Hitachi RAS-(3-6)HVNC1(E) - Page 240

8 Troubleshooting
226
SMGB0087 rev.0 - 12/2013
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
Power failure or power is not ON
Measure the voltage by means
of the tester
Supply the power
Blown out fuse for the power
source or activation of the
outdoor unit breaker
Short-circuit between the wires
Check the insulation material
for breaks
Remove the short-circuit and
replace the fuse
Short-circuited wire to ground
Measure the insulation
resistance
Remove short-circuit to ground
and replace the fuse
Faulty compressor motor
Measure the resistance
between the wires and the
insulation resistance
Replace the compressor and
the fuse
Failure of outdoor unit fan
motor
Measure resistance between
wires and insulation resistance
Replace the unit fan motor and
the fuse
Blown out fuse for control
circuit or activation of outdoor
unit breaker
Short-circuit between the wires
Check the insulation material
for breaks
Remove the short-circuit and
replace the fuse
Short-circuit of the control
circuit (to ground)
Measure the insulation
resistance
Remove the short-circuit and
replace the fuse
Faulty solenoid coil for the
magnetic switch for the com-
pressor motor
Measure the resistance of coil
Replace the magnetic switch
and the fuse
Failure of outdoor unit fan
motor
Measure the resistance
between the wires and the
insulation resistance
Replace the outdoor unit fan
motor and fuse
PCB1 Power circuit failure
PCB1 Measure output voltage
*1)
Replace PCB1
Disconnected wires insufcient
contacting or incorrect
connection
Between outdoor unit and
indoor unit
Check the continuity of the
wires
Check for looseness of the
connection screws
Check the terminal numbers
Replacing wires repairing and
tightening the power source
wiring for the screws and the
correct wiring
Power source wiring for the
screws and the correct wiring
outdoor unit
Faulty PCB (outdoor unit,
indoor unit)
Disconnected wires to PCB Check the connections Correctly connect the wires
Faulty PCB — Replace PCB if faulty
Incorrect wiring
Disconnected wire; insufcient
contacting
Check the continuity and
the looseness of connection
screws
Replacing wires, repairing and
tightening the screws
Incorrect wiring Check the terminal numbers Correctly connect the wires
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
• *3)
PCB1 output voltage Voltage
Vcc 12 – GND2 12 VDC
Vcc 05 – GND1 5 VDC
Vcc 12 – GND1 12 VDC
Vcc 15 – GND1 15 VDC
Vcc 24 – GND1 24 VDC
Vcc 12T– GND1 12 VDC
• *4) The rotary switch (RSW2) is not available depending on the indoor unit model.