Hitachi FS3 Series, Service Manual

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1
42
TROUBLESHOOTING
Alarm Code
23
Abnormality of Thermistor for Discharge Gas Temperature on 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, 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 k
W
) or cut (greater than
2,350 k
W
) during running.
Is the setting of DSW2 on
PCB1 right?
No
Set DSW2 on PCB1
correctly.
Yes
Are thermistors, THM8, THM9,
THM12 and THM13 connected
to THM8(TD1) , THM9(TD2),
THM12(TD3) and THM13(TD4)?
No
Connect them.
Yes
Is resistance of THM8, THM9,
THM12 and THM13 same with
characteristic in below figure?
No
Faulty Thermistor.
Yes
Faulty PCB1 .
Resistance of
Thermistor
(K
W
)
Faulty TD1
Faulty TD2
Faulty TD3
Faulty TD4
Ambient temperature
Characteristics Of Thermistor
(*1) Indication on the display
of the outdoor unit PCB
Phenomenon Cause Check Item
Action
(Turn OFF main switch)
Fault Check resistance.
Replace thermistor if
faulty.
Faulty
Discharge Gas
Thermistor
Incorrect Connection Check wiring to PCB.
Repair wiring and
connections.
Faulty PCB
Replace PCB and Check
operation
Replace PCB if faulty
Incorrect Setting of DSW2 on PCB1
Check setting of DSW2 on
PCB1
Correctly set DSW2 on
PCB1
Position of the Thermistor
Model
RAS-[HP]FSG/FS3
Thermistor
position (a)
Thermis-
tor ref.
Display 5 8 10 16 20
THM8
ód1
Inverter
THM9
ód2
fix compressor
THM12
ód3
THM13
ód4
No. of compressors 1 2 2 3 4