115
8. TROUBLESHOOTING
ENGLISH
Problems
Cause
Action
Discharge temper-
ature is excessively
high
1) Air or non condensing gas exists in the sys-
tem
2) Cooling water inlet temperature is high or
cooling water flow rate passing through con-
denser is insufficient.
3) Condenser tubes are covered with scales,
lime, corrosion, etc.
4) Water pump defect
5) Excess refrigerant which causes liquid re-
frigerant to be concentrated to condenser
tubes
6) Condenser's gas inlet valve is not fully open
7) Suction pressure is higher than normal.
1) Discharge from condenser
2) Control the water system, check operation
status of cooling tower fan, check filter in
the pipeline
3) Clean tubes
4) Check cooling water pump
5) Discharge excessive amount of refrigerant
6) Open valve
7) Refer to 'Suction pressure excessively high'
Discharge temper-
ature is excessively
low
1) Excessive flow or low temperature of the
water which passes through condenser
2) Oil bubble caused by the liquid refrigerant
flow from evaporator to compressor
3) Liquid outlet valve of condenser is leaking.
4) Suction pressure is lower than normal.
5) Due to insufficient amount of refrigerant,
gas refrigerant is entering into liquid pipe.
1) Adjust water valve, or control break valve:
Check operation condition of cooling tower
fan
2) Check and adjust expansion valve, check
whether the sensor on the inlet pipe is fixed
firmly and insulated, and check whether
cooling water's inlet temperature is higher
than limit value.
3) Check condenser operation status, if re-
quired, replace outlet valve.
4) Refer to 'Suction pressure is excessively
low'
5) Charge sufficient amount of refrigerant.
Suction pressure is
excessively high
1) Discharge pressure is excessively high.
2) Refrigerant is overcharged.
3) Liquid refrigerant flowing from evaporator to
compressor
4) Defective insulation in chilled water pipe
1) Refer to 'Discharge pressure is excessively
low'
2) Discharge excessive amount of refrigerant
3) Check and adjust expansion valve, check
whether the sensor on the inlet pipe is fixed
firmly and insulated, and check whether
cooling water's inlet temperature is higher
than limit value.
4) Check insulation condition of pipeline
Suction pressure is
excessively low
1) Condenser's liquid outlet valve is not fully
open
2) Liquid pipe or suction pipe is blocked.
3) Defective expansion device or improper ad-
justment
4) Insufficient amount of refrigerant
5) Excessive amount of oil in the lubrication
cycle
6) Chiller inlet temperature is lower than the
standard value
7) Insufficient amount of chilled water passing
through evaporator
8) Discharge pressure is excessively low.
1) Open valve
2) Check refrigerant filter
3) Control the degree of superheat accurately
and check whether there is leakage in tem-
perature package.
4) Refrigerant leakage test
5) Check oil amount
6) Set temperature control
7) Pressure loss in chilled water pipeline
8) Adjust water system valve
High pressure
valve operated
1) Insufficient amount of cooling water
2) Condenser is blocked, inlet valve interrupted
3) High pressure prevention valve setting is ab-
normal.
4) Charged amount of refrigerant is excessive.
1) Check water system valve
2) Check facts about tube of condenser and
water valve Identitify the cause of the pres-
sure
3) Check the value of the setting
4) Check charged amount of refrigerant
8-2. Chiller problems and actions
Summary of Contents for LCWW
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