Hitachi FSG Series Service Manual page 39

Alarm Code
08
Excessively High Discharge Gas Temperature at the Top of Compressor Chamber
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.
‘
This alarm is indicated when the following conditions occurs three times within one hour:
(1) The temperature of the thermistor on the top of the compressor is maintained higher than
132 °C for 10 minutes, or
(2) The temperature of the thermistor on the top of the compressor is maintained higher than
140 °C for 5 seconds.
Is the thermistor on top of
compressor good?
Yes
Is the thermistor installed
correctly on the compressor?
Yes
Is it at cooling or heating
mode when the alarm has
occurred?
Cooling
Cooloing Operation
Yes
Check the outdoor unit PCB if
the compressor discharge gas
temperature is over 132 °C
Yes
Is the opening of all the
operating indoor unit ex.
valve 100%?
Yes
Is the amount of refrigerant
correct?
Yes
Is gas leaking?
Yes
Repair leaks of gas.
Recharge refrigerant.
No
Faulty Thermistor
See page 1-42 for the thermistor resist.
No
Install it correctly.
Heat
Heating Operation
Check the outdoor unit PCB to
see if the compressor discharge
gas temperature is over 132 °C.
No
No
Remove sudden changes
of indoor load (short path,
etc.) or short path of air
between outdoor unit.
No
Charge correct refrigerant
volume. Refer to Chapter
12 of TC.
No
Check the ex. valve.
TROUBLESHOOTING
Position of the Thermistor
RAS-[HP]FSG/FS3
Thermis-
Display 5
tor ref.
ód1
THM8
ód2
THM9
ód3
THM12
ód4
THM13
No. of compressors
1
No
Yes
Is the opening of the outdoor
unit ex. valve 100%?
Yes
Are the connector (CN10 and
CN11 of PCB1) of the outdoor
unit heat exchanger's expansion
valve connected properly?
Yes
1
31
Model
Thermistor
position (a)
8 10 16 20
Inverter
fix compressor
2 2 3 4
Remove sudden changes
of load like short path of
No
outgoing air to the air
intake of the outdoor unit,
or the cause of frequent
thermo- ON/OFF.
No
Plug the connector CN10
and CN11 of PCB1
properly.