Unit installation

APPENDIX
Troubleshooter's guide
SYMPTOMS POSSIBLE CAUSE CORRECTIVE ACTION
Control differential too small. Reset differential in accordance with job
conditions.
Rapid fluctuations in cooling demand or
chiller is oversized.
Study the load profile carefully and take
sutiable action.
ALARM COMPRESSOR N.# TOO
MANY PUMP DOWN.
Capacity control slider/ solenoid valves not
working properly.
Check slider operation and its solenoid
valves. Ensure that compressors modulate
capacity correctly.
Shortage of refrigerant. Repair leak and recharge.
Insufficient compression - defective
compressor.
Check compressor for internal damage,
repair/ replace compressor.
High suction pressures.
Refer section 10 in this guide and take
corrective action.
Possible controller message: Excessive load or chiller is undersized.
Noncondensables (air) in system. Purge out non condensables.
Wrong expansion valve superheat setting. Adjust superheat setting.
Dirty or defective expansion valve. Clean/ repair/ replace expansion valve.
Restriction in refrigeration circuit (eg:
Clogged filter drier, liquid line solenoid
valve not operating correctly etc).
Locate and remove. (if clogged filter drier,
replace drier elements/cores, if LLSV is
defective - repair/ replace it).
Dirty condenser coil. Clean coil.
Reduced cooler performance (Cooler tubes
fouled retarding heat transfer.)
Check cooler efficiency and Clean water
side of cooler.
Temperature setting too low. Check setting and reset accordingly.
Contactor contacts stuck or weld shut. Replace contacts.
Low suction pressures. Refer section 11 in this guide and take
corrective action.
Possible controller message: Water temperature drops below the
programmed lower limit faster than the unit
can reduce its capacity.
Variation in water flow through cooler.
Locate cause and take corrective action.
ALARM MASTER FREEZE
PROTECTIONAL.
Capacity control slider/ solenoid valves not
working properly.
Check slider operation and its solenoid
valves. Ensure that compressors modulate
capacity correctly.
8. Discharge pressure too high. Refrigerant overcharge. Remove/ purge the excess refrigerant
charge.
Possible Controller message: Non condensables (air) in system. Purge out non condensables or evacuate
the system, as required.
Dirty condenser coil. Clean coil.
Excessive condenser entering air
temperatures.
Check unit location, short circuitng of
condenser discharge air and take suitable
corrective action.
Restriction in discharge line. Locate and take corrective action.
Poor airflow through condenser coils. Check for airflow restrictions and damaged
fins, check for correct fan/ motor operation
and direction of rotation (refer section 16 in
this guide and take corrective action).
9. Discharge pressure too low. Shortage of refrigerant. Repair leak and recharge.
Insufficient compression - defective
compressor.
Check compressor for internal damage,
repair/ replace compressor.
Low suction pressures. Refer section 11 in this guide and take
corrective action.
Low ambient temperatures. Check the setting and operation of fan
cycling for head pressure control.
7. Unit/ Compressors operate
continuously and there is too much
cooling (water temp. too low)
ALARM COMPRESSOR N.X
DISCHARGE PRES. HIGH.
Study the load profile/ demand carefully and
take sutiable action.ALARM MASTER WATER
OVERTEMP.
6. Unit / compressors operate
continuously and system is short of
capacity (water temp. high).
5. Compressor runs ok, but short
cycles. (Too frequent stopping and
starting). Possible Controller
message:
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