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5-2
T-317
CONDITION
POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.3 UNIT RUNS BUT HAS INSUFFICIENT COOLING
Compressor
Compressor valves defective
6.8
Refrigeration System
Abnormal pressures
5.7
Controller malfunction
5.9
Evaporator fan or motor defective
6.16
Suction modulation valve malfunction
6.18
Condenser Pressure Transducer defective
Check
Shortage of refrigerant
6.7.1
5.4 UNIT WILL NOT HEAT OR HAS INSUFFICIENT HEATING
No operation of any kind
Start-Stop switch OFF or defective
Check
Circuit breaker OFF or defective
Check
External power source OFF
Turn ON
No control power
Circuit breaker or fuse defective
Replace
Control Transformer defective
Replace
Evaporator fan internal motor protector open
6.16
Heat relay defective
Check
Heater termination switch open
6.15
Unit will not heat or has insuffi-
cient heat
Heater(s) defective
6.15
Heater contactor or coil defective
Replace
Evaporator fan motor(s) defective or rotating backwards
6.15/6.16
Evaporator fan motor contactor defective
Replace
Controller malfunction
5.9
Defective wiring
Replace
Loose terminal connections
Tighten
Low line voltage
2.3
5.5 UNIT WILL NOT TERMINATE HEATING
Unit fails to stop heating
Controller improperly set
Reset
Controller malfunction
5.9
Heater termination thermostat remains closed along with
the heat relay
6.15
5.6 UNIT WILL NOT DEFROST PROPERLY
Will not initiate defrost
automatically
Defrost timer malfunction (Cd27)
Table 3-5
Loose terminal connections
Tighten/
Defective wiring
Replace
Defrost temperature sensor defective or heat termination
thermostat open
Replace
Heater contactor or coil defective
Replace
Will not initiate defrost
manually
Manual defrost switch defective
Replace
Defrost temperature sensor open
4.10.4
Initiates but relay (DR) drops
out
Low line voltage
2.3
Initiates but does not defrost
Heater contactor or coil defective
Replace
Heater(s) burned out
6.15