Hitachi FSG Series Service Manual page 33

Phenomenon
Power Failure or No Power Supply
Short Circuit between Wires
Melted Fuse for
Power Source
or Activation of
Outdoor Unit
Breaker
Faulty Outdoor Unit Fan
Failure of AC Chopper for
Short Circuit between Wires
Short Circuit of Control Circuit
Melted Fuse for
Control Circuit
or Activation of Magnetic Switch for Comp.
Outdoor Unit
Breaker
Failure of Outdoor Unit Fan
Failure of AC Chopper for
Disconnected
Between Outdoor Unit and
Wires
Insufficient
Contacting or
Power Source Wiring for
Incorrect
Connection
Disconnected Wires to PCB
Faulty PCB
(Outdoor Unit,
Indoor Unit)
Incorrect
Wiring
Cause
Short Circuited Wire to
Ground
Faulty Comp. Motor
Motor
Outdoor Fan
(to Ground)
Faulty Solenoid Coil for
Motor
Motor
Outdoor Fan
Indoor Unit
Outdoor Unit
Faulty PCB
Disconnected Wire
Insufficient Contacting
Incorrect Wiring
TROUBLESHOOTING
Check Item
Measure voltage by tester.
Check for breakage of
insulation.
Measure insulation
resistance.
Measure resistance
between wires and
insulation resistance.
Measure resistance
between wires and
insulation resistance.
Check for breakage of
insulation.
Measure insulation
resistance.
Measure resistance of coil.
Measure resistance
between wires and
insulation resistance
Check continuity of wires.
Check for looseness of
Connection screws.
Check terminal Nos.
Check connections.
Check continuity and
looseness of connection
screws
Check terminal Nos.
1
25
Action
(Turn OFF main switch)
Supply power.
Remove short circuit and
replace fuse.
Remove short circuit to
ground and replace fuse.
Replace comp. and fuse.
Replace outdoor unit fan
motor and fuse.
Replace the AC chopper
for outdoor fan and fuse.
Remove short circuit and
replace fuse.
Remove short circuit and
replace fuse.
Replace magnetic switch
and fuse.
Replace outdoor unit fan
motor and fuse.
Replace the AC chopper
for outdoor fan and fuse.
Replacing wires
Repairing and Tightening
screws and correct wiring.
Correctly connect wires.
Replace it if faulty.
Replacing Wires,
Repairing and Tightening
Screws
Correctly Connect Wires