8 195  
5.0 15.8/15.8  
42/56 117/135 166/155 175/175  
4.8 18.8 42/56 117/135 172/161 175/175  
56/75** 156/180 176/200 200/225  
4.6 18.8 56/75** 156/180 182/206 200/225  
020  
(18 Tons)  
44  
47  
50  
60  
2.3 6.0  
32  
32  
39  
39  
59  
61  
60  
70  
2.3 6.0  
460  
575  
414 508 15.5 114 14.7 95  
518 633 12.1 80 10.8 80  
3
3
2
0.5  
0.5  
1
0.8  
0.75  
6.6  
5.0  
5.0  
7.9  
6.0  
55  
55  
80**  
80**  
66  
66  
96  
96  
76  
79  
106  
109  
34  
36  
90  
90  
125  
125  
40  
40  
2.3 6.0  
2.3 6.0  
2.1 4.8  
116/116 150/150  
120/120 150/150  
4.6 18.8  
26/34  
71/82 120/134 150/150  
71/82 126/140 150/150  
4.6 18.8 26/34  
208/230 187 253 37.8 239 30.1 225  
7.5 25.0/25.0  
42/56 117/135 178/166 200/175  
4.6 18.8 42/56 117/135 183/172 200/175  
56/75** 156/180 187/211 200/225  
4.6 18.8 56/75** 156/180 193/217 200/225  
66  
68  
80  
80  
2.3 6.0  
20  
20  
35  
35  
30  
30  
52  
52  
66  
68  
84  
87  
80  
80  
90  
90  
380  
342 418 21.2 145 16.7 140  
2
1
3.9  
7.5  
15.0  
024  
(20 Tons)  
2.3 6.0  
2.3 6.0  
57  
59  
70  
70  
2.3 6.0  
32  
32  
39  
39  
65  
68  
70  
70  
2.3 6.0  
460  
575  
414 508 17.2 125 15.5 114  
518 633 12.4 80 12.1 80  
2
2
1
1
3.3  
3.4  
7.5  
7.5  
13.0  
10.0  
55  
55  
80**  
80**  
66  
66  
96  
96  
82  
85  
112  
115  
44  
46  
90  
90  
125  
125  
50  
50  
2.3 6.0  
2.3 6.0  
2.1 4.8  
9
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Table 2 — Electrical Data (cont)  
NOMINAL  
VOLTAGE  
(3 Ph,  
COMPRESSOR  
No. 1 No. 2  
VOLTAGE  
RANGE  
POWER  
ELECTRIC  
HEAT*  
POWER  
SUPPLY  
OFM  
IFM  
FLA  
UNIT  
50TJ  
EXHAUST  
Min Max RLA LRA RLA LRA Qty Hp FLA (ea) Hp  
FLA LRA  
kW  
FLA  
MCA MOCP†  
60 Hz)  
130/130 150/150  
135/135 175/175  
4.6 18.8  
26/34  
71/82 130/138 150/150  
71/82 135/143 175/175  
4.6 18.8 26/34  
208/230 187 253 41.0 350 37.8 239  
2
2
1
1
6.6  
3.9  
10.0 28.0/28.0  
42/56 117/135 181/170 200/175  
4.6 18.8 42/56 117/135 187/176 200/200  
-
56/75** 156/180 191/215 200/225  
4.6 18.8 56/75** 156/180 197/221 200/225  
73  
76  
90  
90  
2.3 6.0  
20  
20  
30  
30  
73  
76  
90  
90  
380  
342 418 21.8 151 21.2 145  
10.0  
17.0  
028  
2.3 6.0  
(25 Tons)  
35  
35  
52  
52  
87  
90  
90  
90  
2.3 6.0  
66  
68  
80  
80  
2.3 6.0  
32  
32  
39  
39  
67  
70  
80  
80  
2.3 6.0  
460  
575  
414 508 21.8 158 17.2 125  
518 633 17.3 125 12.4 80  
2
2
1
1
2.8  
3.4  
10.0  
10.0  
14.6  
13.0  
55  
55  
80**  
80**  
66  
66  
96  
96  
84  
87  
114  
117  
54  
56  
90  
2.3 6.0  
100  
125  
125  
70  
70  
2.3 6.0  
2.1 4.8  
LEGEND  
FLA — Full Load Amps  
Example: Supply voltage is 460-3-60.  
AB = 452 v  
BC = 464 v  
AC = 455 v  
HACR — Heating, Air Conditioning and Refrigeration  
IFM — Indoor (Evaporator) Fan Motor  
LRA — Locked Rotor Amps  
MCA — Minimum Circuit Amps  
452 + 464 + 455  
3
Average Voltage =  
MOCP— Maximum Overcurrent Protection  
NEC — National Electrical Code  
OFM — Outdoor (Condenser) Fan Motor  
RLA — Rated Load Amps  
1371  
3
=
*Heater capacity (kW) is based on heater voltage of 208 v, 240 v,  
380 v, 480 v, and 575 v. Heaters are rated at 240 v, 380 v, 480 v, or  
600 v. If power distribution voltage to unit varies from rated heater  
voltage, heater kW will vary accordingly.  
= 457  
Determine maximum deviation from average voltage.  
(AB) 457 452 = 5 v  
(BC) 464 457 = 7 v  
Fuse or HACR circuit breaker.  
(AC) 457 455 = 2 v  
**Heaters are field installed only.  
NOTES:  
Maximum deviation is 7 v.  
1. In compliance with NEC requirements for multimotor and combi-  
nation load equipment (refer to NEC Articles 430 and 440), the  
overcurrent protective device for the unit shall be fuse or HACR  
breaker. Canadian units may be fuse or circuit breaker.  
2. Unbalanced 3-Phase Supply Voltage  
Determine percent of voltage imbalance.  
7
% Voltage Imbalance = 100 x  
457  
= 1.53%  
Never operate a motor where a phase imbalance in supply volt-  
age is greater than 2%. Use the following formula to determine  
the percent of voltage imbalance.  
This amount of phase imbalance is satisfactory as it is below the  
maximum allowable 2%.  
% Voltage Imbalance  
IMPORTANT: If the supply voltage phase imbalance is  
more than 2%, contact your local electric utility company  
immediately.  
max voltage deviation from average voltage  
= 100 x  
average voltage  
3. MCA calculation for units with electric heaters over 50 kW =  
(1.25 x IFM amps) + (1.00 x heater FLA).  
10  
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OPTIONAL NON-FUSED DISCONNECT — On units with  
the optional non-fused disconnect, incoming power will be  
wired into the disconnect switch. Refer to Fig. 13 for wiring  
for 100 and 200 amp disconnect switches. Units with an  
MOCP under 100 will use the 100 amp disconnect switch.  
Units with an MOCP over 100 will use the 200 amp discon-  
nect switch. Refer to the applicable disconnect wiring diagram.  
To prevent breakage during shipping, the disconnect han-  
dle and shaft are shipped and packaged inside the unit control  
box. Install the disconnect handle before unit operation. To in-  
stall the handle and shaft, perform the following procedure:  
1. Open the control box door and remove the handle and  
shaft from shipping location.  
2. Loosen the Allen bolt located on the disconnect switch.  
The bolt is located on the square hole and is used to hold  
the shaft in place. The shaft cannot be inserted until the  
Allen bolt is moved.  
Step 7 — Make Outdoor-Air Inlet Adjustments  
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. 14).  
OPTIONAL ECONOMI$ER  
EconoMi$er Motor Control Module (Fig. 15-17) — Set the  
ECONSP dial to the ‘‘D’’ setting (Fig. 16). The control module  
is located on the EconoMi$er motor. See Fig. 15 and 17.  
Damper Vent Position Setting  
1. Set fan switch at ON position (continuous fan operation)  
and close night switch if used.  
2. Set system selector switch to OFF position.  
3. Insert the disconnect shaft into the square hole on the dis-  
connect switch. The end of the shaft is specially cut and  
the shaft can only be inserted in the correct orientation.  
3. Turn Min Pos (%) dial slowly until dampers assume de-  
sired vent position. Do not manually operate EconoMi$er  
motor since damage to motor will result.  
4. Tighten the Allen bolt to lock the shaft into position.  
5. Close the control box door.  
6. Attach the handle to the external access door with the two  
screws provided. When the handle is in the ON position,  
the handle will be vertical. When the handle is in the OFF  
position, the handle will be horizontal.  
7. Turn the handle to the OFF position and close the door.  
The handle should fit over the end of the shaft when the  
door is closed.  
8. The handle must be in the OFF position to open the con-  
trol box door.  
OPTIONAL CONVENIENCE OUTLET — On units with  
optional convenience outlet, a 115-v GFI (ground fault inter-  
rupt) convenience outlet receptacle is provided for field wiring.  
7
Field wiring should be run through the /8-in. knockout pro-  
Fig. 14 — 25% Outdoor-Air Section Details  
vided in the basepan near the return air opening.  
6T3 4T2 2T1 LOAD  
CONTROL  
MODULE  
5L3 3L2 1L1 LINE  
ACTUATOR  
ECONOMI$ER  
NOTE: The disconnect takes the place of TB-1 as shown on the unit  
wiring diagram label and the component arrangement label.  
Fig. 15 — EconoMi$er Damper Assembly  
— End View  
Fig. 13 — Optional Non-Fused Disconnect Wiring  
11  
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Table 3 — Heat Anticipator Settings  
5. Loosen sheet metal screws for base unit top panel located  
above outdoor-air inlet opening, and remove screws for  
hood side panels located on the sides of the outdoor-air  
inlet opening.  
6. Match notches in hood top panel to unit top panel screws.  
Insert hood flange between unit 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 cre-  
ated by lower filter retainer and filter support bracket.  
UNIT  
50TJ  
UNIT  
VOLTAGES  
kW*  
STAGE 1  
STAGE 2  
26/34  
42/56  
56/75  
.40  
.66  
.66  
.66  
.40  
.66  
.40  
.66  
.40  
.66  
.66  
.66  
208/230-3-60  
20  
35  
32  
55  
80  
50  
.40  
.40  
.40  
.40  
.66  
.66  
380-3-60  
460-3-60  
575-3-60  
016-028  
9. Attach remaining short section of filter support bracket.  
*Heater kW is based on heater voltage of 208 v, 240 v, 380 v, 480 v,  
and 575 v.  
OUTDOOR AIR ENTHALPY SENSOR INSTALLA-  
TION — Perform the following procedure to install the out-  
door air enthalpy sensor (part no. CROUTENT001A00).  
1. Remove the outdoor air temperature sensor cover. See  
Fig. 21. Save cover and screws.  
2. Disconnect the wiring from the installed outdoor air tem-  
perature sensor. See Fig. 22.  
