Hitachi FS3 Series, Service Manual

Page: 66 / 240

1
58
TROUBLESHOOTING
Alarm Code
53
Protection Activation of Transistor Module
n
”RUN” light flickers and ”ALARM” is indicated on the remote control switch.
n
The unit No., alarm code and the unit code is alternately indicated on the set temperature section, and the
unit No. and alarm code are indicated on the display of the outdoor unit PCB.
‘
Transistor module have detecting function of abnormality. This alarm is indicated when the transistor
module detect the abnormality 3 times in 30 minutes including 3. Retry operation is performed up to the
occurrence of 2 times.
Conditions: Abnormal Current to the Transistor Module such as Short Circuited or Grounded or Abnormal
Temperature of the Transistor Module 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 compressor. (If there
is a short-circuit between phase
lines, replace the compressor.)
Yes
Yes
Check the transistor
module. 1*)
Faulty
Check the inverter
circuit board. 2*)
Good
Replace the transistor module
Good
Faulty
Replace the transistor module
and inverter circuit board.
Is the heat exchanger of
outdoor unit clogged?
Yes
Remove clogging.
No
Replace the inverter circuit
board.
1*): Regarding replacing or checking method for the transistor module, refer to page 1-91.
2*): Regarding the checking of inverter components, refer to page 1-90 regarding electrical discharge.
3*): Turn ON #1 of the dip switch DSW1 on PCB3 when restarting with disconnecting the terminals of the compressor.
After troubleshooting, turn OFF #1 of the dip switch DSW1 on PCB3.