User Manual

Table Of Contents
© 2018 nVent
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8. Make sure the coils are clean. Then check evaporator “air in” and “air out” temperatures. If the
temperatures are the same:
» Possible loss of refrigerant
» Possible bad valves in the compressor
Repair or Replace
defective part
9. To check for a bad thermostat, turn power to the unit off. Remove the upper access panel and
place both thermostat wires onto one terminal (replace upper access panel for safety). This will
activate the switch in the thermostat. Turn the power on and if all impellers and the compressor
come on, the thermostat needs to be replaced.
SYMPTOMS AND POSSIBLE CAUSES - THERMOSTAT VERSION
SYMPTOM POSSIBLE CAUSE
Unit won’t cool
Clogged ns on coil(s)
Dirty lter
Impellers not running
Compressor not running
Compressor runs, but has bad valves
Loss of refrigerant
Compressor tries to start but won’t run
Low line voltage at start. Should be +/-10% rated voltage.
Compressor motor stuck
Bad contactor
Bad overload switch
Bad run/start capacitor
Unit blows breakers
Undersized breaker/fuse or not time delayed
Short in system
Getting water in enclosure
Drain plugged
Drain tube kinked
Enclosure not sealed (allowing humidity in)
Mounting gasket damaged
For additional technical support, contact nVent Equipment Protection at 800-896-2665.