1
3. Use a /4-in. nut driver to remove the 2 screws securing  
the outdoor air temperature sensor to the sheet metal.  
4. Mount the outdoor air enthalpy sensor in the outdoor air  
temperature sensor location using the screws removed in  
Step 3.  
5. Connect the outdoor air enthalpy sensor wiring harness to  
the EconoMi$er control module and sensor.  
Fig. 16 — EconoMi$er Control Module  
Adjustment Potentiometers  
6. Re-install sensor cover saved from Step 1.  
RETURN AIR TEMPERATURE SENSOR OR RETURN  
AIR ENTHALPY SENSOR INSTALLATION — Perform the  
following procedure to install the return air temperature sensor  
(part no. CRRETTMP001A00) or return air enthalpy sensor  
(part no. CRRETENT001A00).  
1. Attach the sensor to the mounting bracket using 2 self-  
tapping 1/2-in. screws provided.  
2. Mount the bracket to the inside of the return air opening  
1
flange using a /4-in. nut driver and 2 no. 6 sheet metal  
screws.  
NOTE: The sensor must be mounted in an upright position.  
3. Feed the sensor wiring through the bushing in  
EconoMi$er to secure wires.  
4. Route sensor wiring harness from sensor to EconoMi$er  
control module. Secure wiring harness to the original har-  
ness using tie wraps.  
CONTROL MODULE  
ACTUATOR  
Fig. 17 — EconoMi$er Control Module Location  
5. Wire the sensor to the EconoMi$er control module. See  
Fig. 23 and 24.  
Step 8 — Install Outdoor-Air Hood — The same  
type of factory-installed hood is used on units with 25% air  
ventilation and units with an EconoMi$er.  
NOTE: The hood top panel, upper and lower filter retainers,  
hood drain pan, baffle (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 all other hardware are in a package located  
inside the return-air filter access panel (Fig. 18).  
1. Attach seal strip to upper filter retainer. See Fig. 19.  
2. Assemble hood top panel and side panels, upper filter re-  
tainer, and hood drain pan (Fig. 20).  
3. Secure lower filter retainer and long section of filter sup-  
port bracket to unit. See Fig. 20. Leave screws loose on  
028 units.  
4. Slide baffle (size 028 unit) behind lower filter retainer and  
tighten screws.  
Fig. 18 — Outdoor-Air Hood Component Location  
12  
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OUTSIDE AIR SENSOR  
SENSOR  
COVER  
Fig. 19 — Seal Strip Location  
(Air Hood Cross-Sectional View)  
BAFFLE (028 ONLY)  
Fig. 21 — Outdoor-Air Sensor Location  
MOUNTING SCREW  
LOWER FILTER  
RETAINER  
FILTER SUPPORT  
BRACKET  
SENSOR  
WIRING  
CONNECTIONS  
MOUNTING  
SCREW  
HOOD SIDE  
PANELS (2)  
HOOD TOP  
PANEL  
BAFFLE  
(028 ONLY)  
WIRING  
HARNESS  
Fig. 22 — Outdoor-Air Sensor Details  
LOWER  
FILTER  
RETAINER  
Refer to Table 4 to determine the sensors required for each  
strategy.  
FILTER SUPPORT  
BRACKET  
Differential Enthalpy Switchover Strategy — The differen-  
tial enthalpy switchover strategy must be selected manually, if  
required. To enable, press and hold the CONFIG button for 30  
seconds, then release. The LED will flash twice to indicate the  
change of configuration.  
HOOD DRAIN PAN  
UPPER FILTER RETAINER  
NOTE: The outdoor-air hood comes with a baffle which is used on  
028 units only; discard baffle for 016-024 units.  
To return to single enthalpy mode, press and hold the CON-  
FIG button for 30 seconds. The LED will flash once to indicate  
the change of configuration.  
Fig. 20 — Outdoor-Air Hood Details  
COMMISSIONING — The EconoMi$er saves energy when  
it uses outdoor air to provide free cooling instead of mechani-  
cal air conditioning. The EconoMi$er switchover strategy de-  
termines if the outdoor air is suitable for free cooling. The  
EconoMi$er chooses the switchover strategy with the most en-  
ergy savings, provided that the required sensors are connected  
and functioning normally.  
DISCHARGE AIR THERMISTOR (DAT) — The discharge  
air thermistor is factory-mounted on the supply-fan housing in  
the fan section of the unit. The DAT is factory-wired to the  
EconoMi$er Control Module.  
CO2 CONTROL SETUP — If a CO2 sensor is not being  
used, proceed to the next section. If a CO2 sensor is being used,  
perform the following:  
1. Determine the value at which you want the minimum  
position of the dampers to begin opening to allow a  
greater amount of outdoor air to enter. The range is  
800 to 1,400 ppm.  
IMPORTANT: If a sensor stops functioning nor-  
mally (becomes unreliable), the EconoMi$er  
switches to the next best strategy.  
2. Locate the CO2 SP (PPM) potentiometer and adjust to the  
desired set point. See Fig. 16.  
13  
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MECHANICAL COOLING LOCKOUT — Determine the  
outdoor-air temperature at which you want the mechanical  
cooling (compressors) to be disabled. Locate the mechanical  
cooling lockout (MECH CLG LOCKOUT) potentiometer. To  
disable this feature, turn the potentiometer counterclockwise  
(CCW) to the OFF position. Otherwise, set the value between  
10 and 60 F. Mechanical cooling will not operate when the out-  
door air temperature is below this value. See Fig. 16.  
DRY BULB CHANGEOVER SET UP — Determine the dry  
bulb changeover set point from Table 5. The settings are A, B,  
C and D. Locate the ECON SP potentiometer and set the dry  
bulb changeover set point. See Fig. 16. When the OAT is above  
this set point, the damper is limited to minimum position  
setting.  
If a potentiometer fails, its setting will default to the values  
in Table 6.  
Table 4 — EconoMi$er Switchover Control Strategy  
SENSORS REQUIRED  
ECONOMI$ER SWITCHOVER  
STRATEGY  
Outdoor Air Temperature  
Outdoor Air Enthalpy  
Return Air Temperature  
Return Air Enthalpy  
Dry Bulb  
X
Single Enthalpy  
X
X
Differential Temperature  
Differential Enthalpy*  
X
X
X
*Must be selected manually.  
Table 5 — Changeover Set Points  
Table 6 — Default Potentiometer Settings  
POTENTIOMETER  
CO2 SP (PPM)  
MECH CLG LOCKOUT  
ECON SP  
DEFAULT SETTING  
SETTINGS  
Dry Bulb (°F)  
Single Enthalpy* (Btu/lb)  
Differential Temperature*  
F, Not Adjustable)  
Differential Enthalpy*  
(Btu/lb, Not Adjustable)  
A
B
C
D
1,000  
50 F  
D
73  
27  
69  
25  
66  
24  
63  
22  
2
1
2
1
2
1
2
1
MIN POS (%)  
20  
*Field-installed accessory.  
LEGEND  
Common  
COM  
DAT  
DM  
GND  
OAH  
OAT  
POT  
RAH  
RAT  
REM  
Discharge Air Thermistor  
Damper Motor  
Ground  
Outdoor-Air Enthalpy Sensor  
Outdoor-Air Temperature Sensor  
Potentiometer  
Return-Air Enthalpy Sensor  
Return-Air Temperature Sensor  
Remote  
*OAT sensor shipped with economizer option. OAH, RAT, RAH and CO2 are field-installed accessories.  
Fig. 23 — Typical EconoMi$er Sensor Wiring  
14  
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VENTILATION AIR (Minimum Position Set Up) — If ven-  
tilation air is not required, skip this section. If ventilation air is  
required, perform the following:  
1. The indoor fan must be on to set the ventilation air.  
Either put the thermostat in the continuous fan mode or  
jumper the R and G terminals at the rooftop unit con-  
nection board.  
2. Locate the minimum position (MIN POS) potentiometer.  
Turn the potentiometer full CCW to fully close the out-  
door air dampers. Turn the potentiometer gradually  
clockwise (CW) to the desired position. See Fig. 16.  
3. Replace the filter access panel. See Fig. 18. Ensure the fil-  
ter access panel is securely engaged.  
Personal Injury Hazard. Avoid possible injury by keep-  
ing fingers away from damper blades.  
Step 9 — Install All Accessories — After all the  
factory-installed options have been adjusted, install all field-  
installed accessories. Refer to the accessory installation instruc-  
tions included with each accessory.  
MOTORMASTER®  
I
CONTROL INSTALLATION  
(50TJ016 and 020 Only)  
Install Field-Fabricated Wind Baffles — Wind baffles must  
be field-fabricated for all units to ensure proper cooling cycle  
operation at low ambient temperatures. See Fig. 25 for baffle  
details. Use 20-gage, galvanized sheet metal, or similar  
corrosion-resistant metal for baffles. Use field-supplied screws  
to attach baffles to unit. Screws should be 1/4-in. diameter and  
5/8-in. long. Drill required screw holes for mounting baffles.  
4. Calculate the minimum airflow across the EconoMi$er.  
a. Calculate % of outside air using the following  
formula.  
% Outdoor air through EconoMi$er  
Mixture Temp – Return Air Temp  
% Outdoor air =  
Outdoor Temp – Return Air Temp  
b. Multiply total CFM by percentage outdoor air, this  
gives outdoor air volume in CFM.  
To avoid damage to the refrigerant coils and electrical com-  
ponents, use recommended screw sizes only. Use care  
when drilling holes.  
Unoccupied Control  
(Part number on the control  
must be AD-DME1701-1  
or AD-DME1711-1.)  
Outdoor Air Enthalpy  
CROUTENT001A00  
Unoccupied  
Contact  
470 ohm  
5 watt  
Resistor  
T
Violet  
O
C
O
M
U
T
T
PW  
24 VAC must be present  
on BI for the system to be  
unoccupied.  
Tan  
OAT  
COM  
OAH  
+15V  
RAT  
COM  
RAH  
+15V  
Violet  
White  
Red  
Return Air Enthalpy  
CRRETENT001A00  
Tan  
Violet  
Violet  
White  
Red  
T
O
CO2 Sensors:  
33ZCSENCO2  
C
O
M
U
T
T
PW  
2 to 10 VDC at  
0 to 2000 ppm  
CO (+)  
2
CO  
2
COM  
DAT  
COM  
REM  
POT  
COM  
LED  
Remote  
Minimum Position  
Line  
Voltage  
1k ohm Potentiometer  
COM  
20 mA LED  
Remote  
LED  
Field-supplied Wiring  
Wiring Included  
Fig. 24 — Typical EconoMi$er Sensor Wiring  
15  
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Install Motormaster I Controls — Only one Motormaster I  
control is required per unit. The Motormaster I control must be  
used in conjunction with the Accessory 0° F Low Ambient Kit  
(purchased separately). The Motormaster I device controls out-  
door fan no. 1 while outdoor fans no. 2 and 3 are sequenced off  
by the Accessory 0° F Low Ambient Kit.  
