Airedale Condensing Units (CU) 3kW - 80kW - Manual (Page 23)

Condensing Units
CUS 15 - 60 / HCU 20 – 30D
Chillers & Condensing Units
Installation & Maintenance:Part No: 6259592 IM 07/14
23
Troubleshooting
REFRIGERATION
FAULT POSSIBLE CAUSE REMEDY / ACTION
Head pressure too high. Condenser coil blocked or dirty Clean condenser coil
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. LP switch set too high. Adjust/replace as appropriate.
Lack of refrigerant (bubbles in sight glass
only as indication). Check for leaks – reclaim refrigerant,
repair, evacuate and recharge system.
Clogged filter drier (pressure / temperature
drop across it). Replace once the cause has been
identified and rectified.
Condenser fan running at full speed in
winter (full airflow). Check fan speed controller setting - if faulty
- replace.
Suction Pressure too low. Low evaporator airflow (not Airedale Unit). Check fan motors, belts and drives.
Flash gas (bubbles in sight glass) at
expansion valve. Investigate for refrigerant leaks, repair and
re-charge system.
Clogged filter drier (pressure / temperature
drop across it). Replace.
Obstruction in liquid line solenoid valve. Pump down, inspect, clean or replace.
Obstruction in expansion valve. Pump down, inspect, clean or replace.