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5--1
T-334
SECTION 5
TROUBLESHOOTING
CONDITION
POSSIBLE CAUSE
REMEDY/
REFERENCE
SECTION
5.1 UNIT WILL NOT START OR STARTS THEN STOPS
No power to unit
External power source OFF
Turn on
Start-Stop switch OFF or defective
Check
Circuit breaker tripped or OFF
Check
Autotransformer not connected
4.2.2
Loss of control power
Circuit breaker OFF or defective
Check
Control transformer defective
Replace
Fuse (F3A/F3B) blown
Check
Start-Stop switch OFF or defective
Check
Component(s) not operating
Evaporator fan motor internal protector open
6.15
Condenser fan motor internal protector open
6.9
Compressor internal protector open
6.5
High pressure switch open
5.7
Heat termination thermostat open
Replace
Loss of communication with expansion module
Check Wiring
Malfunction of current sensor
Replace
Compressor hums, but does not
start
Low line voltage
Check
Single phasing
Check
Shorted or grounded motor windings
6.5
Compressor seized
6.5
5.2 UNIT OPERATES LONG OR CONTINUOUSLY IN COOLING
Container
Hot load
Normal
Defective box insulation or air leak
Repair
Refrigeration system
Shortage of refrigerant
6.3 /6.4
Evaporator coil covered with ice
5.6
Evaporator coil plugged with debris
6.13
Evaporator fan(s) rotating backwards
6.13/6.15
Defective evaporator fan motor/capacitor (single phase
only)
6.16
Air bypass around evaporator coil
Check
Controller set too low
Reset
Compressor service valves or liquid line shutoff valve
partially closed
Open valves
completely
Dirty condenser
6.8
Compressor worn
6.5
Current limit (function code Cd32) set to wrong value
3.3.5
Suction modulation valve lost track of step count
Power cycle
Suction modulation valve malfunction
6.18
Economizer solenoid valve or TXV malfunction
6.12, 6.17
Unloader valve stuck open
6.17
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