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TROUBLESHOOTING
“RUN” light flickers and “ALARM” is indicated on the remote control switch.
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 code is indicated when the pressure sensor voltage decreases lower than 0.1V or
increases higher than 4.9V during running.
Alarm
Code
Abnormality of Low Pressure Sensor
(Outdoor Unit)
Cause
Check Item
Action
(Turn OFF Main Switch)
Phenomenon
Faulty Low
Pressure Sensor
Check output voltage
is correct.
Replace pressure
sensor if faulty.
Fault
Indicated
Pressure Value
is Excessively
High or Low
Check for clogging
of check joint.
Replace check joint.
Malfunction of Pressure
Sensor due to Faulty
Check Joint
Check connections.
Repair wiring and
connections.
Incorrect Connection
Replace PCB and
check operation.
Replace PCB if faulty.
Faulty PCB
Is the connection CN8
of the outdoor unit
PCB1 mated loose?
Is 5 VDC applied across
#1 and #3 of the connector
CN8 of the outdoor circuit
board PCB1?
Is voltage under 0.1 VDC
or over 4.9 VDC across
#2 and #3 of the connector
CN8 of the outdoor circuit
board PCB1?
Yes
Yes
Is the Check Joint
clogged?
Abnormality with Low
Pressure Sensor.
Connect correctly.
Faulty PCB1
Yes
No
Faulty PCB1
No
No
No
Replace the check joint.
Yes