Hitachi RAS-2-HVNP Service Manual page 253

8. Troubleshooting
53
Alarm code
• The RUN LED flickers and "ALARM" is displayed on the remote control switch.
• The unit number, the alarm code and the unit code are alternately displayed on the set temperature section. The unit
number and the alarm code are displayed on the display of the outdoor unit PCB.
- IPM or Dip IPM and PCB2 have detecting function of abnormality. This alarm is indicated when the transistor mod-
ule detect the abnormality 7 times in 30 minutes including 7. Retry operation is performed up to the occurrence of
6 times.
Conditions:
• The abnormal current such as short circuited, grounded or the overcurrent occurs at the transistor module.
• The temperature at transistor module increases abnormally.
• The control voltage decreases.
• The angle difference between the shaft in compressor and the shaft in the control program exceeds +60deg.
Compressor
stops
immediately.
(Itc=1, 12)*
Restart operation.
Compressor
stops after
few minutes.
(Itc=21)*
* Refer to the item 1.2.8 (D)
"Cause Code of Inverter Stoppage" for details.
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.
239
SMGB0079 rev.0 - 01/2013
Activation of transistor module (RAS-3HVNPE / RAS-(4-6)H(V)NCE)
Turn OFF power,
disconnect U, V, W
No
from compressor
terminals and restart.
Does the protecting
function activate? *3)
Yes
Yes
Is heat exchanger of
clogged?
No
Normal
Check Failure of Inverter PCB.
the compressor. Replace it.
Abnormal
Check the compressor.
Replace it if faulty.
Remove clogging or
replace heat exchanger.
Faulty Inverter PCB
Replace it.
Check the compressor.
Check pressure and
refrigerant cycle.
Procedure of checking
Is high pressure
increased?
Check clogging for
heat exchanger.
Check fan motor.
8