Accessory 0° F Low Ambient Kit — Install the Accessory 0° F  
Low Ambient Kit per instruction supplied with accessory.  
Sensor Assembly — Install the sensor assembly in the location  
shown in Fig. 26.  
Motor Mount — To ensure proper fan height, replace the exist-  
ing motor mount with the new motor mount provided with  
accessory.  
Transformer (460 and 575-v Units Only) — On 460 and  
575-volt units a transformer is required. The transformer is  
provided with the accessory and must be field-installed.  
Motormaster I Control — Recommended mounting location is  
on the inside of the panel to the left of the control box. The  
control should be mounted on the inside of the panel, verti-  
cally, with leads protruding from bottom of extrusion.  
MOTORMASTER® III CONTROL INSTALLATION  
(50TJ024 and 028 Only)  
Install Field-Fabricated Wind Baffles — Wind baffles must  
be field-fabricated for all units to ensure proper cooling cycle  
operation at low ambient temperatures. See Fig. 25 for baffle  
details. Use 20-gage, galvanized sheet metal, or similar  
corrosion-resistant metal for baffles. Use field-supplied screws  
to attach baffles to unit. Screws should be 1/4-in. diameter and  
5/8-in. long. Drill required screw holes for mounting baffles.  
NOTE: Dimensions in ( ) are in mm.  
Fig. 25 — Wind Baffle Details  
To avoid damage to the refrigerant coils and electrical com-  
ponents, use recommended screw sizes only. Use care  
when drilling holes.  
NOTE: If unit power is supplied through the roof curb and  
basepan of the unit, mount the Motormaster III control on the  
corner post adjacent to the conduit running from the basepan to  
the bottom of the control box.  
Replace Outdoor Motor — Replace outdoor fan motor no. 1  
with motor included in accessory kit. Existing motor is not  
Motormaster® III compatible.  
Install Motormaster III Controls — Only one Motormaster  
III control is required per unit.  
Sensor — Install the sensor for thermistor input control in the  
location shown in Fig. 27. Connect sensor leads to the purple  
and grey control signal leads on the Motormaster III control.  
Signal Selection Switch — Remove the cover of the Motor-  
master III control. Set the switch to accept the thermistor sen-  
sor input signal. Set the frequency to match the unit power sup-  
ply (60 Hz).  
Step 10 — Install Humidistat for Optional  
MoistureMiser Dehumidification Package —  
MositureMiser dehumidification package operation can be  
controlled by field installation of a Carrier-approved humidis-  
tat. To install the humidistat perform the following procedure:  
1. Locate humidistat on a solid interior wall in the condi-  
tioned space. Location should be a well ventilated area  
to sense average humidity.  
2. Route thermostat cable or equivalent single leads of col-  
ored wire from Humidistat terminals through conduit in  
unit to the low voltage connection on the 2-pole terminal  
strip (TB3) as shown in Fig. 28 and Fig. 29.  
Motormaster III Control — Recommended mounting location  
is beneath the control box, mounted to the partition that sepa-  
rates the control box section from the indoor section.  
16  
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SENSOR  
LOCATION  
SENSOR  
LOCATION  
SENSOR  
LOCATION  
SENSOR  
LOCATION  
HAIRPIN END  
HAIRPIN END  
HAIRPIN END  
HAIRPIN END  
50TJ016  
50TJ020  
50TJ024  
50TJ028  
NOTE: All sensors are located on the eighth hairpin up from the  
bottom.  
NOTE: All sensors are located on the eighth hairpin up from the  
bottom.  
Fig. 27 — Motormaster III Sensor Locations  
Fig. 26 — Motormaster® I Sensor Locations  
LEGEND  
LLSV — Liquid Line Solenoid Valve  
LPS  
TB  
Low Pressure Switch  
Terminal Block  
TRAN — Transformer  
Fig. 28 — Typical MoistureMiser Dehumidification Package  
Humidistat Wiring Schematic (460V Unit Shown)  
17  
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1. Connect service gages to suction and discharge pressure  
fittings.  
2. Energize the compressor.  
3. The suction pressure should drop and the discharge pres-  
sure should rise, as is normal on any start-up.  
If the suction pressure does not drop and the discharge pres-  
sure does not rise to normal levels:  
1. Note that the evaporator fan is probably also rotating in  
the wrong direction.  
2. Turn off power to the unit.  
3. Reverse any two of the incoming power leads.  
4. Turn on power to the compressor.  
The suction and discharge pressure levels should now move  
to their normal start-up levels.  
NOTE: When compressors are rotating in the wrong direction,  
the unit will have increased noise levels and will not provide  
heating and cooling.  
Fig. 29 — Typical MoistureMiser Dehumidification  
Package Control Box  
After a few minutes of reverse operation, the scroll com-  
pressor internal overload protection will open, which will acti-  
vate the unit’s lockout and requires a manual reset. Reset is ac-  
complished by turning the thermostat on and off.  
START-UP  
Use the following information and Start-Up Checklist on  
page CL-1 to check out unit PRIOR to start-up.  
Evaporator Fan — Fan belt and variable pulleys are fac-  
tory installed. Remove tape from the fan pulley. See Table 7 for  
Air Quantity Limits. See Tables 8-10 for Fan Performance  
data. Be sure that fans rotate in the proper direction. See  
Tables 11-13 for Static Pressure information for accessories  
and options. See Table 14 for fan rpm at various fan motor pul-  
ley settings. To alter fan performance, see Evaporator-Fan Per-  
formance Adjustment section, page 25.  
Unit Preparation — Check that unit has been installed in  
accordance with these installation instructions and all applica-  
ble codes.  
Internal Wiring — Check all electrical connections in  
unit control boxes; tighten as required.  
Crankcase Heater (Size 028 and Units with  
MoistureMiser Dehumidification Package  
Only) — Heater is energized as long as there is power to unit  
and compressor is not operating.  
Table 7 — Air Quantity Limits  
UNIT  
MINIMUM CFM  
MAXIMUM CFM  
50TJ  
016  
020  
024  
028  
4500  
5400  
6000  
7000  
7,500  
9,000  
10,000  
11,250  
IMPORTANT: Unit power must be on for 24 hours prior  
to start-up. Otherwise, damage to compressor may  
result.  
Condenser Fans and Motors — Fans and motors  
are factory set. Refer to Condenser-Fan Adjustment section  
(page 26) as required.  
Compressor Mounting — Compressors are internally  
spring mounted. Do not loosen or remove compressor hold-  
down bolts.  
Return-Air Filters — Check that correct filters are in-  
stalled in filter tracks. See Table 1. Do not operate unit without  
return-air filters.  
Refrigerant Service Ports — Each refrigerant sys-  
tem has a total of 3 Schrader-type service gage ports. One port  
is located on the suction line, one on the compressor discharge  
line, and one on the liquid line. In addition Schrader-type  
valves are located underneath the low-pressure switches. Be  
sure that caps on the ports are tight.  
Outdoor-Air Inlet Screens — Outdoor-air inlet screens  
must be in place before operating unit.  
Accessory EconoMi$er Adjustment — Remove fil-  
ter access panel. Check that outdoor-air damper blades are  
closed and return-air damper blades are open.  
EconoMi$er operation and adjustment is described in Base  
Unit Operation and EconoMi$er Adjustment sections  
(pages 23 and 27), respectively.  
Compressor Rotation — It is important to be certain  
the compressors are rotating in the proper direction. To deter-  
mine whether or not compressors are rotating in the proper di-  
rection:  
18  
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Table 8 — Fan Performance — 50TJ016  
50TJ016 (15 TONS)*  
Airflow  
Available External Static Pressure (in. wg)  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
(Cfm)  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
4500  
4800  
5100  
5400  
5700  
6000  
6300  
6600  
6900  
7200  
7500  
684 1.28 1102  
715 1.47 1265  
747 1.67 1442  
779 1.90 1635  
812 2.14 1844  
845 2.40 2068  
878 2.68 2309  
912 2.98 2566  
791 1.49 1283  
817 1.68 1451  
844 1.89 1633  
872 2.12 1831  
901 2.37 2044  
887 1.70 1466  
910 1.90 1638  
977 1.92 1652 1061 2.13 1841 1139 2.36 2034  
997 2.12 1828 1078 2.34 2021 1155 2.57 2217  
934 2.12 1825 1018 2.34 2019 1097 2.57 2216 1171 2.80 2416  
959 2.35 2027 1040 2.58 2226 1117 2.81 2426 1189 3.05 2629  
985 2.60 2245 1063 2.84 2448 1138 3.07 2652 1209 3.31 2858  
931 2.64 2273 1011 2.87 2478 1087 3.11 2685 1160 3.35 2893 1229 3.60 3103  
961 2.92 2518 1039 3.16 2728 1112 3.41 2939 1183 3.65 3151 1250 3.90 3365  
992 3.22 2780 1067 3.47 2994 1138 3.72 3209 1207 3.97 3425 1273 4.22 3642  
946 3.29 2841 1023 3.55 3059 1096 3.80 3277 1165 4.05 3496 1232 4.31 3716  
981 3.63 3133 1055 3.89 3355 1125 4.15 3578  
1016 3.99 3443 1087 4.25 3669  
50TJ016 (15 TONS)* (cont)  
Available External Static Pressure (in. wg)  
1.6 1.8 1.9  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
Airflow  
1.4  
2.0  
(Cfm)  
4500  
4800  
5100  
5400  
5700  
6000  
6300  
6600  
6900  
7200  
7500  
1214 2.59 2230 1285 2.82 2430 1353 3.05 2633 1386 3.17 2736 1418 3.29 2839  
1228 2.80 2417 1297 3.04 2619 1364 3.27 2825 1396 3.40 2928 1428 3.52 3033  
1243 3.04 2618 1311 3.27 2823 1376 3.51 3031 1408 3.64 3136 1439 3.76 3242  
1259 3.29 2835 1326 3.53 3043 1390 3.77 3254 1421 3.90 3360 1452 4.02 3467  
1277 3.56 3067 1342 3.80 3278 1405 4.05 3492 1435 4.17 3600 1466 4.30 3708  
1295 3.84 3316 1359 4.09 3530 1421 4.34 3746  
1315 4.15 3580  
LEGEND  
2. Static pressure losses (i.e., EconoMi$er) must be added to  
external static pressure before entering Fan Performance table.  
