TROUBLESHOOTING & SERVICING REFRIGERATION SYSTEM

 

PROBLEM

 

POSSIBLE CAUSE

 

REMEDY

1.

Condensing unit fails to start - no

1.

Line disconnect switch open.

1.

Close start or disconnect switch.

 

hum.

2.

Fuse removed or blown.

2.

Replace fuse.

 

 

3.

Overload protector tripped.

3.

Determine reason and

 

 

4.

Control stuck in open position.

 

correct/replace control.

 

 

4.

Repair or replace control.

 

 

5.

Wiring improper or loose.

5.

Check wiring against diagram.

 

 

 

 

 

 

2.

Compressor fails to start -

1.

Improperly wired.

1.

Check wiring against diagram.

 

hums and trips on overload

2.

Low voltage to unit.

2.

Determine reason and correct.

 

protector.

3.

Starting capacitor defective.

3.

Determine reason and replace.

 

 

4.

Relay failing to close.

4.

Determine reason and

 

 

5.

Compressor motor has a winding

 

correct/replace if necessary.

 

 

5.

Replace compressor.

 

 

 

open or shorted.

6.

Replace compressor.

 

 

6.

Internal mechanical trouble in

 

 

 

compressor.

 

 

 

 

 

 

 

 

3.

Compressor starts, but fails

1.

Improperly wired.

1.

Check wiring against diagram.

 

to switch off of “start” winding.

2.

Low voltage to unit.

2.

Determine reason and correct.

 

 

3.

Relay failing to open.

3.

Determine reason and

 

 

4.

Run capacitor defective.

 

correct/replace if necessary.

 

 

4.

Determine reason and replace.

 

 

5.

Excessively high discharge

5.

Check discharge shut-off valve,

 

 

 

pressure.

 

possible overcharge, or

 

 

6.

Compressor motor has a winding

 

insufficient cooling on condenser.

 

 

6.

Replace compressor.

 

 

 

open or shorted.

 

 

 

 

7.

Internal mechanical trouble in

7.

Replace compressor.

 

 

 

compressor.

 

 

 

 

 

 

 

 

4.

Compressor starts and runs,

1.

Additional current passing through

1.

Check wiring diagram.

 

but short cycles on overload

 

overload protector.

 

 

 

protector.

2.

Low voltage to unit (or

2.

Determine reason and correct.

 

 

 

unbalanced if three phase.)

 

 

 

 

 

 

 

3.

Overload protector defective.

3.

Check current , replace protector.

 

 

4.

Run capacitor defective.

4.

Determine reason and replace.

 

 

5.

Excessive discharge pressure.

5.

Check ventilation, restrictions in

 

 

 

 

 

cooling medium, restrictions in

 

 

6.

Suction pressure too high.

 

refrigeration system.

 

 

6.

For salad models, temperature

 

 

 

 

 

control differential set to close-

 

 

 

 

 

increase differential.

 

 

7.

Compressor too hot - return gas.

7.

Check refrigerant charge (fix leak)

 

 

 

 

 

add if necessary.

 

 

8.

Compressor motor has a winding

8.

Replace compressor.

 

 

 

shorted.

 

 

 

 

 

 

 

 

5.

Compressor runs but short

1.

Overload protector.

1.

See (4) above.

 

cycles on...

2.

Thermostat.

2.

Differential set too close - widen.

 

 

3.

High pressure cut-out due to:

3.

a. Check air or water supply to

 

 

 

a. Insufficient air or water supply.

 

 

 

 

b. Overcharge.

 

condenser-correct.

 

 

 

 

b. Recover refrigerant and recharge.

 

 

 

c. Air in system.

4.

 

 

 

4.

Low pressure cut-out due to:

a. Replace.

 

 

 

a. Liquid line solenoid leaking.

 

 

 

 

b. Compressor valve leak.

 

b. Replace.

 

 

 

c. Undercharge.

 

c. Fix leak, add refrigerant.

 

 

 

d. Restriction in expansion

 

d. Replace device.

 

 

 

device.

 

 

 

 

 

 

 

 

6.

Condensing unit operates for

1.

Shortage of refrigerant.

1.

Fix leak, add charge.

 

prolonged periods or

2.

Control contacts stuck or frozen

2.

Clean contacts or replace control.

 

continuously.

 

closed.

3.

Allow unit sufficient time for

 

 

3.

Excessive heat load placed into

 

 

 

cabinet.

 

removal of latent heat.

 

 

4.

Prolonged or too frequent door

4.

Plan or organize schedule to

 

 

 

openings.

 

correct condition.

 

 

5.

Evaporator coil iced.

5.

Defrost.

 

 

6.

Restriction in refrigeration

6.

Determine location and remove.

 

 

 

system.

 

 

 

 

7.

Dirty condenser.

7.

Clean condenser.

 

 

8.

Filter dirty.

8.

Clean or replace.

 

 

 

 

 

 

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Victory Refrigeration V-Series manual Troubleshooting & Servicing Refrigeration System