McQuay MCC 010C/CR Manual page 64

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 )
Evaporator
Fan Motor
Running
Evaporator Fan
Evaporator Fan
Condenser
Fan Motor
Condenser Fan
Running
Condenser Fan
: Faulty
Stop
Faulty
Unit Power
Supply
Fuse For
Blown
Operation
Circuit
Tripped
Overcurrent
Relay For
Faulty
Contactor
Stop
Tripped
Overcurrent
Relay For
Faulty
Contactor
Faulty
Compressor
Contactor
: Check
No Voltage or Low Voltage
Single-Phase
Components Shorted
Connections Loose
High Volage or Low Voltage
Single-Phase
Coil Burned
Contact Faulty
Faulty Fan Motor
Defective Operation Switch
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
63
: Cause
Repair or Replace The Components
Tighten The Connections
Get The Right Voltage
Check The Power Supply To The
Motor : Repair When Necessary
Change The Contactor
Repair Or Change The Motor
Repair Or Replace The Switch
Get The Right Voltage
Check The Power Supply To The
Motor : Repair When Necessary
Change The Contactor
Repair or Change The Motor
Repair or Change If Necessary
Change The Contactor
Change The Compressor
Remedy
Get the Right Voltage
Repair the Power Line
Repair The Contacts
Change The Contacts
Repair The Contacts
Correct The Wiring