Hitachi RAS-2-HVNP Service Manual page 255

8. Troubleshooting
Compressor
stops
immediately.
(Itc=1, 12)*
Restart operation.
Compressor
stops after
few minutes.
(Itc=1)
(Itc=21)*
Is the supply voltage
AC220/240V+10%?
Yes
Is voltage higher
than 170V during
operation?
Yes
Is voltage higher
than 170V at
any time?
Yes
Is the compressor
running current
as same as
operating current?
Yes
Is crankcase
heater ON?
Yes
N O T E
• *1) Perform the high voltage discharge work by referring to the item Procedure of checking other main parts,
before checking and replacing the inverter components.
• *2) Regarding replacing or checking method for inverter components, refer to item
other main parts.
• *3) Turn ON the No.1 switch of the dip switch DSW1 on PCB2 (inverter) when restarting with disconnecting the
terminals of the compressor. After troubleshooting, turn OFF the No.1 switch of the dip switch DSW1 on PCB2.
• When the alarm code "53" is indicated, the outdoor fan motor (DC motor) ensure that DC fan motor is checked
according to the item Procedure of checking other main parts.
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SMGB0079 rev.0 - 01/2013
Turn OFF power,
disconnect U, V, W
from compressor
terminals and restart.
Does the protecting
function activate? *3)
Yes It trips.
Is heat exchanger
clogged?
No
No
No
No
No
No
Is refrigerant
overcharged?
Is expansion valve of I.U.
open-locked in cooling operation?
Is expansion valve of O.U.
open-locked in heating operation?
Is the discharge
pressure high?
Normal
No
Check
the compressor.
Abnormal
Yes
* Refer to the item 1.2.8 (D)
"Cause Code of Inverter Stoppage" for details.
Yes
No
Yes
No
No
Yes
O.U.: Outdoor Unit
I.U.: Indoor Unit
Failure of Inverter PCB.
Replace it.
Check the compressor.
Replace it if faulty.
Remove clogging or
Replace heat exchanger.
Faulty Inverter PCB
Replace it.
Check the capacity
and wiring of
the power source.
Restart operation
after main switch ON.
Charge refrigerant
correctly.
Replace
expansion valve.
Check
the compressor.
Check stop valve
and expansion valve.
Check clogging of
the heat exchanger.
Check fan motor.
Procedure of checking
8