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9. Symptom: Low refrigerant discharge pressure
Possible Causes
Suction shut off valve partially closed
Insufficient refrigerant in chiller
Compressor operating unloaded
Low ambient conditions
Low suction pressure
Condenser pressure regulating valve not properly adjusted
Fan cycling controls not properly set
10. Symptom: High refrigerant discharge pressure
Possible Causes
System overcharged with refrigerant
Dirty tube and fin surface
Non-condensables in chiller
Fan cycling controls not properly set
Condensing fans not operating
Restricted bypass line
Discharge shut off valve partially closed
Condenser is undersized
High ambient conditions exist
11. Symptom: Low chilled water temperature
Possible Causes
Temperature controllers set too low
Water velocity through evaporator too low
Temperature controllers malfunctioning
12. Symptom: High chilled water temperature
Possible Causes
Load higher than capacity of chiller
Loss of refrigeration charge
Fouled evaporator
Obstructed flow through evaporator
ARTC-SVX001B-EN
Potential Solutions
Open valve
Check for leaks. Repair and add refrigerant as needed
See failure of compressor to unload or load up below
Check condenser rating tables
See low pressure below
Refer to OEM manufacturer manual for default settings; check
equipment room ambient temperature
Reset cut-in, cut-out settings to conform to design specifications
Potential Solutions
Remove excess refrigerant
Clean with compressed air or water spray, use fin comb if fins are
bent
Purge non-condensables.
Reset fan cycle setting; replace motor controller fuse
Reset fan cycle setting; replace motor controller fuse
Check valves obstructed; flush line; blow out line with dry nitrogen
gas
Open valve
Check condenser rating tables with operating parameters
Check condenser rating tables with operating parameters
Potential Solutions
Reset temperature controllers to correct design specifications
Clean strainer; check pump, VFD, and differential pressure settings
Replace temperature sensor
Potential Solutions
Refer to chiller design specifications
Pressure test refrigeration system
Reverse flush evaporator; check strainer for debris
Reverse flush evaporator; check strainer for debris; check VFD,
pump, valves
C C h h i i l l l l e e r r T T r r o o u u b b l l e e s s h h o o o o t t i i n n g g
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