3. Interpolation is permissible. Do not extrapolate.  
4. Fan performance is based on wet coils, clean filters, and  
casing losses. See Table 11 for accessory/FIOP static pressure  
information.  
5. Extensive motor and drive testing on these units ensures that  
the full horsepower and watts range of the motor can be utilized  
with confidence. Using your fan motors up to the watts or bhp  
rating shown will not result in nuisance tripping or premature  
motor failure. Unit warranty will not be affected.  
6. Use of a field-supplied motor may affect wiring size. Contact  
your Carrier representative for details.  
Bhp  
FIOP  
Brake Horsepower  
Factory-Installed Option  
Watts — Input Watts to Motor  
*Standard low-medium static drive range is 891 to 1179 rpm (for  
208/230, 380 and 460 v units) or 1159 to 1429 rpm (for 575-v  
units). Alternate high-static drive range is 1227 to 1550 (for 208/  
230, 380, and 460 v units). The alternate high-static drive is not  
available for 50TJ016 575-v units. Other rpms require a field-sup-  
plied drive.  
NOTES:  
1. Maximum continuous bhp is 4.25 (208/230, 380 and 460 v) or  
3.45 (575 v) and the maximum continuous watts are 3775 (208/  
230, 380, and 460 v) or 3065 (575 v). Do not adjust motor rpm  
such that motor maximum bhp and/or watts is exceeded at the  
maximum operating cfm.  
19  
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Table 9 — Fan Performance — 50TJ020 and 024  
50TJ020, 024 (18 and 20 TONS)*  
Available External Static Pressure (in. wg)  
Airflow  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
(Cfm)  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
5,500  
6,000  
6,500  
7,000  
7,500  
8,000  
8,500  
682 1.99 1675  
730 2.38 2005  
778 2.82 2373  
828 3.31 2780  
878 3.84 3227  
928 4.42 3715  
760 2.29 1922  
802 2.68 2257  
846 3.13 2630  
892 3.62 3042  
938 4.15 3494  
832 2.59 2177  
871 2.99 2516  
911 3.44 2893  
901 2.90 2441  
935 3.31 2783  
965 3.22 2712 1027 3.56 2990  
997 3.63 3057 1056 3.97 3337  
972 3.76 3164 1031 4.09 3440 1087 4.43 3722  
953 3.94 3310 1011 4.26 3583 1067 4.59 3863 1121 4.93 4148  
996 4.48 3766 1051 4.81 4043 1105 5.14 4326 1156 5.49 4613  
985 4.74 3986 1040 5.07 4263 1093 5.40 4544 1144 5.74 4830 1194 6.09 5120  
979 5.05 4245 1033 5.38 4521 1085 5.71 4801 1136 6.05 5086 1185 6.39 5375 1232 6.74 5669  
9,000 1030 5.73 4817 1082 6.06 5098 1131 6.40 5382 1180 6.74 5671 1227 7.09 5964 1272 7.44 6260  
9,500 1082 6.46 5433 1131 6.80 5718 1178 7.14 6007 1225 7.49 6299 1270 7.84 6595 1313 8.20 6895  
10,000 1134 7.25 6093 1180 7.59 6382 1226 7.94 6675 1270 8.29 6971 1313 8.65 7271 1356 9.01 7574  
50TJ020, 024 (18 and 20 TONS)* (cont)  
Available External Static Pressure (in. wg)  
Airflow  
1.4  
1.6  
1.8  
1.9  
2.0  
(Cfm)  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
5,500 1086 3.89 3275 1142 4.24 3567 1197  
6,000 1112 4.31 3623 1167 4.66 3915 1219  
6,500 1142 4.77 4010 1194 5.12 4304 1245  
7,000 1173 5.28 4438 1224 5.63 4733 1273  
7,500 1207 5.83 4906 1255 6.19 5203 1302  
8,000 1242 6.44 5415 1289 6.80 5714 1334  
8,500 1279 7.10 5966 1324 7.45 6268 1368  
9,000 1317 7.80 6561 1360 8.16 6865 1403  
9,500 1356 8.56 7198 1398 8.93 7505 1440  
4.59 3864 1223 4.77 4015 1249 4.96 4167  
5.01 4213 1245 5.19 4364 1270 5.37 4516  
5.47 4602 1270 5.65 4754 1294 5.83 4906  
5.98 5033 1296 6.17 5184 1320 6.35 5337  
6.55 5504 1326 6.73 5657 1348 6.91 5810  
7.16 6018 1357 7.34 6171 1379 7.52 6325  
7.82 6573 1389 8.00 6728 1411 8.18 6883  
8.53 7173 1424 8.71 7328 1445 8.90 7484  
9.29 7815 1460 9.48 7972 1480 9.67 8129  
10,000 1397 9.37 7881 1438 9.74 8190 1477 10.11 8503  
LEGEND  
(208/230, 575 v) or 8640 (380, 460 v). Do not adjust motor rpm  
such that motor maximum bhp and/or watts is exceeded at the  
maximum operating cfm.  
Bhp  
Brake Horsepower  
FIOP  
Factory-Installed Option  
2. Static pressure losses (i.e., EconoMi$er) must be added to  
external static pressure before entering Fan Performance table.  
3. Interpolation is permissible. Do not extrapolate.  
4. Fan performance is based on wet coils, clean filters, and casing  
losses. See Table 12 for accessory/FIOP static pressure  
information.  
5. Extensive motor and drive testing on these units ensures that  
the full horsepower and watts range of the motor can be utilized  
with confidence. Using your fan motors up to the watts or bhp  
rating shown will not result in nuisance tripping or premature  
motor failure. Unit warranty will not be affected.  
6. Use of a field-supplied motor may affect wiring size. Contact  
your Carrier representative for details.  
Watts — Input Watts to Motor  
*Standard low-medium static drive range for the 020 size is 910 to  
1095 rpm. Standard low-medium static drive range for the 024 size  
is 1002 to 1225 rpm. Alternate high-static drive range for the  
020 size is 1069 to 1287. Alternate high-static drive range for the  
024 size is 1193 to 1458 rpm. Other rpms require a field-supplied  
drive.  
NOTES:  
1. Maximum continuous bhp for the 020 size is 5.90. Maximum  
continuous bhp for the 024 size is 8.7 (208/230, 575 v) or 9.5  
(380, 460 v). The maximum continuous watts for the 020 size is  
5180. The maximum continuous watts for the 024 size is 7915  
20  
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Table 10 — Fan Performance — 50TJ028  
50TJ028 (25 TONS)*  
Available External Static Pressure (in. wg)  
Airflow  
0.2  
0.4  
0.6  
0.8  
1.0  
1.2  
(Cfm)  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
7,000  
7,500  
8,000  
845 3.26 2693  
896 3.82 3156  
909 3.60 2979  
969 3.96 3272 1028 4.32 3574 1083 4.70 3883 1137 5.08  
4,200  
4,698  
5,243  
5,838  
6,483  
7,179  
7,929  
8,733  
9,594  
956 4.17 3450 1014 4.54 3752 1069 4.91 4060 1123 5.29 4375 1174 5.68  
948 4.43 3667 1005 4.80 3969 1060 5.17 4278 1112 5.56 4593 1163 5.94 4915 1213 6.34  
8,500 1001 5.11 4226 1054 5.49 4537 1106 5.87 4853 1156 6.26 5175 1205 6.66 5504 1253 7.06  
9,000 1053 5.85 4836 1104 6.23 5155 1154 6.63 5478 1202 7.02 5808 1248 7.43 6142 1294 7.84  
9,500 1106 6.65 5498 1155 7.04 5824 1202 7.44 6155 1248 7.85 6492 1293 8.26 6833 1336 8.68  
10,000 1159 7.52 6214 1206 7.92 6547 1251 8.33 6886 1295 8.74 7229 1338 9.16 7577 1380 9.59  
10,500 1213 8.45 6984 1257 8.86 7325 1300 9.28 7671 1342 9.70 8020 1384 10.13 8375 1424 10.56  
11,000 1266 9.45 7810 1309 9.87 8159 1350 10.29 8511 1391 10.73 8868 1431 11.16 9229 1470 11.60  
11,250 1293 9.97 8245 1334 10.40 8597 1375 10.83 8953 1415 11.26 9313 1454 11.70 9677 1493 12.15 10,045  
50TJ028 (25 TONS)* (cont)  
Available External Static Pressure (in. wg)  
Airflow  
1.4  
1.6  
1.8  
(Cfm)  
Rpm Bhp Watts Rpm Bhp Watts Rpm Bhp Watts  
7,000 1189 5.47 4,524 1239 5.87 4,854 1288 4.91 5191  
7,500 1224 6.08 5,026 1272 6.48 5,362 1320 5.56 5703  
8,000 1261 6.75 5,577 1307 7.16 5,917 1353 6.26 6263  
8,500 1299 7.47 6,177 1344 7.89 6,523 1388 7.02 6873  
9,000 1338 8.26 6,828 1382 8.68 7,179 1424 7.85 7534  
9,500 1379 9.11 7,530 1421 9.54 7,887 1462 8.74 8247  
10,000 1421 10.02 8,286 1461 10.46 8,648 1501 9.70 9014  
10,500 1464 11.00 9,096 1503 11.45 9,464 1541 10.73 9835  
11,000 1508 12.05 9,963 1546 12.50 10,336  
11,250 1530 12.60 10,417  
2. Static pressure losses (i.e., EconoMi$er) must be added to  
external static pressure before entering Fan Performance table.  
3. Interpolation is permissible. Do not extrapolate.  
4. Fan performance is based on wet coils, clean filters, and casing  
losses. See Table 12 for accessory/FIOP static pressure  
information.  
5. Extensive motor and drive testing on these units ensures that  
the full horsepower and watts range of the motor can be utilized  
with confidence. Using your fan motors up to the watts or bhp  
rating shown will not result in nuisance tripping or premature  
motor failure. Unit warranty will not be affected.  
6. Use of a field-supplied motor may affect wiring size. Contact  
your Carrier representative for details.  
LEGEND  
Bhp  
Brake Horsepower  
Factory-Installed Option  
Watts — Input Watts to Motor  
FIOP  
*Standard low-medium static drive range is 1066 to 1283 rpm. Alter-  
nate high-static drive range is 1332 to 1550. Other rpms require a  
field-supplied drive.  
NOTES:  
1. Maximum continuous bhp is 10.2 (208/230, 575 v) or 11.8 (380,  
460 v) and the maximum continuous watts are 9510 (208/230,  
575 v) or 11,000 (380, 460 v). Do not adjust motor rpm such  
that motor maximum bhp and/or watts is exceeded at the maxi-  
mum operating cfm.  
