Hitachi RAS-2-HVNP Service Manual page 213

8. Troubleshooting
Phenomenon
Power failure or power is not ON
Blown out fuse for the power
source or activation of the outdoor
unit breaker
Blown out fuse for control circuit or
activation of outdoor unit breaker
PCB1 Power circuit failure
Disconnected wires insufficient
contacting or incorrect connection
Faulty PCB (outdoor unit, indoor
unit)
Incorrect wiring
N O T E
• *1) In the case that the end terminal resistance (DSW5-1) is set to OFF for H-LINK connection, set the end
terminal resistance to ON when CN8 is disconnected. Set the end terminal resistance to OFF when CN8 is
reconnected.
• *2) Transmission Setting (SW1)
Item Setting Position
SW1 Left Side (for H-LINK/H-LINK II)
• *3)
PCB1 output voltage
Vcc 12 – GND2
Vcc 05 – GND1
Vcc 12 – GND1
Vcc 15 – GND1
Vcc 24 – GND1
Vcc 12T– GND1
• *4) The rotary switch (RSW2) is not available depending on the indoor unit model.
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SMGB0079 rev.0 - 01/2013
Cause
Short-circuit between the wires
Short-circuited wire to ground
Faulty comp. motor
Failure of outdoor unit fan motor
Short-circuit between the wires
Short-circuit of the control circuit
(to ground)
Faulty solenoid coil for the mag-
netic switch for the comp. motor
Failure of outdoor unit fan motor
Between outdoor unit and indoor
unit
Power source wiring for the screws
and the correct wiring outdoor unit
Disconnected wires to PCB
Faulty PCB
Disconnected wire; insufficient
contacting
Incorrect wiring
Check item
Measure the voltage by means of
the tester
Check the insulation material for
breaks
Measure the insulation resistance
Measure the resistance between
the wires and the insulation resist-
ance
Measure resistance between wires
and insulation resistance
Check the insulation material for
breaks
Measure the insulation resistance
Measure the resistance of coil
Measure the resistance between
the wires and the insulation resist-
ance
PCB1 Measure output voltage *1)
Check the continuity of the wires
Check for looseness of the con-
nection screws
Check the terminal Nos.
Check the connections
—
Check the continuity and the
looseness of connection screws
Check the terminal Nos.
Voltage
12 VDC
5 VDC
12 VDC
15 VDC
24 VDC
12 VDC
Action
(Turn OFF the main switch)
Supply the power
Remove the short-circuit and
replace the fuse
Remove short-circuit to ground
and replace the fuse
Replace the comp. and the fuse
Replace the unit fan motor and
the fuse
Remove the short-circuit and
replace the fuse
Remove the short-circuit and
replace the fuse
Replace the magnetic switch and
the fuse
Replace the outdoor unit fan motor
and fuse
Replace PCB1
Replacing wires repairing and
tightening the Power source wir-
ing for the screws and the correct
wiring
Correctly connect the wires
Replace PCB if faulty
Replacing wires, repairing and
tightening the screws
Correctly connect the wires
8