Hitachi RAS-10HRNM, Service Manual, Page: 278 / 482

Alarm code
53
Protection activation of IPM or PCB2 for ES 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 PCB1.
– 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:
• Short Circuited or Grounded
• Abnormal Temperature of the IPM and PCB2
• Control Voltage Decrease
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 the 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 alarm code “53” is indicated, the outdoor fan motor (DC motor) may be faulty. Check to ensure that DC
fan motor is checked according to the item
Procedure of checking other main parts for ES Series , see on page
312.
If DC motor is damaged, normal inverter IPM will be damaged
8 Troubleshooting
270
SMGB0060 rev. 1- 12/2010