Specifications

175
The most common causes of air conditioner failure to “start” are :
a) Voltage not within ±10% of rated voltage.
b) Power supply interrupted.
c) Improper control settings.
d) Air conditioner is disconnected from main power source.
e) Fuse blown or circuit breaker off.
By Means of Diagnostic Flow Chart:
Generally, there are two kinds of problems, i.e. starting failure and insufficient cooling/heating. “Starting failure”
is caused by electrical defect while improper application or defects in refrigerant circuit causes “Insufficient
cooling / heating”.
i) Diagnosis of Electric Circuit
: Faulty : Check : Cause : Remedy
No Cooling/heating (Unit fails to start)
Evaporator
Fan Motor
Stop
Unit Power
Supply
Fuse For
Operation
Circuit
Overcurrent
RelayFor
Evaporator Fan
Evaporator FAn
Contactor
Running
Condenser
Fan Motor
Stop
Overcurrent
Relay For
Condenser Fan
Condenser Fan
Contactor
Running
Tripped
Tripped
Faulty
Faulty
Faulty
Blown
Faulty
Compressor
Contactor
No Voltage or Low Voltage
Wrong Phase/Missing Phase
Components Shorted
Connections Loose
High or Low Voltage
Wrong Phase/Missing Phase
Coil Burnt
Contact Family
Faulty Fan Motor
Defective Operation Switch
High Voltage or Low Voltage
Wrong Phase/Missing 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
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
Change The Contactor
Repair The Contacts
Repair Or Replace The Switch
Repair Or Change The Motor
Get The Right Voltage
Check The Power Supply To The
Motor : Repair When Necessary
Change The Contactor
Change The Contacts
Repair or Change If Necessary
Repair or Change The Motor
Change The Contacts
Change The Compressor
Correct The Wiring
Change The Contactor