Hitachi RAS-(4-12)HNP(1)(E) - Overcurrent Protection Activation for RAS-(3-12)H(V)N(P;C)(1)(E)

8 Troubleshooting
261
SMGB0087 rev.0 - 12/2013
8
Alarm code
48
Overcurrent protection activation for RAS-(3-12)H(V)N(P/C)(1)(E)
Yes
Restart operation
after applying
current
Charge refrigerant
correctly
Restart expansion
valve
Check the
compessor
Is pressure
excessively high?
No
Yes
Check the stop
valves and
expansion valve
No
Restart operation.
Does it trip soon?
Yes
Check the
compressor
Check the power
source capacity
Replace the PCB2
(IPM or DIP IPM).
*1)
Is there any cause of
instantaneous voltage
decrease?
No
No
Yes
Yes, it trips
It trips
immediately
It trips after a
certain period
In case of 3N~400V/50Hz:
Is the power supply voltage 380V ±10% or 415V ±10%?
In case of 1~230V/50Hz:
Is the power supply voltage 230V ±10%?
Check the capacity
and wiring of the
power source
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?
Is refrigerant
charged excessively?
Yes
Yes
Yes
Yes
Yes
No
Is lock of indoor expansion
valve opened at cooling
operation?
Is lock of outdoor expansion valve
opened at heating operation
Yes
Check for clogging
at heat exchanger
Check the fan
No
No
No
No
Turn OFF power and
disconnect U, V, W from
compressor terminals.
Turn ON number 1 of DSW1 on
PCB2 (IPM or DIP IPM) and
restart.
Does it trip? *1)
In case of 3N~400V/50Hz:
Is the power supply voltage 323V during operation?
In case of 1~230V/50Hz:
Is the power supply voltage 187V during operation?
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.