Hitachi SAMURAI Series Service Manual page 145

4. Troubleshooting
Troubleshooting by alarm code
C1-28
Alarm code
Alarm stop reason
Suction pressure sensor (Ps) of compressor indicates an abnormal value.
PCB monitoring position
PCBd (I/O PCB) CN32PS (Suction pressure sensor (Ps))
N O T E
Refer pressure sensor characteristics chapter.
The connection and insertion of connector
CN32Ps on PCBd (I/O PCB) is correct
DC5V is being supplied between pin 1 and pin
3 of connector C32Ps on PCBd (I/O PCB)
Is the voltage between pin 2 and pin 3
of connector CN32Ps on PCBd (I/O PCB)
lower than DC0.5V or higher than DC4.5V when
discharge pressure sensor is connected?
There is clogging inside the connection pipe of
discharge pressure sensor
Replacement of discharge pressure
137
SMGB0082 rev.1 - 07/2015
Suction pressure sensor abnormality (CN32)
Yes
No
Yes
Yes
No
sensor
No
Revision of connections
Replace PCBd (I/O PCB)
No
Replace PCBd (I/O PCB)
Yes
Elimination of the factors
for clogging inside the
pipe
4