Airedale EasiCool 6kW 64kW - Manual (Page 22)

22 EasiCool EZRE Operational Manual 7610207 V1.0.0_02_2013
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EasiCool™ EZRE Precision Air Conditioning
Troubleshooting
General Faults
POSSIBLE CAUSE REMEDY / ACTION
Compressor not operating.
No power to compressor.
Check isolator, fuses, MCBs,
contactor and control circuit wiring.
Seized compressor, possibly due
to lack of oil, broken valve.
Replace compressor - investigate oil
trapping and general installation.
Defective compressor motor.
Check winding resistances -
replace compressor. If burnt out
follow burn out procedure using
suction line burn-out drier.
Compressor phase loss. Check 3 phase supply to compressor.
Klixon out and does not reset.
Sometimes it takes up to 4 hours to
reset. Replace compressor if necessary.
Low pressure switch operated (large or
complete loss of refrigerant charge).
Repair leak and recharge system - if
completely out evacuate before charging.
Condenser fan motor thermal
trip open circuit.
Investigate and correct.
Noisy compressor.
Lack of oil.
Repair leaks if any, add oil if required
but not too much - remember too
much is as bad as too little. Investigate
pipe system and trapping.
Best method to pump down to see
if oil can be encouraged back. If
no oil still, drain compressor and
measure in correct quantity.
Expansion valve stuck in open position
(abnormally cold suction Iine).
Ensure bulb is tight on suction and
superheat is correct (normally 5 to 6°C).
Replace power assembly or
valve as necessary.
Damaged or worn compressor
bearing (excessive knocking).
Replace compressor.
Head pressure too high.
Condenser coil clogged or dirty. Clean condenser coil.
Air or other non-condensable
gas in system.
Evacuate system and re-charge
with new refrigerant.
Overcharge of refrigerant.
Always install new drier
before evacuating.
Reclaim excess refrigerant
from system (liquid only).
Head pressure controller faulty.
Check fan speed controller
- if faulty - replace.
Fan not operating or operating inefficiently. Check motor - if faulty - replace.
Head pressure too low.
Fan operating too fast in low
ambient conditions.
Check fan speed controller
adjustment - if faulty - replace.
Compressor short cycles or
LP cut-out operated.
Dirty filters. Replace.
Dirty or icing evaporator (reduced airflow).
Defrost and/or clean. Check gas
charge and expansion valve.
Lack of refrigerant (bubbles in
sight glass only as indication).
Check for leaks - repair and
recharge system.
Clogged filter drier (pressure /
temperature drop across it).
Replace.
Condenser fan running at full
speed in winter (full airflow).
Check fan speed controller
setting - if faulty - replace.
Start up problems in very low ambients.
Check for low suction pressures on
start-up and fit a low ambient start
kit if required, or check operation
of system if already fitted.