21  
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Table 11 — Accessory/FIOP Static Pressure (in. wg) — 50TJ016  
CFM  
COMPONENT  
4500  
0.04  
0.22  
5000  
0.05  
0.26  
6000  
0.07  
0.35  
7200  
0.09  
0.44  
7500  
0.10  
0.46  
EconoMi$er  
Glycol Coil  
Electric Heat (kW)  
20  
0.06  
0.06  
0.06  
0.07  
0.07  
0.09  
0.07  
0.09  
0.09  
0.07  
0.07  
0.07  
0.08  
0.08  
0.10  
0.08  
0.10  
0.10  
0.09  
0.09  
0.09  
0.12  
0.12  
0.15  
0.12  
0.15  
0.15  
0.11  
0.11  
0.11  
0.15  
0.16  
0.20  
0.15  
0.20  
0.20  
0.12  
0.12  
0.12  
0.17  
0.17  
0.21  
0.17  
0.21  
0.21  
26/34  
32  
35  
42/56  
50  
55  
56/75  
80  
LEGEND  
FIOP — Factory-Installed Option  
NOTES:  
1. The static pressure must be added to external static pressure.  
The sum and the evaporator entering-air cfm should then be  
used in conjunction with the Fan Performance tables to deter-  
mine blower rpm and watts.  
2. Heaters are rated at 240 v, 380 v, 480 v, and 600 v.  
Table 12 — Accessory/FIOP Static Pressure (in. wg) — 50TJ020-028  
CFM  
COMPONENT  
5400  
0.06  
0.30  
6000  
0.07  
0.35  
7200  
0.09  
0.44  
9000  
0.11  
0.58  
10,000  
0.12  
0.66  
11,250  
0.14  
0.77  
EconoMi$er  
Glycol Coil  
Electric Heat (kW)  
20, 26/34  
32  
0.08  
0.08  
0.11  
0.11  
0.14  
0.14  
0.09  
0.09  
0.12  
0.12  
0.15  
0.15  
0.11  
0.11  
0.15  
0.15  
0.20  
0.20  
0.15  
0.15  
0.19  
0.19  
0.24  
0.24  
0.17  
0.17  
0.21  
0.21  
0.26  
0.26  
0.20  
0.20  
0.24  
0.24  
0.29  
0.29  
35, 42/56  
55  
56/75  
80  
LEGEND  
FIOP — Factory-Installed Option  
NOTES:  
1. The static pressure must be added to external static pressure.  
The sum and the evaporator entering-air cfm should then be  
used in conjunction with the Fan Performance tables to deter-  
mine blower rpm and watts.  
2. Heaters are rated at 240 v, 380 v, and 480 v. There are no  
575-v heaters.  
Table 13 — MoistureMiser Dehumidification  
Package Static Pressure Drop (in. wg)  
CFM PER TON  
UNIT SIZE  
50TJ  
UNIT NOMINAL  
TONS  
300  
400  
.071  
.102  
.126  
.197  
500  
016  
020  
024  
028  
15  
18  
20  
25  
.040  
.058  
.071  
.111  
.111  
.160  
.197  
.308  
Table 14 — Fan Rpm at Motor Pulley Settings*  
MOTOR PULLEY TURNS OPEN  
UNIT  
50TJ  
1/  
0
1
11/  
2
21/  
3
31/  
4
41/  
5
51/  
2
6
2
2
2
2
2
016 (208/230, 380, 460 v)†  
016 (208/230, 380, 460 v)**  
†† ††  
†† ††  
†† ††  
†† ††  
†† ††  
†† ††  
†† ††  
†† ††  
†† ††  
1179  
1559  
1429  
1095  
1287  
1225  
1458  
1283  
1150  
1522  
1403  
1077  
1265  
1209  
1434  
1269  
1121  
1488  
1376  
1058  
1243  
1187  
1407  
1247  
1551  
1093  
1455  
1349  
1040  
1222  
1165  
1381  
1225  
1524  
1064  
1422  
1323  
1021  
1200  
1143  
1354  
1203  
1497  
1035  
1389  
1296  
1002  
1178  
1120  
1328  
1182  
1470  
1006  
1356  
1269  
984  
1156  
1098  
1301  
1160  
1443  
978  
1323  
1242  
965  
1134  
1076  
1275  
1138  
1415  
949  
920  
1256  
1188  
928  
1091  
1031  
1222  
1095  
1361  
891  
1289  
1215  
947  
1112  
1053  
1248  
1116  
1388  
1227  
1159  
910  
1069  
1002  
1193  
1066  
1332  
016 (575 v)†  
020†  
020**  
024†  
024**  
028†  
028**  
*Approximate fan rpm shown.  
Indicates standard drive package.  
**Indicates alternate drive package.  
††Due to belt and pulley size, pulley cannot be set to this number of  
turns open.  
22  
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FREEZE PROTECTION THERMOSTAT(S) — A freeze  
protection thermostat (FPT) is located on the top and bottom of  
the evaporator coil. It detects frost build-up and turns off the  
compressor, allowing the coil to clear. Once frost has melted,  
the compressor can be reenergized by resetting the compressor  
lockout.  
HEATING, UNITS WITH ECONOMI$ER (If Accessory or  
Optional Heater is Installed) — When the room thermostat  
calls for heat, the heating controls are energized as described in  
the Heating, Units Without EconoMi$er section. The IFM is  
energized and the EconoMi$er damper modulates to the mini-  
mum position. When the thermostat is satisfied, the damper  
modulates closed.  
UNITS WITH MOISTUREMISER DEHUMIDIFICATION  
PACKAGE — When thermostat calls for cooling, terminals G  
and Y1 and/or Y2 and the compressor contactor C1 and/or C2  
are energized. The indoor (evaporator) fan motor (IFM), com-  
pressors, and outdoor (condenser) fan motors (OFM) start. The  
OFMs run continuously while the unit is in cooling. As shipped  
from the factory, both MoistureMiser dehumidification circuits  
are always energized.  
If MoistureMiser circuit modulation is desired, a field-  
installed, wall-mounted humidistat is required. If the Mois-  
tureMiser humidistat is installed and calls for the Mois-  
tureMiser subcooler coil to operate, the humidistat internal  
switch closes. This energizes the 3-way liquid line solenoid  
valve coils (LLSV1 for circuit 1 and LLSV2 for circuit 2) of  
the MoistureMiser circuits, forcing the warm liquid refrigerant  
of the liquid line to enter the subcooler coils. See Fig. 30.  
As the warm liquid passes through the subcooler coils, it is  
exposed to the cold supply airflow coming off the evaporator  
coils and the liquid is further cooled to a temperature approach-  
ing the evaporator coil leaving-air temperature. The state of the  
refrigerant leaving the subcooler coils is a highly subcooled liq-  
uid refrigerant. The liquid then enters a thermostatic expansion  
valve (TXV) where the liquid is dropped to the evaporator  
pressure. The TXVs can throttle the pressure drop of the liquid  
refrigerant and maintain proper conditions at the compressor  
suction valves over a wide range of operating conditions. The  
liquid proceeds to the evaporator coils at a temperature lower  
than normal cooling operation. This lower temperature is what  
increases the latent and sensible capacity of the evaporator  
coils.  
Base Unit Operation  
COOLING, UNITS WITHOUT ECONOMI$ER — 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 evaporator-fan motor,  
compressor no. 1 and condenser fans start. The condenser-fan  
motors run continuously while unit is cooling. If the thermostat  
calls for a second stage of cooling by energizing Y2, compres-  
sor contactor no. 2 (C2) is energized and compressor no. 2  
starts.  
HEATING, UNITS WITHOUT ECONOMI$ER (If Acces-  
sory or Optional Heater is Installed) — Upon a call for heat-  
ing through terminal W1, IFC and heater contactor no. 1 (HC1)  
are energized. On units equipped for 2 stages of heat, when ad-  
ditional heat is needed, HC2 is energized through W2.  
COOLING UNITS WITH ECONOMI$ER — When the  
OAT is above the ECON SP set point and the room thermostat  
calls for Stage 1 cooling (R to G + Y1), the indoor-fan motors  
(IFM) is energized and the EconoMi$er damper modulates to  
minimum position. The compressor contactor and OFC are  
energized to start the compressor and outdoor-fan motor  
(OFM). After the thermostat is satisfied, the damper modulates  
to the fully closed position when the IFM is deenergized.  
When the OAT is below the ECON SP setting and the room  
thermostat calls for Stage 1 cooling (R to G + Y1), the  
EconoMi$er modulates to the minimum position when the  
IFM is energized. The EconoMi$er provides Stage 1 of cooling  
by modulating the return and outdoor air dampers to maintain a  
55 F supply air set point. If the supply-air temperature (SAT) is  
greater than 57 F, the EconoMi$er modulates open, allowing a  
greater amount of outdoor air to enter the unit. If the SAT drops  
below 53 F, the outdoor air damper modulates closed to reduce  
the amount of outdoor air. When the SAT is between 53 and  
57 F, the EconoMi$er maintains its position.  
If outdoor air alone cannot satisfy the cooling requirements  
of the conditioned space, and the OAT is above the MECH  
CLG LOCKOUT set point, the EconoMi$er integrates free  
cooling with mechanical cooling. This is accomplished by the  
strategies below.  
NOTE: Compressors have a two-minute Minimum On and  
Minimum Off, which are accomplished by the strategies  
below.  
1. If Y1 is energized, and the room thermostat calls for Y2  
(2-stage thermostat), the compressor and OFC are ener-  
gized. The position of the EconoMi$er damper is main-  
tained at its current value.  
2. If Y1 is energized for more than 20 minutes, and Y2 is  
not energized (whether or not a 2-stage thermostat is  
used), the compressor and OFC are energized. The posi-  
tion of the EconoMi$er damper is maintained at its cur-  
rent value.  
3. If Y1 is energized, and compressor no. 1 is already ener-  
gized (see Step 2) and the room thermostat calls for Y2,  
compressor no. 1 continues to operate. If Y2 remains  
energized for more than 20 minutes, compressor no. 2 is  
energized.  
NOTE: Compressor no. 2 cannot be energized unless there is a  
signal for Y2 from the space thermostat.  
4. If compressor no. 2 is energized, and the Y2 signal from  
the thermostat is satisfied, compressors 1 and 2 are deen-  
ergized. Re-asserting Y2 will start compressor no. 1 and  
(after a 20-minute interstage delay) compressor no. 2.  
5. If compressor no. 1 is energized and the thermostat is sat-  
isfied, compressor no. 1, the OFM, and IFM are deener-  
gized and the EconoMi$er modulates closed.  
The 2-phase refrigerant passes through the evaporators and  
is changed into a vapor. The air passing over the evaporator  
coils will become colder than during normal operation as a re-  
sult of the colder refrigerant temperatures. However, as it pass-  
es over the subcooler coils, the air will be warmed, decreasing  
the sensible capacity and reducing the sensible heat of the roof-  
top unit.  
