Hitachi RAS-2-HVNP Service Manual page 248

8. Troubleshooting
48
Alarm code
Yes
Restart operation.
Does it trip soon?
It trips
immediately
It trips after a
certain period
In case of 380-415V/50Hz
Is the power supply voltage 380V ±10% or 415V ±10% ?
In case of 220~240V/50Hz:
Is the power supply voltage 230V ±10%?
In case of 380-415V/50Hz:
Is the power supply voltage 323V during operation?
In case of 220~240V/50Hz:
Is the power supply voltage 187V during operation?
Is it 170V (single phase) or 340V (3 phases) or more
during operation when other devices are operating?
Is the compressor running current the same as rated
current?
Is current applying to
crankcase heater?
N O T E
*1) Perform the high voltage discharge work by referring to section Procedure of checking other main parts before
checking and replacing the inverter PCB.
234
SMGB0079 rev.0 - 01/2013
Overcurrent protection activation for RAS-(3-12)H(V)N(P/C)(E)
Turn OFF power and
disconnect U, V, W from
compressor terminals.
Turn ON #1 of DSW1 on PCB2
(IPM or dipIPM) and restart.
Does it trip? *1)
Yes, it
trips
Yes
Yes
Yes
Yes
No
Yes
Is refrigerant charged
Is lock of indoor expansion valve
opened at cooling operation?
Is lock of outdoor expansion valve
opened at heating operation?
Is pressure excessively
No
Is there any cause of
instantaneous voltage
decrease?
Yes
No
No
Check the capacity and
wiring of the power source.
No
No
Yes
excessively?
No
Yes
No
Yes
high?
No
Check the
compressor.
Check the power
source capacity.
Replace the PCB2
(IPM or dipIPM). *1)
Restart operation after
applying current.
Charge refrigerant
correctly.
Restart expansion
valve.
Check the compressor.
Check the stop valves
and expansion valve.
Check for clogging at
heat exchanger.
Check the fan.