Hitachi RAS-H(V)RNME-AF Service Manual page 371

12 Troubleshooting
21
Alarm code 2nd ambient temperature sensor (THM
• The alarm code is displayed on the LCD User interface.
• The alarm code is displayed on the seven segments of the indoor unit PCB.
• This alarm code is displayed when the sensor is abnormality when 2ND ambient sensor option is enabled.
Is ATW-2OS-01
connected to (intake)
terminals 32(+) &33 (-) of
TB2?
(+) – TB2-32(+)
ATW-2OS-01
(-) – TB2--33(-)
Is resistance
inside ATW-2OS-01
between 92.16kΩ and
119.40kΩ?
Yes
Is the current of
ATW-2OS-01 output
between 4-20 mA?
Yes
Is the temperature
of THMamb2 between
50ºC and -30ºC?
Yes
Faulty PCB1
361
SMGB0070 rev. 1 - 08/2011
No
TB2
Yes
No
No
No
) Thermistor Abnormality
AMB2
Connect it
Faulty device
(Change ATW-2OS-01)
Yes
Is the
current 0mA?
No
Check correct
position of
THMamb2 and
correct it
Repair harness
Check Harness connection
between TB2-32/33 and
PCB Connection (check
Electrical wiring diagram)
Datas: Resistance value
220Ω Power supply to
ATW-2OS-01 (+) 12Vcc
Is all correctly?
Yes
Faulty device
(Change ATW-2OS-01)
12