Hitachi RAS-10HRNM, Service Manual, Page: 275 / 482

Alarm code
53
Protection activation of IPM or DipIPM and PCB2 ( RAS-(3-6)HVRNM(1)E) and RAS-
(8-12)HRNM) for IVX Series
• 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 module
detect the abnormality 7 times in 30 minutes including 7. Retry operation is performed up to the occurrence of 6
times.
Conditions:
• Abnormal current to the transistor module such as
– Short circuited or grounded
or
– Abnormal temperature of the IPM or Dip IPMand PCB2
or
– Control voltage decrease
Turn off power, disconnect
U, V, W from compressor
terminals and restart.
Does the protecting function
activate? *3)
No
Check the IPM or Dip
IPM. *1) *2)
Check the compressor.
(If there is a short-circuit
between phase lines, replace
the compressor.)
Yes
Yes
Faulty
No
No
Check the PCB2
Good
Replace IPM or Dip IPM
Replace IPM and PCB2
Coat the silicon grease to all
the touched face between
the IPM and the radiated fin
fully. *4)
Is the silicon grease coated all
over between the IPM or Dip IPM
and the radiated fin?
Good
Yes
Is the heat exchanger
of outdoor unit clogged?
Remove clogging.
Replace the PCB2
Faulty
N O T E
• *1) Perform the high voltage discharge work by referring to the item Procedure of checking other main parts
for ES Series , see on page 312 before checking and replacing the inverter components.
• *2) Regarding replacing or checking method for inverter components, refer to item Procedure of checking other
main parts for ES Series , see on page 312.
• *3) Turn ON the No.1 switch of the dip switch DSW1 on PCB2 when restarting with disconnecting the terminals
of the compressor. After troubleshooting, turn OFF the No.1 switch of the dip switch DSW1 on PCB2.
• *4) Use the silicon grease provided as accessory (Service parts No. P22760).
• 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 for ES Series , see on page 312.
8 Troubleshooting
267
SMGB0060 rev. 1- 12/2010
8