United CoolAir VariCool EZ-Fit Series, Installation, Operation And Maintenance Manual

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Installation, Operation and Maintenance Manual
VariCool EZ-Fit
30
Subject to change without notice.
PROBLEM POSSIBLE CAUSE POSSIBLE SOLUTION
Control is
erratic
1�
Control wiring not installed
correctly
2�
Loose control connections
3�
Broken wiring
1�
Check wiring connections against schematic
2�
Check all connections for tightness
3�
Check wire continuity
Blower fails
to start
1� Controller not set properly
2� Motor failure
3� Defective contactor
4� Overload tripped
5� Controller alarm
6� VFD not functioning properly
1� Turn on and set controller for desired operation
2� Replace motor
3� Replace contactor
4� Check cause and resolve then reset manual overload
(internal overloads will have to reset themselves)
5� Resolve alarm condition
6� Confirm VFD programming and operation
Compressor
fails to start
1� Controller not set properly
2� Loss of refrigerant charge
3� High head pressure
4� Low line voltage
5� Controller alarm
1� Turn on and set controller for desired operation
2� Repair leak, evacuate and recharge refrigerant system
3� Confirm proper fluid flow quantity through condenser
4� Confirm acceptable fluid temperatures entering the
condenser
5� Resolve incoming voltage issue
6� Resolve alarm condition
[Note: Compressor internal overload may require an extended period
of time (1 hour or more) to reset]
Compressor
short cycles
1� Reduced air flow
2� Loss of refrigerant charge
3� Short cycling of conditioned air
4� Drain pan switch open
1� Check filters and coil for any blockages
2� Replace filters if dirty
3� Repair leak, evacuate and recharge refrigerant system
4� Make sure that supply air is not short cycling back into
return air stream
5� Confirm that unit condensate is draining properly
Troubleshooting Guide
Turn OFF power to unit before conducting any troubleshooting, unless the tests
you are performing require system operation Keep hands, clothing and tools
clear of electrical terminals
Make sure to keep hands and clothing clear of any moving belts, blowers and
motors while performing any tests Failure to do so could result in death or
serious bodily injury
Any troubleshooting or test procedures are to be conducted by qualified HVAC
service personnel or electricians only Potentially hazardous situations which
may result in personal injury, equipment or property damage
For operating and troubleshooting instructions for microprocessor controller,
refer to specific controller instructions that accompany the unit
ELECTRICAL
HAZARD
WARNING
CAUTION
INFORMATION