McQuay MCC 010C/CR, Manual, Page: 64 / 78

63
For Cooling Only Models Or Heat Pump Models (Cooling Cycle)
Diagnosis By Flow Chart
The following chart are efficient checking procedures for troubleshooting when these fan-coil units, are
coupled with the condensing units using standard wiring. For dual circuited models, perform the procedures
for each circuit.
No Cooling
No Cooling ( Compresor Does Not Start )
No Voltage or Low Voltage
Unit Power
Supply
Evaporator
Fan Motor
Fuse For
Operation
Circuit
Single-Phase
Components Shorted
Connections Loose
Overcurrent
Relay For
Evaporator Fan
High Volage or Low Voltage
Single-Phase
Evaporator Fan
Contactor
Coil Burned
Contact Faulty
Get the Right Voltage
Repair the Power Line
Repair or Replace The Components
Tighten The Connections
Get The Right Voltage
Check The Power Supply To The
Motor : Repair When Necessary
Faulty Fan Motor
Defective Operation Switch
Change The Contactor
Repair The Contacts
Repair Or Change The Motor
Repair Or Replace The Switch
Condenser
Fan Motor
Overcurrent
Relay For
Condenser Fan
Condenser Fan
Contactor
Compressor
Contactor
High Voltage or Low Voltage
Single-Phase
Coil Burnt
Contact Faulty
Fan Motor Faulty
Other Electrical Component Faulty
Coil Burnt
Contact Faulty
Open Compressor Windings
Incorrect Wiring
Get The Right Voltage
Change The Contactor
Change The Contacts
Repair or Change The Motor
Repair or Change If Necessary
Change The Contactor
Repair The Contacts
Change The Compressor
Correct The Wiring
Running
Stop
Tripped
Faulty
Faulty
Faulty
Tripped
Blown
Running
Faulty
Stop
: Faulty : Check : Cause Remedy
Check The Power Supply To The
Motor : Repair When Necessary