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NOTE
The sealed hermetic system should not be worked on outside the Factory Service Center
:
REFRIGERATION TROUBLESHOOTING
COMPRESSOR WILL NOT START
Problem
1.
Vendor not plugged in.
2.
Tripped breaker or blown fuse.
3.
Faulty wall outlet
4.
Faulty (short or open) power cord.
5.
Improper wiring.
6.
Low voltage
7.
Overload defective
8.
Start relay defective
9.
Compressor has open windings
10.
Defective refrigeration relay
11.
Defective control circuit
12.
Defective door switch
COMPRESSOR TRIPS ON OVERLOAD
Improper voltage
1.
Overload defective
2.
Relay defective
3.
4.
Compressor has shorted winding
NOISY OR VIBRATING UNIT
Components rubbing or touching
1.
each other
2.
Worn or aged grommets
3.
Compressor
UNIT SHORT CYCLES
1.
Defective overload
2.
Faulty condenser fan
3.
Airflow restricted
S T / V T V E N D O R • 3 5 6 8 3 5 6 7 3 5 6 6 3 5 6 5 •
Possible Causes/Actions
Check power cord with a Multi-Meter.
Check the power source with a volt meter. Minimum of 103VAC for 115VAC, 60HZ,
Minimum of 195VAC for 230VAC, 50Hz.
Overload is tripping to fast.
Check overload with a Multi-Meter.
Check start relay with a Multi-Meter.
Check compressor windings with a Multi-Meter.
Switch the controller to Service Mode then verify that the relay turns on by
using the Test Relay menu.
With refrigeration relay turned on in the Test Relay menu. Check relay
terminals 1 to 0 for 24VDC with a Multi-Meter. If power is present relay is bad.
Unplug power to the vendor. Open the power panel. Use insulated jumper wires to
short the wire terminals on Relay 1; between 2 and 4 and between 6 and 8. Restore
power to the vendor. The compressor should start. If it does there is a problem in
the control circuit.
Check for proper door switch operation.
Check voltage for 5-10% above or 5% below machines rated voltage. Check power
source with a Multi-Meter.
Overload tripping to vast.
Check overload with a Multi-Meter.
Relay Won't open after starting.
Check relay with a Multi-Meter.
Check compressor windings with a Multi-Meter.
Check fan blades and motor.
Loose shrouds and harness.
Copper tubing rubbing.
Loose or unsecured parts.
Dirty condenser fan blades.
Check grommets.
Bad valves.
Slugging.
Bad windings (see Figure 21. Compressor Schematic).
Low voltage.
Check overload with a Multi-Meter.
Dirty or blocked condenser coils
Dirty or blocked air filter
Dirty or blocked inlet or outlet screens
23
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4 2 2 0 5 5 7 R e v A
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