Hitachi EV-1.5N1, Service Manual

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8. Troubleshooting
234
SMGB0079 rev.0 - 01/2013
Alarm code
48
Overcurrent protection activation for RAS-(3-12)H(V)N(P/C)(E)
Restart operation.
Does it trip soon?
Yes
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)
No
No
Is there any cause of
instantaneous voltage
decrease?
No
Check the
compressor.
Check the power
source capacity.
Replace the PCB2
(IPM or dipIPM). *1)
Yes
Yes, it
trips
It trips
immediately
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%?
Yes
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?
Yes
Is it 170V (single phase) or 340V (3 phases) or more
during operation when other devices are operating?
Yes
Is the compressor running current the same as rated
current?
Yes
Check the capacity and
wiring of the power source.
Check the fan.
Check for clogging at
heat exchanger.
Check the stop valves
and expansion valve.
Check the compressor.
Restart expansion
valve.
Charge refrigerant
correctly.
Restart operation after
applying current.
Is current applying to
crankcase heater?
No
No
No
No
Is refrigerant charged
excessively?
Yes
Yes
No
Is lock of indoor expansion valve
opened at cooling operation?
Is lock of outdoor expansion valve
opened at heating operation?
Yes
Is pressure excessively
high?
No
Yes
It trips after a
certain period
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.