Hitachi Utopia RPI-2.5HRG Service Manual page 14

(1.1.6 Abnormalities of Devices)
Phenomenon
Failure of
Discharge
Air Temp.
Thermistor
Indoor Fan
Speed is
Not Changed
Failure of
Thermistor
for Outdoor
Evaporating
Temp. during
Heating
Failure of
4-Way Valve
No Defrosting
Operation Mode
is Available
Disconnected Control Wires
during Heating
between Indoor Unit and
Operation or
Outdoor Unit
Defrosting
Operation is
Continued
Failure of
Outdoor Unit
PCB
Failure of
Indoor Unit
PCB
Light and
LCD Indication
Failure of PCB in Indoor Unit
on Remote
or Remote Control Switch
Control Switch
are Kept ON
*1): Refer to Item 1.3.1 to 1.3.2.
*2): Refer to Item 1.2.3.
Cause
Failure of
Thermistor
Disconnected
Wire of
Thermistor
Failure of Remote
Control Switch
Failure of PCB for
Indoor Unit
Failure of AC Chopper
for Indoor Unit
Failure of
Thermistor
Disconnected
Wire of
Thermistor
Disconnected
4-Way Valve
Coil
Incorrect
Activation of
4-Way Valve
Disconnected
Wires to PCB
Failure of
PCB
Disconnected
Wires to PCB
Failure of
PCB
Check Item
Check thermistor by
self-checking *2).
Check it by
self-checking *1).
Check the indoor unit
stoppage when the
remote control switch
is switched OFF.
Measure resistance
of coil.
Enforced power supply.
Check connectors.
Check connectors.
Check connectors.
Check PCB by
self-checking *1).
TROUBLESHOOTING
Action
(Turn OFF Main Switch)
Replace or correctly
connect wiring when
it is abnormal.
Replace if failed.
Replace if PCB
is failed.
Replace if AC
Chopper is failed.
Replace of correctly
connect when it is
abnormal.
Replace 4-Way valve.
Correctly connect
wiring.
Correctly connect
wiring.
Replace it when check
mode is not available.
Correctly connect
wiring.
Replace if PCB is failed.
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