As the refrigerant leaves the evaporator, the refrigerant  
passes a subcooler control low-pressure switch (S-LPS1 for  
circuit 1 or S-LPS2 for circuit 2) in the suction line. This low-  
pressure switch will deactivate the MoistureMiser package  
when the suction pressure reaches 60 psig. The subcooler con-  
trol low-pressure switch is an added safety device to protect  
against evaporator coil freeze-up during low ambient opera-  
tion. The subcooler control low-pressure switch will only  
deactivate the 3-way liquid line solenoid valve in the Mois-  
tureMiser circuit. The compressors will continue to run as long  
as there is a call for cooling, regardless of the position of the  
subcooler control low-pressure switch. The 3-way solenoid  
valve and the MoistureMiser package will be reactivated only  
when the call for cooling has been satisfied, the subcooler con-  
trol low-pressure switch has closed above 80 psig, and a new  
call for cooling exists. The crankcase heaters on the scroll com-  
pressors provide additional protection for the compressors due  
to the additional refrigerant charge in the subcooler.  
When the OAT is below the MECH CLG LOCKOUT set  
point, the compressors remain off.  
23  
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Fig. 30 — MoistureMiser Operation Diagram  
When the humidistat is satisfied, the humidistat internal  
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.  
FILTERS — Clean or replace at start of each heating and cool-  
ing season, or more often if operating conditions require. Refer  
to Table 1 for type and size.  
switch opens, cutting power to and deenergizing the LLSVs.  
The refrigerant is routed back through the evaporators and the  
sub-cooler coils are removed from the refrigerant loops. When  
the thermostat is satisfied, C1 and C2 are deenergized and the  
compressors, IFM, and OFMs shut off. If the thermostat  
fan selector switch is in the ON position, the IFM will run  
continuously.  
NOTE: The 50TJ028 unit requires industrial grade throwaway  
filters capable of withstanding face velocities up to 625 fpm.  
Ensure that replacement filters for the 50TJ028 units are rated  
for 625 fpm.  
SERVICE  
OUTDOOR-AIR INLET SCREENS — Clean screens with  
steam or hot water and a mild detergent. Do not use throwaway  
filters in place of screens.  
Before performing service or maintenance operations on  
unit, turn off main power switch to unit. Turn off accessory  
heater power switch if applicable. Electrical shock could  
cause personal injury.  
Lubrication  
COMPRESSORS — Each compressor is charged with the  
correct amount of oil at the factory. Conventional white oil  
(Sontext 200LT) is used. White oil is compatible with 3GS oil,  
and 3GS oil may be used if the addition of oil is required. See  
compressor nameplate for original oil charge. A complete re-  
charge should be four ounces less than the original oil charge.  
When a compressor is exchanged in the field it is possible that  
a major portion of the oil from the replaced compressor may  
still be in the system. While this will not affect the reliability of  
the replacement compressor, the extra oil will add rotor drag  
and increase power usage. To remove this excess oil, an access  
valve may be added to the lower portion of the suction line at  
Cleaning — Inspect unit interior at beginning of each heat-  
ing and cooling season and as operating conditions require.  
Remove unit top panel and/or side panels for access to unit  
interior.  
EVAPORATOR COIL — Clean as required with a commer-  
cial coil cleaner.  
NOTE: The 50TJ028 unit has a mist eliminator screen attached  
to the evaporator coil to prevent condensate runoff at high wet-  
bulb conditions. Check periodically and clean as necessary.  
24  
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the inlet of the compressor. The compressor should then be run  
for 10 minutes, shut down, and the access valve opened until  
no oil flows. This should be repeated twice to make sure the  
proper oil level has been achieved.  
FAN SHAFT BEARINGS — For size 016 units, bearings are  
permanently lubricated. No field lubrication is required. For  
size 020-028 units, the bearings are of the pillow block type  
and have grease fittings. The bearing opposite the motor end  
has an extended tube line so it can be lubricated from the motor  
side. Lubricate the bearings twice annually.  
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.  
50TJ020-028 UNITS (See Fig. 33) — The 50TJ020-028  
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.  
2. Remove the center post (located between the evaporator  
fan and heating control access panels) and all screws se-  
curing it.  
Typical lubricants are given below:  
MANUFACTURER  
LUBRICANT  
Texaco  
Mobil  
Sunoco  
Texaco  
Regal AFB-2*  
Mobilplex EP No. 1  
Prestige 42  
Multifak 2  
*Preferred lubricant because it contains rust and oxidation inhibitors.  
3. Loosen nuts on the two carriage bolts in the motor mount-  
ing 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.  
CONDENSER AND EVAPORATOR-FAN MOTOR  
BEARINGS — The condenser and evaporator-fan motors  
have permanently-sealed bearings, so no field lubrication is  
necessary.  
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.  
Evaporator Fan Performance Adjustment  
(Fig. 31-33) — Fan motor pulleys are factory set for speed  
shown in Table 1.  
To change fan speeds:  
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.  
1. Shut off unit power supply.  
2. a. Size 016 Only: Loosen belt by loosening fan motor  
mounting plate nuts.  
10. Disconnect wiring connections and remove the 4 mount-  
ing bolts.  
11. Remove the motor.  
b. Size 020-028 Only: Loosen nuts on the 2 carriage  
bolts in the motor mounting base. Install jacking  
bolt and plate under motor base (bolt and plate are  
shipped in installer’s packet). See Fig. 33. Using  
bolt and plate, raise motor to top of slide and  
remove belt. Secure motor in this position by tight-  
ening the nuts on the carriage bolts.  
12. To install the new motor, reverse Steps 1-11.  
3. Loosen movable-pulley flange setscrew (see Fig. 31).  
4. Screw movable flange toward fixed flange to increase  
speed and away from fixed flange to decrease speed. In-  
creasing fan speed increases load on motor. Do not ex-  
ceed maximum speed specified in Table 1.  
See Table 7 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 26.  
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.  
Evaporator Fan Service and Replacement  
50TJ016 UNITS (See Fig. 32)  
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 as-  
sembly 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.  
Fig. 31 — Evaporator-Fan Pulley Alignment  
and Adjustment  
25  
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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.  
NOTE: A 31/2-in. bolt and threaded plate are included in the  
installers packet. They should be added to the motor support chan-  
nel below the motor mounting plate to aid in raising the motor. The  
plate part number is 50DP503842. The adjustment bolt is 3/8-16 x  
13/4 in.-LG.  
Fig. 32 — 50TJ016 Evaporator-Fan  
Motor Section  
Fig. 33 — 50TJ020-028 Evaporator-Fan  
Motor Section  
Belt Tension Adjustment — To adjust belt tension:  
1. Loosen fan motor bolts.  
2. Adjust belt tension:  
a. Size 016 Units: Move motor mounting plate up or  
down for proper belt tension (1/2 in. deflection with  
one finger).  
b. Size 020-028 Units: Turn motor jacking bolt to move  
motor mounting plate up or down for proper belt ten-  
sion (3/8 in. deflection at midspan with one finger [9  
lb force]).  
NOTE: Dimensions are in inches).  
3. Tighten nuts.  
Fig. 34 — Condenser-Fan Adjustment,  
50TJ016,020  
4. Adjust bolts and nut on mounting plate to secure motor in  
fixed position.  
Condenser-Fan Adjustment  
50TJ016,020 UNITS (Fig. 34)  
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.  
50TJ024,028 UNITS (Fig. 35)  
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.  
NOTE: Dimensions are in inches.  
Fig. 35 — Condenser-Fan Adjustment,  
50TJ024,028  
26  
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sensor fault must be corrected to enable EconoMi$er to revert  
to normal operation.  
If the CONFIG button is pressed and held for more than  
30 seconds and released, the EconoMi$er controller will enable  
the enthalpy comparison strategy (with outdoor air enthalpy  
and return air enthalpy sensors installed).  
EconoMi$er Adjustment  
LED INDICATION — The EconoMi$er controller features  
an onboard diagnostic LED (light-emitting diode) that flashes  
to indicate its status. See Table 15 for flash codes. The control-  
ler also has terminal connections (REM LED) for remotely  
mounting an LED, if desired. The flash code priorities are as  
follows:  
1. On/Off or continuous flash  
2. Critical fault  
3. Non-critical fault  
Power Failure — Dampers have a spring return. In event  
of power failure, dampers will return to fully closed position  
until power is restored. Do not manually operate damper  
motor.  
If any sensors are opened, shorted, or removed, the  
EconoMi$er determines whether the failure is critical or non-  
critical and flashes the appropriate code. If a non-critical sensor  
fault occurs (i.e., outdoor air humidity), the EconoMi$er auto-  
matically reconfigures its control strategy to a more appropriate  
mode. If a critical sensor fault occurs (i.e., supply air sensor),  
the EconoMi$er reverts to a safe mode of operation until the  
sensor problem is resolved.  
MANUAL CONFIGURATION PUSHBUTTON — The  
EconoMi$er controller also features an onboard button (CON-  
FIG) to help troubleshoot the system. See Fig. 16. The button  
can perform 3 different functions.  
Pressing the CONFIG button for more than three seconds,  
but less than ten seconds and then releasing will start the auto-  
matic test procedure. The damper will modulate fully open,  
wait, and modulate closed. This process takes three minutes to  
complete. Use this feature to determine if the actuator can be  
commanded.  
If the CONFIG button is pressed and held for ten seconds  
and less than 30 seconds then released, the EconoMi$er con-  
troller reconfigures its mode of operation based on the sensors  
that are connected and functioning normally, and cancels the  
automatic test procedure.  
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.  
NOTE: Do not use recycled refrigerant as it may contain con-  
taminants.  
NO CHARGE — Use standard evacuating techniques. After  
evacuating system, weigh in the specified amount of refriger-  
ant (refer to Table 1).  
LOW CHARGE COOLING — Using cooling charging chart  
(see Fig. 36), add or remove refrigerant until conditions of the  
chart are met. Note that charging chart is different from those  
normally used. An accurate pressure gage and temperature-  
sensing device is required. Charging is accomplished by ensur-  
ing the proper amount of liquid subcooling. Measure liquid line  
pressure at the liquid line service valve using pressure gage.  
Connect temperature sensing device to the liquid line near the  
liquid line service valve and insulate it so that outdoor ambient  
temperature does not affect reading.  
TO USE THE COOLING CHARGING CHART — Use the  
above temperature and pressure readings, and find the intersec-  
tion point on the cooling charging chart. If intersection point on  
chart is above line, add refrigerant. If intersection point on  
chart is below line, carefully recover some of the charge. Re-  
check suction pressure as charge is adjusted. NOTE: Indoor-air  
CFM must be within normal operating range of unit. All out-  
door fans must be operating.  
