Troubleshooting; Unit Will Not Start Or Starts Then Stops; Unit Operates Long Or Continuously In Cooling - Carrier 69NT40-541-001 Operation And Service

Container refrigeration units

Table of Contents

CONDITION

6.1

UNIT WILL NOT START OR STARTS THEN STOPS

External power source OFF

Start-Stop switch OFF or defective

No power to unit

Circuit breaker tripped or OFF

Autotransformer not connected

Circuit breaker OFF or defective

Control transformer defective

Loss of control power

Fuses (F3A, F3B) blown

Start-Stop switch OFF or defective

Evaporator fan motor internal protector open

Condenser fan motor internal protector open

Component(s) Not Op-

Compressor internal protector open

erating

High pressure switch open

Heat termination thermostat open

Low line voltage

Single phasing

Compressor hums, but

does not start

Shorted or grounded motor windings

Compressor seized

6.2

UNIT OPERATES LONG OR CONTINUOUSLY IN COOLING

Hot load (Failure to Pre-cool)

Container

Defective box insulation or air leak

Shortage of refrigerant

Evaporator coil covered with ice

Evaporator coil plugged with debris

Evaporator fan(s) rotating backwards

Defective evaporator fan motor/capacitor

Air bypass around evaporator coil

Refrigeration System

Controller set too low

Compressor service valves or liquid line shutoff valve partially closed

Dirty condenser

Compressor worn

Current limit (function code Cd32) set to wrong value

Suction modulation valve malfunction

SECTION 6