Airedale Ultima Compact Condensing Unit 30kW - 450kW - Manual (Page 32)

ULTIMA COMPACT Condensing Units
32
Condensers & Condensing Units
Installation & Maintenance : 6259675 IM V1.4.0 10/2013
Troubleshooting
FAULT POSSIBLE CAUSE REMEDY/ACTION
Unit Will Not Start No power. Check power supply to the controller.
Wired incorrectly. Check wire connections in accordance with
wiring diagram on control box lid.
Loose wires. Check all wires, connections, terminals etc.
Compressor not operating No power to compressor. Check isolator, fuses, MCBs, contactor and
control circuit wiring.
Low pressure cut-out operated (large or
complete loss of refrigerant charge). Recover refrigerant, repair, evacuate and
recharge system.
Condenser fan thermal trip open circuit. Investigate and correct.
Seized compressor, possibly due to lack of
oil. 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 thermal protection device
operated. Check if compressor overheated - possibly
short of refrigerant
Noisy Compressor Expansion valve malfunction (abnormally
cold suction Iine). Ensure feeler bulb is tight on suction and
superheat is correct (normally 5 to 6°C).
Replace power assembly or valve
as necessary.
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.
If no oil still, drain compressor and measure
in correct quantity.
Head Pressure too high/HP
cut-out operated Condenser coil clogged or dirty. Clean condenser.
Overcharge of refrigerant. Normally
troublesome in warm weather. Remove excess refrigerant from system.
Air or other non-condensable gas in system. Evacuate system and re-charge with new
refrigerant.
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.