7. Start capacitor open or shorted
blown.
8. Run capacitor open, shorted or
blown.
9. Relay defective or burned out.
10. Product zone temperature too
high.
11. Suction line frosted or sweating.
12. Liquid line frosted or sweating.
13. Noisy condensing unit.
1. Relay contacts not opening
properly.
2. Prolonged operation on start cycle
due to:
a. Low voltage to unit.
b. Improper relay.
c. Starting load too high.
3. Excessive short cycling.
4. Improper capacitor.
1. Improper capacitor.
2. Excessively high line voltage
(110% of rated-max.)
1. Incorrect relay.
2. Incorrect mounting angle.
3. Line voltage too high or too low.
4. Excessive short cycling.
5. Relay being influenced by loose
vibrating mounting.
6. Incorrect run capacitor.
1. Control setting too high.
2. Inadequate air circulation.
1. Overcharge of refrigerant.
2. Evaporator fan not running.
3. If remote model, expansion valve
stuck open.
4. If remote model expansion valve
is passing excess refrigerant or is
oversized.
1. Restriction in dehydrator or
strainer.
2. Liquid shut-off (king valve)
partially closed.
1. Loose parts or mounting.
2. Tubing rattle.
3. Bent fan blade causing vibration.
4. Fan motor bearings worn.
1. Clean contacts or replace relay if
necessary.
2.
a. Determine reason and correct.
b. Replace.
c. Correct by using pump down
arrangement if necessary.
3. Determine reason for short cycling
(see 5 above) and correct.
4. Determine correct size and
replace.
1. Determine correct size and
replace.
2. Determine reason and correct.
1. Check and replace.
2. Remount relay in correct position.
3. Determine reason and correct.
4. Determine reason (see 5 above)
and correct.
5. Remount rigidly.
6. Replace with proper capacitor.
1. Reset control.
2. Rearrange product load to
improve air circulation.
1. Correct charge.
2. Determine reason and correct.
3. Clean valve of foreign particles.
Replace if necessary.
4. Readjust valve or replace with
smaller valve.
1. Replace part.
2. Open valve fully.
1. Find and tighten.
2. Reform to be free of contact.
3. Replace blade.
4. Replace motor.
PROBLEM
POSSIBLE CAUSE
REMEDY
TROUBLESHOOTING & SERVICING REFRIGERATION SYSTEM
