31
General Troubleshooting (continued)
Problem
Possible Cause
Remedy
Insufficient
cooling
(temperature
continues to
rise above set
point)
Process load too high
Check to make sure chiller is properly sized for process load
Coolant flow through evaporator out of range
Adjust flow to proper level
Insufficient condenser cooling
See high refrigerant pressure
Compressor loader solenoid valve
Check microprocessor output
Replace compressor loader solenoid
Replace control relay
Refrigeration circuit problem
Contact refrigeration service technician
Thermocouple
Replace if faulty
Microprocessor input card, process sensor
Replace if faulty
Erratic
temperature
control
Low coolant flow through evaporators
Adjust flow to proper level
Overloading of chiller capacity
Check to make sure chiller is properly sized for process load
Thermocouple
Replace if faulty
Microprocessor input card, process sensor
Replace if faulty
Temperature
values
unsteady or
out of range
Loose thermocouple wire connections
Tighten terminal screw
Microprocessor input card
Replace if faulty
LEDs on OKC
not on
Control power not available at power supply
Check power at power supply, check power supply
Display not
updating
Loss of communication
Check communication cable.
Microprocessor fault
Replace if faulty
Screen
objects not
working
Microprocessor/display fault
Replace if faulty
Screen
objects are
not visible
Correct power is not applied
Verify power connections
Microprocessor/display fault
Replace if faulty
Chiller will
not start
No demand
Increase load on chiller
Compressor Anti-Cycle Timer Active
Allow timer to expire
Alarm fault active
Clear alarm condition and reset alarm
If compressor motor module fault, cycle power
