035-19569-101 (0109)
8-1
GB
8 TROUBLSHOOTING
Fault Possible Cause Remedy
1. SYMPTOM: Abnormally High Discharge Pressure
Temperature difference between
condensing temperature
and condenser leaving liquid
temperature higher than normal.
Air in condenser. Bleed cooling water circuit.
High discharge pressure. Condenser tubes dirty or scaled. Clean condenser tubes. Check
water treatment.
High condenser water temperature. Reduce condenser water inlet
temperature. (Check cooling tower
and water circulation.)
Temperature difference between
condenser entering liquid
and condenser leaving liquid
higher than normal, with normal
evaporator pressure.
Insuffi cient condensing water fl ow. Increase the water fl ow through the
condenser to correct value.
2. SYMPTOM: Abnormally Low Suction Pressure
Temperature difference between
leaving chilled water and
refrigerant in evaporator greater
than normal with high discharge
temperature.
Insuffi cient charge of refrigerant. Check for leaks and charge
refrigerant into system.
Variable orifi ce problem. Remove obstruction.
Temperature difference between
leaving chilled water and
refrigerant in the evaporator
greater than normal with normal
discharge temperature
Evaporator tubes dirty or restricted. Clean evaporator tubes.
Temperature of chilled water too
low with low motor current.
Insuffi cient load for system
capacity.
Check pre-rotation vane motor
operation and setting of low water
temperature cut-out.
3. SYMPTOM: High Evaporator Pressure
High chilled water temperature. Pre-rotation vanes fail to open. Check the pre-rotation vane motor
positioning circuit.
System overload. Be sure the vanes are wide open
(without overloading the motor)
until the load decreases.
4. SYMPTOM: No Oil Pressure when System Start Button Pushed
Low oil pressure displayed on
control centre; compressor will not
start.
Oil pump running in wrong
direction.
Check rotation of oil pump
(Electrical Connections).
Oil pump not running. Troubleshoot electrical problem
with oil pump VSD.
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