If the EconoMi$er controller recognized a non-critical  
sensor fault, and flashed a code (i.e., FLASH 6, outdoor air  
humidity sensor fault) the FLASH CODE will be cleared, and  
normal operation begins. Ensure faulty sensor is removed  
before clearing faults.  
If the EconoMi$er controller recognizes a critical sensor  
fault, and flashes a code (i.e., FLASH 4, discharge air thermo-  
stat fault) the FLASH code will not be cleared, and the  
EconoMi$er will remain in the safe operation mode. The  
The TXV (thermostatic expansion valve) is set to maintain  
between 15 and 20 degrees of superheat at the compressors.  
The valves are factory set and should not require re-adjustment.  
Table 15 — EconoMi$er Control Module Flash Code Identification  
FLASH CODE  
Constant On  
Constant Off  
CAUSE  
Normal operation  
No power  
ACTION TAKEN BY ECONOMI$ER  
Normal operation.  
No operation.  
Continuous  
Flash  
CONFIG button pushed and held  
between 3 and 9 seconds  
Outdoor air damper is stroked fully open, then closed  
(automatic test procedure takes 3 minutes to complete).  
Flash One  
Flash Two  
Flash Three  
Control board fault  
Thermostat fault (i.e., Y2 without Y1)  
Actuator fault  
System shutdown.  
System shutdown until corrected.  
Revert to mechanical cooling only.  
Continue operation with damper at minimum position.  
Revert to mechanical cooling only.  
Flash Four  
Discharge air thermistor fault  
Continue operation with damper at minimum position.  
Disable mechanical cooling lockout.  
Continue operation with dry bulb or dry bulb differential switchover.  
Flash Five  
Flash Six  
Outdoor air temperature sensor fault  
Outdoor air humidity sensor fault  
Continue operation with single enthalpy EconoMi$er  
switchover or dry bulb EconoMi$er switchover (without  
humidity sensor).  
Flash Seven  
Return air temperature sensor fault  
Continue operation with single enthalpy, differential dry  
bulb, or dry bulb EconoMi$er switchover.  
Flash Eight  
Return air humidity sensor fault  
Flash Nine  
Flash Ten  
Carbon Dioxide (CO2) sensor fault  
Continue operation without ventilation control.  
Onboard adjustment potentiometer fault  
Continue operation with default potentiometer settings.  
27  
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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 CLO (compressor lockout) will lock the compressors off.  
To reset, manually move the thermostat setting.  
EVAPORATOR FAN MOTOR PROTECTION — A manu-  
al 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.  
BOTH CIRCUITS  
ALL OUTDOOR FANS MUST BE OPERATING  
140  
120  
ADD CHARGE IF ABOVE CURVE  
100  
80  
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 acti-  
vates, that refrigerant circuit will be automatically locked out  
by the CLO. To reset, manually move the thermostat setting.  
REDUCE CHARGE IF BELOW CURVE  
60  
FREEZE PROTECTION THERMOSTAT (FPT) — An FPT  
is located on the top and bottom of the evaporator coil. It de-  
tects frost build-up and turns off the compressor, allowing the  
coil to clear. Once the frost has melted, the compressor can be  
reenergized.  
40  
50  
100  
150  
200  
250  
300  
350  
400  
LIQUID PRESSURE AT LIQUID VALVE (PSIG)  
Fig. 36 Cooling Charging Chart  
Relief Devices — All units have relief devices to protect  
against damage from excessive pressures (e.g., fire). These de-  
vices protect the high and low side.  
MOISTUREMISER SYSTEM CHARGING — The system  
charge for units with the MoistureMiser option is greater than  
that of the standard unit alone. The charge for units with this  
option is indicated on the unit nameplate drawing. To charge  
systems using the MoistureMiser Dehumidification package,  
fully evacuate, recover, and re-charge the system to the name-  
plate specified charge level. To check or adjust refrigerant  
charge on systems using the MoistureMiser Dehumidification  
package, charge per the standard subcooling charts. The sub-  
cooler MUST be deenergized to use the charging charts. The  
charts reference a liquid pressure (psig) and temperature at a  
point between the condenser coil and the subcooler coil. A tap  
is provided on the unit to measure liquid pressure entering the  
subcooler (leaving the condenser).  
Control Circuit, 24-V — This control circuit is protect-  
ed 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.  
EconoMi$er LEDs — The EconoMi$er control module  
has an LED for diagnostic purposes. The flash code identifica-  
tion is shown in Table 15.  
Filter Drier — Replace whenever refrigerant system is ex-  
Optional Hinged Access Doors — When the optional  
service package is ordered or the if the hinged access doors  
option is ordered, the unit will be provided with external and  
internal hinged access doors to facilitate service.  
posed to atmosphere.  
Protective Devices  
COMPRESSOR PROTECTION  
Four external hinged access doors are provided. All external  
Overcurrent — Each compressor has internal line break motor  
protection, except the circuit no. 1 on the 50TJ028 unit. Com-  
pressor no. 1 on the 50TJ028 unit uses an electronic module lo-  
cated with the compressor junction box, to provide motor pro-  
tection. This electronic module monitors winding and dis-  
charge temperatures. If these temperatures reach the trip  
values, the module interrupts the control line and causes the  
compressor to switch off.  
1
doors are provided with 2 large /4 turn latches with folding  
bail-type handles. (Compressor access doors have one latch.) A  
single door is provided for filter and drive access. One door is  
provided for control box access. The control box access door is  
interlocked with the non-fused disconnect which must be in the  
OFF position to open the door. Two doors are provided for ac-  
cess to the compressor compartment.  
Two internal access doors are provided inside the filter/  
drive access door. The filter access door (on the left) is secured  
by 2 small 1/4 turn latches with folding bail-type handles. This  
door must be opened prior to opening the drive access door.  
The drive access door is shipped with 2 sheet metal screws  
holding the door closed. Upon initial opening of the door, these  
screws may be removed and discarded. The door is then held  
shut by the filter access door, which closes over it.  
Crankcase Heater — Only the 50TJ028 unit and units with  
the optional MoistureMiser Dehumidification system are  
equipped with a 70-watt crankcase heater to prevent absorption  
of liquid refrigerant by oil in the crankcase when the compres-  
sor is idle. The crankcase heater is energized whenever there is  
a main power to the unit and the compressor is not energized.  
IMPORTANT: After prolonged shutdown or servicing,  
energize the crankcase heaters for 24 hours before start-  
ing the compressors.  
28  
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ELECTRIC HEAT  
208/240 v Amps 200/230 v kW  
A
B
C
71.3/82.3  
117/135  
156/180  
25.7/34.2  
42.2/56.1  
56.2/74.8  
Fig. 37 Typical Wiring Schematic (50TJ024, 208/230-3-60 Shown)  
29  
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Fig. 37 Typical Wiring Schematic (50TJ024, 208/230-3-60 Shown) (cont)  
Fig. 38 Typical Component Arrangement (50TJ024 Shown)  
30  
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LEGEND AND NOTES FOR FIG. 37 AND 38  
LEGEND  
GND Ground  
TB  
TC  
TH  
Ter minal Block  
AHA  
Adjustable Heat Anticipator  
HC Heater Contactor  
HPS High-Pressure Switch  
HTR Heater  
Thermostat Cooling  
Thermostat Heating  
BRK W/ATBreaks with Amp Turns  
C
Contactor, Compressor  
Circuit Breaker  
TRAN Transformer  
CB  
IFC Indoor-Fan Contactor  
IFCB Indoor-Fan Circuit Breaker  
IFM Indoor-Fan Motor  
IFR Indoor-Fan Relay  
CC  
Cooling Compensator  
Crankcase Heater  
Compressor Lockout  
Compressor Motor  
Control Relay  
Terminal (Marked)  
CH  
CLO  
COMP  
CR  
Terminal (Unmarked)  
Ter minal Block  
Splice  
L
Light  
LOR Lockout Relay  
DAT  
DM  
Discharge Air Thermistor  
Damper Motor  
LPS Low-Pressure Switch  
LS  
Limit Switch  
DU  
Dummy Terminal  
Enthalpy Control  
Equipment  
NEC National Electrical Code  
OAT Outdoor-Air Thermostat  
OFC Outdoor-Fan Contactor  
OFM Outdoor-Fan Motor  
EC  
Factory Wiring  
EQUIP  
FL  
Field Control Wiring  
Option/Accessory Wiring  
Fuse Link  
FLA  
FPT  
FU  
Full Load Amps  
Freeze Protection Thermostat  
Fuse  
OP Overcurrent Protection  
To indicate common potential  
only; not to represent wiring.  
PL  
Plug Assembly  
PRI Primary  
NOTES:  
1. Compressor and fan motor(s) 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. TRAN1 is wired for 230 v (60 Hz) or 220 v (50 Hz) operation. If unit is 208 v, dis-  
connect the black wires from the ORN TRAN wire and reconnect to the RED  
TRAN wire, apply wirenuts to wires.  
5. IFCB must trip amps is equal to or less than 140% FLA.  
6. The CLO locks out the compressor to prevent short cycling on compressor over-  
load and safety devices. Before replacing CLO, check these devices.  
7. Jumpers are omitted when unit is equipped with EconoMi$er.  
8. Number(s) indicates the line location of used contacts. A bracket over (2) num-  
bers signifies a single-pole, double-throw contact. An underlined number sig-  
nifies a normally closed contact. Plain (no line) number signifies a normally open  
contact.  
31  
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TROUBLESHOOTING  
Refer to Tables 16-18 for troubleshooting details.  
Table 16 Cooling Service Analysis  
PROBLEM  
CAUSE  
REMEDY  
Compressor and  
condenser fan  
will not start.  
Power failure.  
Fuse blown or circuit breaker tripped.  
Defective thermostat, contactor, transformer, or control  
relay.  
Call power company.  
Replace fuse or reset circuit breaker.  
Replace component.  
Insufficient line voltage.  
Incorrect or faulty wiring.  
Thermostat setting too high.  
Determine cause and correct.  
Check wiring diagram and rewire correctly.  
Lower thermostat setting below room temperature.  
Compressor will not start Faulty wiring or loose connections in compressor circuit. Check wiring and repair or replace.  
but condenser fan runs.  
Compressor motor burned out, seized, or internal over- Determine cause. Replace compressor.  
load open.  
Defective overload.  
Determine cause and replace.  
Compressor locked out  
One leg of 3-phase power dead.  
Determine cause for safety trip and reset lockout.  
Replace fuse or reset circuit breaker.  
Determine cause.  
