Carrier PrimeLINE 69NT40-561-200, Operation And Service Manual

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6–3 T-362
6.3 Unit Runs but has Insufficient Cooling
Refrigeration system
Abnormal pressures Section 6.7
Abnormal temperatures
Section 6.16
Abnormal currents Section 6.17
Controller malfunction
Section 6.9
Evaporator fan or motor defective Section 7.17
Compressor service valves or liquid line shutoff valve
partially closed
Open valves completely
Frost on coil Section 6.10
Digital unloader valve stuck open Replace
Electronic expansion valve Replace
6.4 Unit will not Heat or has Insufficient Heating
No operation of any kind
Start-Stop switch (ST) 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 Section 7.17
Heat relay defective Check
Heater termination thermostat open Section 7.15
Unit will not heat or has
insufficient heat
Heater(s) defective
Section 7.16
Heater contactor or coil defective Replace
Evaporator fan motor(s) defective or rotating
backwards
Section 7.17
Evaporator fan motor contactor defective Replace
Controller malfunction
Section 6.9
Defective wiring Replace
Loose terminal connections Tighten
Low line voltage Section 3.3
6.5 Unit will not Terminate Heating
Unit fails to stop heating
Controller improperly set Reset
Controller malfunction Section 6.9
Heater termination thermostat remains closed along
with the heat relay
Section 7.15
6.6 Unit will not Defrost Properly
Will not initiate defrost
automatically
Defrost timer malfunction (Cd27) Table 4–4
Loose terminal connections Tighten
Defective wiring Replace
Defrost temperature sensor defective or heat
termination thermostat open
Replace
Heater contactor or coil defective Replace
Condition Possible Cause Remedy / Reference