Hitachi RPI-0.8FSG1 Service Manual page 76

TROUBLESHOOTING
Alarm
Code
G "RUN" light flickers and "ALARM" is indicated on the remote control switch.
G 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 a suction pressure is lower than 0.02 MPa (0.2 kg/cm
12 minutes and its state occurs more than 3 times including 3 in one hour.
Is the amount of refrigerant correctly?
Is the outdoor stop valve open?
Is refrigerant leaking?
Is suction pressure sensor normal?
Are the electronic ex. valves fully
closed and locked?
Check if connections of electric wiring
and refrigerant piping between the indoor
and outdoor unit are wrong.
Phenomenon
Excessively
Low Suction
Pressure
(in Vacuum)
Internal
Thermostat for
Outdoor Fan
is Activated
in Heating
Operation
1-66
Activation to Protect System from Excessively Low Suction Pressure
(Protection from Vacuum Operation)
No
Yes
No
Yes
Yes
No
No
Yes
Yes
No
Check the indoor ex. valve during cooling
and the outdoor ex. valve during heating.
Cause
Shortage of Ref.
Closed Stop Valve
Abnormal Low or High
Pressure Sensor
Incorrect Connection
between Indoor Unit and
Outdoor Unit
Locked Ex. Valve
Closed Ex. Valve by
Disconnecting Td Thermistor
Faulty Outdoor Fan Motor
Fault
Faulty
Internal
Incorrect
Thermostat
Contact
Incorrect
Connection
Correctly charge refrigerant.
Open the stop valve.
Replace suction pressure sensor
if faulty.
Check connection of the connectors
and the circuit board. Replace the
electronic ex. valves if faulty.
NOTE:
In the case of H-LINK system, check the refrigerant
system setting of the outdoor PCB and indoor PCB.
Check Item
Check ref. charged
volume or check for
leakage.
Check stop valve.
Check connector
for PCB.
Check electrical
system and ref. cycle.
Check connector
for PCB.
Check Td thermistors
for compressors and
measure Td thermistor
resistance.
Measure coil resistance
and insulation resistance.
Check for conduction
after temperature of
outdoor fan motor is
decreased.
Measure resistance
by tester.
Check connection.
2
G) for over
Repair leaks.
Action
(Turn OFF Main Switch)
Repair leakage and
correctly charge.
Open stop valve.
Replace pressure
sensor if faulty.
Correctly connect
between indoor unit
and outdoor unit.
Repair or replace
connector of PCB or
ex. valve.
Repair or replace
Td thermistor.
Replace outdoor fan
motor if faulty.
Replace outdoor fan
motor.
Remove looseness
and replace connector.
Connect correctly.