Compressor cycles  
(other than normally  
satisfying thermostat).  
Refrigerant overcharge or undercharge.  
Recover refrigerant, evacuate system, and recharge  
to nameplate.  
Defective compressor.  
Insufficient line voltage.  
Blocked condenser.  
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.  
Recover refrigerant, evacuate system, and recharge.  
Clean coil or remove restriction.  
Replace filter.  
Defective overload.  
Defective thermostat.  
Faulty condenser-fan motor.  
Restriction in refrigerant system.  
Dirty air filter.  
Unit undersized for load.  
Thermostat set too low.  
Low refrigerant charge.  
Air in system.  
Compressor operates  
continuously.  
Condenser coil dirty or restricted.  
Excessive head pressure. Dirty air filter.  
Dirty condenser coil.  
Clean coil.  
Refrigerant overcharged.  
Faulty TXV.  
Recover excess refrigerant.  
1. Check TXV bulb mounting and secure tightly to  
suction line.  
2. Replace TXV if stuck open or closed.  
Air in system.  
Recover refrigerant, evacuate system, and recharge.  
Determine cause and correct.  
Check for leaks, repair, and recharge.  
Remove restriction.  
Condenser air restricted or air short-cycling.  
Low refrigerant charge.  
Restriction in liquid tube.  
High heat load.  
Head pressure too low.  
Excessive suction  
pressure.  
Check for source and eliminate.  
Faulty TXV.  
1. Check TXV bulb mounting and secure tightly to  
suction line.  
2. Replace TXV if stuck open or closed.  
Refrigerant overcharged.  
Suction pressure too low. Dirty air filter.  
Low refrigerant charge.  
Recover excess refrigerant.  
Replace filter.  
Check for leaks, repair, and recharge.  
Remove source of restriction.  
1. Check TXV bulb mounting and secure tightly to  
suction line.  
2. Replace TXV if stuck open or closed.  
Metering device or low side restricted.  
Faulty TXV.  
Insufficient evaporator airflow.  
Increase air quantity. Check filter and replace if  
necessary.  
Temperature too low in conditioned area.  
Field-installed filter drier restricted.  
Reset thermostat.  
Replace.  
LEGEND  
TXV Thermostatic Expansion Valve  
32  
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Table 17 EconoMi$er Troubleshooting  
PROBLEM  
POTENTIAL CAUSE  
REMEDY  
Damper Does Not  
Open  
Indoor (Evaporator) Fan is  
Off  
Check to ensure that 24 vac is present at Terminal C1 (Common Power)  
on the IFC (Indoor [Evaporator] Fan Contactor) or that 24 vac is present at  
the IFO (Indoor [Evaporator] Fan On) terminal. Check whether 24 vac is  
present at PL6-1 (red wire) and/or PL6-3 (black wire). If 24 vac is  
not present, check wiring (see unit label diagram).  
Check proper thermostat connection to G on the connection board.  
No Power to EconoMi$er  
Controller  
Check to ensure that 24 vac is present across Terminals 24 VAC and  
24 V COM on the EconoMi$er control. If 24 vac is not present, check wiring  
(see unit label diagram). If 24 vac is present, STATUS light should be on  
constantly.  
No Power to G Terminal  
Controller Fault  
If IFM is on, check to ensure 24 vac is present on G Terminal of the  
EconoMi$er controller. If 24 vac is not present, check wiring (see unit  
label diagram).  
If STATUS light is flashing one flash, the EconoMi$er controller is  
experiencing a fault condition. Cycle power to the controller. If condition  
continues, replace the EconoMi$er controller.  
Thermostat Fault  
If STATUS light is flashing two flashes, the EconoMi$er controller senses that  
the thermostat is wired incorrectly. Check wiring between the thermostat  
and the connection board in the electrical panel. The fault condition is  
caused by Y2 being energized before Y1.  
Actuator Fault  
Check the wiring between the EconoMi$er controller and the actuator.  
Hold CONFIG button between 3 and 10 seconds to verify the  
actuators operation. (This process takes 3 minutes to complete.)  
EconoMi$er  
Operation Limited to  
Minimum Position  
Minimum Position Set  
Incorrectly  
EconoMi$er Changeover  
Set Point Set Too High or  
Too Low  
Verify that the MIN POS (%) is set greater than zero. Adjust MIN POS (%)  
to 100% to verify operation, and then set to correct setting.  
Set at correct value. See Table 5.  
Discharge Air  
Thermistor Faulty  
If STATUS light is flashing 4 flashes, Discharge Air Thermistor is  
faulty. Check wiring or replace sensor.  
Outdoor Air Temperature  
Sensor Faulty  
If STATUS light is flashing 5 flashes, Outdoor Air Temperature Sensor is  
faulty. Check wiring or replace sensor.  
Damper Position  
Less than Minimum  
Position Set Point  
Supply Air Low Limit  
Strategy Controlling  
The supply-air temperature is less than 45 F, causing the minimum  
position to be decreased. Refer to the Start-Up instructions. Verify correct  
setting of MIN POS (%). If correct, EconoMi$er is operating correctly.  
Damper Does Not  
Return to Minimum  
Position  
CO2 Ventilation Strategy  
Controlling  
If a CO2 sensor is being used, and the damper position is greater than  
minimum position, the ventilation control strategy is controlling. Refer to  
The Start-Up instructions. EconoMi$er is operating correctly.  
Damper Does Not  
Close on Power Loss  
Damper Travel is  
Restricted  
Check to ensure the damper is not blocked.  
LEGEND  
IFM  
PL  
Indoor Fan Motor  
Plug  
Table 18 MoistureMiser Dehumidification Subcooler Service Analysis  
PROBLEM  
CAUSE  
REMEDY  
Subcooler will not energize  
No power to subcooler  
control transformer.  
Check power source. Ensure all wire connections  
are tight.  
No power from subcooler  
control transformer to liquid line three way valve.  
1. Fuse open; check fuse. Ensure continuity of wiring.  
2. Subcooler control low pressure switch open.  
Cycle unit off and allow low-pressure switch  
to reset. Replace switch if it will not close.  
3. Transformer bad; check transformer.  
Liquid line three-way valve  
will not operate.  
1. Solenoid coil defective; replace.  
2. Solenoid valve stuck closed; replace.  
Subcooler will not deenergize  
Low system capacity  
Liquid Line three-way valve  
will not close.  
Low refrigerant charge or  
frosted coil.  
Valve is stuck open; replace.  
1. Check charge amount. See system charging  
section.  
2. Evaporator coil frosted; check and replace  
subcooler control low pressure switch if necessary.  
33  
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SERVICE TRAINING  
Packaged Service Training programs are an excellent way to increase your knowledge of the equipment  
discussed in this manual, including:  
• Unit Familiarization  
• Installation Overview  
• Maintenance  
• Operating Sequence  
A large selection of product, theory, and skills programs are available, using popular video-based formats  
and materials. All include video and/or slides, plus companion book.  
Classroom Service Training which includes “hands-on” experience with the products in our labs can  
mean increased confidence that really pays dividends in faster troubleshooting and fewer callbacks. Course  
descriptions and schedules are in our catalog.  
CALL FOR FREE CATALOG 1-800-962-9212  
[
] Packaged Service Training  
[
] Classroom Service Training  
Copyright 2001 Carrier Corporation  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
PC 111 Catalog No. 535-034 Printed in U.S.A. Form 50TJ-17SI Pg 34 2-01 Replaces: 50TJ-14SI  
Book 1  
Tab 1b  
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START-UP CHECKLIST  
MODEL NO.:  
DATE:  
SERIAL NO.:  
TECHNICIAN:  
PRE-START-UP:  
VERIFY THAT ALL PACKING MATERIALS HAVE BEEN REMOVED FROM UNIT  
VERIFY INSTALLATION OF INDOOR FAN MOTOR ADJUSTMENT BOLT (016 UNITS) OR ADJUSTMENT  
BOLT AND PLATE (020-028 UNITS)  
VERIFY INSTALLATION OF ECONOMI$ER HOOD  
VERIFY THAT CONDENSATE CONNECTION IS INSTALLED PER INSTRUCTIONS  
VERIFY THAT ALL ELECTRICAL CONNECTIONS AND TERMINALS ARE TIGHT  
CHECK THAT FILTERS AND SCREENS ARE CLEAN AND IN PLACE  
VERIFY THAT UNIT IS LEVEL  
CHECK FAN WHEEL AND PROPELLER FOR LOCATION IN HOUSING/ORIFICE, AND VERIFY SETSCREW  
IS TIGHT  
VERIFY THAT FAN SHEAVES ARE ALIGNED AND BELTS ARE PROPERLY TENSIONED  
VERIFY THAT SCROLL COMPRESSOR IS ROTATING IN THE CORRECT DIRECTION  
VERIFY THAT CRANKCASE HEATER HAS BEEN ENERGIZED FOR 24 HOURS (SIZE 028 AND UNITS WITH  
OPTIONAL MOISTUREMISER DEHUMIDIFICATION SYSTEM ONLY)  
START-UP:  
ELECTRICAL  
SUPPLY VOLTAGE  
L1-L2  
L2-L3  
L2  
L3-L1  
L3  
COMPRESSOR AMPS — COMPRESSOR NO. 1 L1  
— COMPRESSOR NO. 2  
L1  
L2  
L3  
SUPPLY FAN AMPS  
EXHAUST FAN AMPS  
L1  
ELECTRIC HEAT AMPS (IF SO EQUIPPED)  
L2  
L31  
TEMPERATURES  
OUTDOOR-AIR TEMPERATURE  
RETURN-AIR TEMPERATURE  
COOLING SUPPLY AIR  
F DB (Dry-Bulb)  
F DB  
F
F WB (Wet-Bulb)  
ELECTRIC HEAT SUPPLY AIR (IF SO EQUIPPED)  
F
PRESSURES  
REFRIGERANT SUCTION  
REFRIGERANT DISCHARGE CIRCUIT NO. 1  
CIRCUIT NO. 1  
PSIG  
PSIG  
CIRCUIT NO. 2  
CIRCUIT NO. 2  
PSIG  
PSIG  
VERIFY REFRIGERANT CHARGE USING CHARGING CHART ON PAGE 28.  
GENERAL  
ECONOMI$ER MINIMUM VENT AND CHANGEOVER SETTINGS TO JOB REQUIREMENTS  
VERIFY INSTALLATION OF ALL OPTIONS AND ACCESSORIES  
Copyright 2001 Carrier Corporation  
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.  
Book  
1
PC 111  
Catalog No. 535-034  
Printed in U.S.A.  
Form 50TJ-17SI  
Pg CL-1  
2-01  
Replaces: 50TJ-14SI  
Tab  
1b  
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