Kolpak PR - Section 7 Troubleshooting; Evaporator Troubleshooting

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Section 7
Troubleshooting
Evaporator Troubleshooting
Problem
Possible Cause
Corrective Action
Fan(s) will not operate.
Main switch open
Close switch
Blown fuse(s)
Replace fuse(s). Check for short
circuits or overload conditions.
Defective motor
Replace motor.
Defective timer or defrost thermostat
Replace defective component.
Unit in defrost cycle
Wait for completion of cycle.
Walk-in temperature too high.
Thermostat set too high
Adjust thermostat.
Superheat too high
Adjust thermal expansion valve.
System low on refrigerant
Locate and repair leak, recover,
evacuate and recharge.
Coil iced up
Manually defrost coil. Check defrost
controls.
Ice accumulating on ceiling around
evaporator and/or on fan guards,
venturi, or blades.
Defrost duration is too long
Adjust defrost termination thermostat
(if adjustable).
Fan delay not delaying fans after
defrost period
Replace defective defrost thermostat.
Defective defrost thermostat or timer
Replace defective component.
Too many defrost cycles per day
Reduce number of defrost cycles per
day.
Frost on coil after defrost cycle.
Coil temperature not getting above
freezing point during defrost
Check heater operation
Not enough defrost cycles per day
Adjust timer for more defrost cycles
per day
Defrost cycle too short
Adjust timer for longer cycle, check
defrost thermostat mounting
Defective timer or defrost thermostat
Replace defective component.
Ice accumulating in drain pan.
Defective heater
Replace heater.
Unit not pitched properly
Check and adjust.
Drain line plugged
Clean drain line.
Defective drain line heater
Replace heater.
Defective timer or thermostat
Replace defective component.