I
1
6
TROUBLESHOOTING
COMPLAINT
SYMPTOMS
CAUSE
SOLUTION
7 Compressor does
not pump
Minimal difference in pressure
between high side and low side
of system, when compressor
motor has power
Broken suction valves
Change compressor
Broken discharge line
Change compressor
Internal pressure safety
valve stuck open
Check item 13 and change
compressor if
necessary
8 Compressor will
not start
Blown fuse or open disconnect
Short circuit or other
electrical failure
Check electrical circuit
and wiring
Tripped or damaged overload
Overheating or overcurrent Wait 2-3 hours for overload
to reset and check
refrigerant charge or power
quality to the compressor
Open pressure switch
Loss of refrigerant
charge
Check for leaks, repair
and recharge
Loose wires
Vibration, bad crimping or
under-torque
Check terminals at
compressor, contactor and
wiring in general
Motor seized
Low oil level or phase
reversal
Check oil level. Restart 3-ph
compressor by switching
2 phases; replace if it does not
restart
9 Compressor starts
but start relay does
not drop out
High running current,
overload trips
Incorrect wiring of start
components
Check wiring
Incorrect or defective
start relay
Confirm operation, model
and make
Incorrect or defective start
capacitor
Confirm integrity and
specs, check if fitted with
discharge resistance
Incorrect or defective
run capacitor
Confirm integrity and
specs
Low voltage
Fix undervoltage protection
10 Compressor
runs but cuts
out on
overload
Internal overload tripping
MUST WAIT 2-3 HOURS TO
CHECK IF IT WILL RESET
Excessive head pressure
due to dirty condenser
or lack of condenser air
or water flow
See item 2 above
Low voltage or unbalanced Fix undervoltage protection
Faulty electrical connections
causing single phasing or
high current surges
Remake the connections
Sticking start relay on
single phase machines
leaving start cap on circuit
Replace relay and ensure start
cap is fitted with a discharge
resistance
