Hitachi FSG Series Service Manual page 50

1
TROUBLESHOOTING
42
Alarm Code
Abnormality of Thermistor for Discharge Gas Temperature on the Top of
23
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, or the
unit No. and alarm code are indicated on the display of the outdoor unit PCB. (*1)
If abnormality with the thermistor is found, check all the thermistors as shown below.
‘
This alarm code is indicated when the thermistor is short-circuited (less than 0.9 kW) or cut (greater than
2,350 kW) during running.
Is the setting of DSW2 on
PCB1 right?
Yes
Are thermistors, THM8, THM9,
THM12 and THM13 connected
to THM8(TD1) , THM9(TD2),
THM12(TD3) and THM13(TD4)?
Yes
Is resistance of THM8, THM9,
THM12 and THM13 same with
characteristic in below figure?
Yes
Faulty PCB1
Resistance of
Thermistor
(KW)
Ambient temperature
Characteristics Of Thermistor
Phenomenon
Faulty
Discharge Gas
Thermistor
Faulty PCB
Incorrect Setting of DSW2 on PCB1
Compressor Chamber
No
Set DSW2 on PCB1
correctly.
No
Connect them.
No
Faulty Thermistor.
.
Cause
Fault
Incorrect Connection
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
Faulty TD1
Faulty TD2
Faulty TD3
Faulty TD4
(*1) Indication on the display
of the outdoor unit PCB
Check Item
Check resistance.
Check wiring to PCB.
Replace PCB and Check
operation
Check setting of DSW2 on
PCB1
Model
Thermistor
position (a)
8 10 16 20
Inverter
fix compressor
2 2 3 4
Action
(Turn OFF main switch)
Replace thermistor if
faulty.
Repair wiring and
connections.
Replace PCB if faulty
Correctly set DSW2 on
PCB1