Electrical Maintenance
50
Auto Phase System
The Auto Phase system automatically adjusts the
phase sequence of the power supply to correspond
with the wiring of the electric motor. The main
components of the system are the phase selection
module (PSM), its two relays, and the two motor
contactors (MC1 and MC2). Contactor MC1 is
wired to retain the phase sequence. Contactor
MC2 is wired to change the phase sequence. The
PSM senses the phase sequence at the heater
contactor and energizes the appropriate motor
contactor by energizing one of the relays.
Troubleshooting the Auto Phase System
If the Electric Motor Runs Backwards (Unit Airflow
Incorrect):
1. Turn the electric power supply Off and check
the unit wiring. Refer to the appropriate
wiring diagrams, schematics, and to Figure 22
on page 51.
a. The three wires from the PSM should be
connected to the heater contactor terminals
as follows: Brown wire to terminal L1,
Blue wire to terminal L2, and Black wire
to terminal L3.
b. Wires L1, L2, and L3 should be connected
respectively to terminals L1, L2, and L3
on the heater contactor and both motor
contactors.
c. Wires T1A, T2A, and T3A should be
connected respectively to terminals T1,
T2, and T3 on MC1.
d. Wires T1A, T2A, and T3A should be
connected respectively to terminals T3,
T2, and T1 on MC2.
e. Wires T1A, T2A, and T3A should be
connected respectively to terminals L1,
L2, and L3 on the overload relay.
f.
Wires 1, 2, and 3 should be connected
respectively to terminals T1, T2, and T3
on the overload relay.
g. Wires Brown, Blue, and Black should be
connected respectively to terminals X, Y,
and Z in the power receptacle.
h. Wires Brown, Blue, and Black should be
connected respectively to terminals L1,
L2, and L3 on MC1.
i.
Wires 7EC, 7EB, and CH should be
connected to the corresponding terminals
on the PSM. The 7EH wires should be
connected to the 7EA and 8 terminals on
the PSM.
j.
The electric motor must be wired
correctly.
2. Check the relays on the PSM to make sure that
one of them is not faulty (contacts stuck
closed).
3. Check MC1 and MC2 to make sure that one of
them is not faulty (contacts stuck closed).
1.
Condenser Air Out
3.
Evaporator Air Out
2.
Condenser Air In
4.
Evaporator Air In
Figure 21: Host Unit Air Flow
1
3
4
2
AJA920
ARA104
Summary of Contents for 002008
Page 4: ...4 ...
Page 30: ...Unit Description 30 Figure 9 Front View AJA920 ...
Page 31: ...Unit Description 31 1 Access Panels 2 Defrost Damper Figure 10 Back View 1 2 ARA104 ...
Page 114: ...Mechanical Diagnosis 114 ...
Page 116: ...Electric Standby Diagnosis 116 ...
Page 120: ...Remote Evaporator Specifications 120 ...
Page 122: ...Remote Evaporator Maintenance Inspection Schedule 122 ...
Page 128: ...Remote Evaporator Electrical Maintenance 128 ...
Page 132: ...Remote Evaporator Refrigeration Service Operations 132 ...
Page 134: ...Remote Evaporator Structural Maintenance 134 ...
Page 136: ...Remote Evaporator System Diagnosis 136 ...
Page 140: ...Index 140 ...
Page 142: ......
Page 143: ...143 Model 30 Schematic Diagram Page 1 of 2 ...
Page 144: ...144 Model 30 Schematic Diagram Page 2 of 2 ...
Page 145: ...145 Model 30 Wiring Diagram Page 1 of 4 ...
Page 146: ...146 Model 30 Wiring Diagram Page 2 of 4 ...
Page 147: ...147 Model 30 Wiring Diagram Page 3 of 4 ...
Page 148: ...148 Model 30 Wiring Diagram Page 4 of 4 ...
Page 149: ...149 Model 50 Schematic Diagram Page 1 of 2 ...
Page 150: ...150 Model 50 Schematic Diagram Page 2 of 2 ...
Page 151: ...151 Model 50 Wiring Diagram Page 1 of 5 ...
Page 152: ...152 Model 50 Wiring Diagram Page 2 of 5 ...
Page 153: ...153 Model 50 Wiring Diagram Page 3 of 5 ...