Carrier NDK33BN0KB, Operation & Service Manual

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62-61753-21 10-6
INDICATION/
TROUBLE
POSSIBLE CAUSES
REFERENCE
SECTION
10.4 REFRIGERATION
10.4.1 Unit Will Not Cool
Compressor malfunction Compressor contactor defective Check
Compressor defective
8.6.1
Refrigeration system A defrost cycle did not terminate 9.4.6
Abnormal pressure 9.4.7
10.4.2 Unit Runs But Has Insufficient Cooling
Compressor Compressor defective 8.6.1
Refrigeration system Abnormal pressure 9.4.7
Unloader valve malfunction 8.6.9
Expansion valve malfunction 9.4.11
No or restricted evaporator airflow 9.4.10
Suction Modulation Valve malfunction 8.6.7
Economizer system malfunction 9.4.13
10.4.3 Unit Operates Long Or Continuously In Cooling
Trailer Hot Load Allow time to
pull down
Defective box insulation or air leak Correct
Refrigeration system Abnormal pressure 9.4.7
Temperature controller malfunction 9.4.9
Compressor Defective 8.6.1
10.4.4 Unit Will Not Heat Or Has Insufficient Heating
Unit will not heat or has insuffi-
cient heat Evaporator fan internal motor protector open 8.7.2
Heat relay defective Check
Heater(s) defective 8.7.1
Heater contactor or coil defective Replace
Evaporator fan motor(s) defective or rotating backwards 8.7.2
Evaporator fan motor contactor defective Replace
Controller malfunction 9.4.9
Defective wiring Replace
Loose terminal connections Tighten
Low voltage 9.3
10.4.5 Unit Will Not Terminate Heating
Unit fails to stop heating Controller improperly set Reset
Controller malfunction 9.4.9
Heater termination thermostat remains closed along with
the heat relay Repair