TROUBLESHOOTING & SERVICING REFRIGERATION SYSTEM

 

PROBLEM

 

POSSIBLE CAUSE

 

REMEDY

7.

Start capacitor open or shorted

1.

Relay contacts not opening

1.

Replace relay.

 

blown.

 

properly.

2.

 

 

 

2.

Prolonged operation on start cycle

 

 

 

 

due to:

 

a. Determine reason and correct.

 

 

 

a. Low voltage to unit.

 

 

 

 

b. Improper relay.

 

b. Replace.

 

 

 

c. Starting load too high.

 

c. Correct by using pump down

 

 

 

 

 

arrangement if necessary.

 

 

3.

Excessive short cycling.

3.

Determine reason for short cycling

 

 

 

 

 

(see 5 above) and correct.

 

 

4.

Improper capacitor.

4.

Determine correct size and

 

 

 

 

 

replace.

 

 

 

 

 

 

8.

Run capacitor open, shorted or

1.

Improper capacitor.

1.

Determine correct size and

 

blown.

 

 

 

replace.

 

 

2.

Excessively high line voltage

2.

Determine reason and correct.

 

 

 

(110% of rated-max.)

 

 

 

 

 

 

 

 

9.

Relay defective or burned out.

1.

Incorrect relay.

1.

Check and replace.

 

 

2.

Incorrect mounting angle.

2.

Remount relay in correct position.

 

 

3.

Line voltage too high or too low.

3.

Determine reason and correct.

 

 

4.

Excessive short cycling.

4.

Determine reason (see 5 above)

 

 

 

 

 

and correct.

 

 

5.

Relay being influenced by loose

5.

Remount rigidly.

 

 

 

vibrating mounting.

6.

Replace with proper capacitor.

 

 

6.

Incorrect run capacitor.

 

 

 

 

 

 

 

 

 

 

10.

Product zone temperature too

1.

Control setting too high.

1.

Reset control.

 

high.

2.

Inadequate air circulation.

2.

Rearrange product load to

 

 

 

 

 

improve air circulation.

 

 

 

 

 

11. Suction line frosted or sweating.

1.

Overcharge of refrigerant.

1.

Correct charge.

 

 

2.

Evaporator fan not running.

2.

Determine reason and correct.

 

 

3.

If remote model, expansion valve

3.

Replace.

 

 

 

stuck open.

4.

Readjust valve or replace with

 

 

4.

If remote model expansion valve

 

 

 

is passing excess refrigerant or is

 

properly sized valve.

 

 

 

oversized.

 

 

 

 

 

 

 

 

12.

Liquid line frosted or sweating.

1.

Restriction in dehydrator or

1.

Replace part.

 

 

 

strainer.

2.

Open valve fully.

 

 

2.

Liquid shut-off (king valve)

 

 

 

partially closed.

 

 

 

 

 

 

 

 

13.

Noisy condensing unit.

1.

Loose parts or mounting.

1.

Find and tighten.

2.

Tubing rattle.

2.

Reform to be free of contact.

 

 

 

 

3.

Bent fan blade causing vibration.

3.

Replace blade.

 

 

4.

Fan motor bearings worn.

4.

Replace motor.