Table of Contents
Advertisement
Troubleshooting – Refrigeration Circuit
Symptom
Possible Cause
Refrigerant overcharge.
Condenser fan motor defective.
Compressor
starts but
Condenser coil inlet obstructed or dirty.
cuts out on
high pressure
Air or non-condensables in system.
switch
Defective high pressure switch.
High pressure
activates at
600 PSIG
Restriction in discharge or liquid line.
Condensing fan relay not pulling in.
Low voltage.
Sustained high discharge pressure.
High suction and discharge pressures.
Compressor
Defective compressor overload.
cuts out
on thermal
overload
Improper refrigerant charge.
Improperly wired.
Loose wiring.
Defective start relay.
Motor windings damaged.
Improperly wired.
Low line voltage.
Compressor
Loose wiring.
hums, but will
Defective start relay.
not start
Motor winding damaged.
Internal compressor mechanical damage.
Refrigerant overcharge.
Liquid floodback.
Tubing rattle.
Compressor
noisy or
Scroll compressor rotating in reverse.
vibrating
(3-phase)
Damaged compressor.
Improper mounting on unit base.
Always have a completed Pre-Start-Up Checklist and Start-Up Checklist prior to requesting parts or service
information.
Corrective Action
Check pressures, charge by subcooling.
Check fan motor.
Check coil and clearances. Clean coil if necessary.
Check high side equalized pressures, check thermal expansion
valves.
Replace.
Check refrigerant line pressures, check thermal expansion
valves, replace any defective component.
Replace.
Check voltage.
Check running amperage and conditions described under "low
suction pressure" symptoms.
Check thermal expansion valve setting, check for air in system.
Check air conditions and cfm.
If compressor is hot, allow compressor to cool for two hours.
Recheck for open circuit.
Check subcooling.
Review wiring schematics.
Check all connections.
Replace relay.
Verify amp draw.
Review wiring schematics.
Check voltage.
Check all connections.
Replace relay.
Verify amp draws. Replace compressor if necessary.
Replace.
Check pressures and subcooling.
Check thermal expansion valve setting. Check for refrigerant
overcharge.
Dampen tubing vibration by taping or clamping. Carefully bend
tubing away from contact where possible.
Check high and low side pressures during operation to confirm.
Rewire for opposite rotation.
Replace the compressor.
Check that compressor is properly isolated and mounting bolts
are tight.
VersiVent Energy Recovery Ventilator
37
Advertisement
Table of Contents
