Hitachi FSG Series Service Manual page 60

1
TROUBLESHOOTING
52
Alarm Code
45
Activation to Protect System from Excessively High Discharge Pressure
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, and the
unit No. and alarm code are indicated on the display of the outdoor unit PCB.
‘
This alarm code is indicated when the compressor is operated under the conditions higher than 2.7 MPa
(27 kg/cm²G) of discharge pressure ( in case of frequency 30Hz, Pd is higher than 2.5 MPa (25 kg/cm²G)
and its occurrence is more than 3 times including 3 in one hour).
Is there a leakage of the solenoid
valves SVA?
No
Is the outdoor unit stop valve closed?
No
Is the high-pressure sensor good?
Yes
Are ex. valves fully closed and locked?
No
Are electric wiring and refrigerant
piping between the indoor and
outdoor unit incorrectly connected?
No
Check if indoor or outdoor intake air
temperature is too high.
Phenomenon
Leakage of Solenoid Valve
Abnormal High Pressure
Excessively
High Discharge
Pressure
Excessively High Indoor Unit
and Outdoor Unit Inlet Air Temp.
Incorrect Connection between
Indoor Unit and Outdoor Unit
Locked Ex. Valve with Fully
Yes
Yes
No
Yes
Check the outdoor electronic expansion valve
during cooling and the indoor electronic expansion
valve during heating.
Yes
Cause
SVA (Outdoor Unit)
Closed Stop Valve
Sensor
Closed Opening
Replace the solenoid valve SVA if
Check connection of the circuit board
connector. Replace the high-pressure
Check the circuit board and connection
of the circuit board connector. Replace
the electronic expansion valves if faulty.
No In the case of H-LINK connection,
check the refrigeration cycle setting on
the PCB of outdoor unit and indoor unit.
Check Item
Check outlet temp. of
solenoid valve, SVA.
Check stop valve.
Check connectors for
PCB.
Check thermistor for indoor
unit and outdoor unit inlet air
temp.
. Check electrical system and
ref. cycle.
Check connector for PCB.
faulty.
Open the stop valve.
sensor if faulty.
Correctly connect it..
Action
(Turn OFF main switch)
Check connection. Replace
solenoid valve SVA if faulty.
Open stop valve.
Replace pressure sensor if
faulty.
Replace thermistor if
faulty.
Correctly Connect.
Repair connector for PCB or
ex. valve. Replace it if faulty.