Refrigeration Trouble Shooting Chart - Freezer - True GDM Series Technical & Service Manual

REFRIGERATION TROUBLESHOOTING CHART
Freezer
REFRIGERATION TROUBLESHOOTING CHART
(FREEZER)
PROBLEM Cabinet is running warm.
Can you hear the compressor running?
N O If nothing is running and cabinet is warm check to make sure cabinet is plugged in and then check circuit
breaker. GDM cabinet lights will not come on until cabinet reaches 20 degrees but on T series cabinets lights
will work when you open the door at any temperature. All freezers have a fan delay that will not allow the
evaporator fans to start before the coil gets to 15 degrees.
Remove the grill covering the condensing unit. Check the defrost timer to see if cabinet is in defrost. Do not
turn dial on defrost timer, take a pencil and mark a spot on the outer dial and watch this to see if timer is
working. This should take no more than 10 minutes to verify. While waiting, look to see if the condenser coil
(looks like a car radiator) is clean. If coil is dirty clean with a brush and a vacuum or compressed air.
(CONDENSER COILS SHOULD BE CLEANED MONTHLY)
If cabinet is not in defrost and the compressor and condenser fan motor is not running, unplug the condensing
unit and check the voltage at the compressor receptacle. The voltage should be within 10% on a 115 volt
compressor and within 5% on a 208 /230 volt compressor.
Any voltage less than that unplug cabinet and remove the temperature control from the evaporator housing and
check out control. Control could be stuck open or be pitted due to low voltage or short cycling.
Refer to
Temperature Control Change-Out Instructions, page 39-41.
• T h e re is a wiring diagram on the back of the electrical box cover plate. Use this to help you
t roubleshoot.
Y E S The compressor is running and cabinet is warm. Does the evaporator coil have an ice build up on it? If
so follow above directions on how to verify if timer is advancing. If it is manually turn timer and put freezer
into defrost to check defrost heaters.
After ice build up is gone restart cabinet if box starts to freeze properly cabinet may not have enough defrost
times. Set timer for 4 defrosts a day. You may also want to check out defrost heater voltage and amperage at
this time to verify that there is not a heater or voltage problem.
If the compressor is running and there is no ice build up on the evaporator coil, install gauges on the suction
and discharge side of the system and check the system operating pressures.
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