Troubleshooting
Service Manual
166
Initial troubleshooting
SMGB0066 rev.0 - 12/2009
7.1. InITIAl TroUBlESHooTInG
7.1.1. Unit and System controller - Power Supply failure
• The lEd and the 7-segment display are not indicated.
• not operated.
If the fuses are blown out or a circuit breaker is activated, investigate the cause of the overcurrent and take the
necessary action.
observed failure
Cause
Check item
Action (Turn off the main
switch)
Power failure or power is not ON
Measure the voltage using a
voltmeter
Supply the power
Blown out fuse or activation of
the breaker at the power source
Accidental grounding for live cables
Measure the insulation
resistance
Remove the cause of the short
circuit and replace the fuse
Failure of compressor motor
Measure the interphase
resistance, insulation
resistance
Replace compressor and fuse
Failure of fan motor
Replace fan motor and fuse
Blown out fuse at the control
circuit
Live cables short circuit
Check for any un-insulated
part of the wires
Remove the cause of the short
circuit and replace the fuse
Short circuit of the control circuit to
earth
Measure the insulation
resistance
Remove the cause of the short
circuit and replace the fuse
Failure of the
magnetothermic
switch for the
compressor
Insufficient
contact
Check for magnetothermic
switch to activate correctly
Replace magnetothermic
switch and fuse
Coil failure
Measure coil resistance
Failure of the
magnetothermic
switch for the pump
Insufficient
contact
Check for magnetothermic
switch to activate correctly
Replace magnetothermic
switch and fuse
Coil failure
Measure coil resistance
Failure of auxiliary
relay
Insufficient
contact
Check for magnetothermic
switch to activate correctly
Replace auxiliary relay and
fuse
Coil failure
Measure coil resistance
Failure of solenoid
valve coil
Coil failure
Measure coil resistance
Replace coil and fuse
Short circuit in PCB
Check for the existance of
any conductive contaminants
Remove the particles and
replace fuse
Oil heater failure
Meassure resistance
Replace heater and fuse
Failure of freeze protection heater for
water piping
Meassure resistance
Replace heater and fuse
Failure of the transformer
Check the transformer
voltage output
Replace the transformer