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LogiCool InRak™
IT Cooling
84 InRak™ Technical Manual 7462807 V1.11.0_04_2016
Troubleshooting
FAULT
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.