Hitachi RAS-(2-6)HVNP1(E), Service Manual

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8 Troubleshooting
211
SMGB0087 rev.0 - 12/2013
8
Phenomenon Cause Check item
Action
(Turn OFF the main switch)
The compressor does
not stop or start even
if the setting
temperature on the
LCD changes to *3)
Failure of air inlet
thermistor
Failure of thermistor
Check it by self-checking *2)
Replace or correctly connect
the wires if abnormal
operation exists
Disconnection of
thermistor
Abnormal operation of the remote control
switch cord
Failure of the indoor unit PCB
Check PCB by means of the
self-check mode *1)
Replace PCB if it failed
Incorrect optional setting
Check the setting condition
of “remote control thermo-
stat” by means of the op-
tional setting.
Setting and control:
“00”: Control by means of
the indoor thermistor for the
suction air.
“01”: Control by means of
the thermostat of the remote
control switch.
“02”: Control by means of
the average value of the
indoor thermistor for the suc-
tion air and the thermostat of
the remote control switch
If the thermostat of the re-
mote control switch is not
used, set at “00”
Incorrect Input/Output setting
Check setting condition of
“i1” and “i2” by Input/Output
setting.
* Setting and Control:
“01”: Room thermostat
(Cooling)
“02”: Room thermostat
(Heating)
In case that room thermostat
is not used, set for input sig-
nal actually used. If no signal
is used, set at “00”
Air flow volume “HH2”
is not indicated on the
remote control swith.
(Depending on I.U
model)
Incorrect Remote Control Switch Model
Check that Remote Control
Switch or Transition Wiring
for Remote Control Switch is
directly connected to Indoor
Unit(s) with “HH2” Air Flow
Volume function
Connect remote control
switch or transition wiring
for remote control switch to
indoor unit(s) with “HH2” air
flow volume function if neces-
sary
Indoor fan speed
does not change
Failure of the
discharge air
temperature
thermistor
Failure of the
thermistor
Check the thermistor by
means of the self-check
mode *2)
Replace or correctly connect
the wiring when it is
abnormal
Disconnected wire of
the thermistor
Failure of the remote control switch
Check it by means of the
self-check mode *1)
Replace if it failed
Failure of PCB for the indoor unit Replace if PCB fails
No defrost operation
mode is available
during the heating
process or the defrost
operation continues
Failure of thermistor
for outdoor evaporat-
ing temperature dur-
ing heating
Failure of thermistor
Replace or correctly connect when it is abnormal
Disconnected wire of
thermistor
Failure of 4-way valve
Disconnected 4-way
valve coil
Measure the resistance of
coil
Replace the 4-way valve
Incorrect activation of
4-way valve
Enforced power supply
Disconnected control wires between indoor
unit and outdoor unit
Check the connectors Correctly connect the wiring
Failure of the outdoor
units of PCB
Disconnected wiring
to PCB
Check the connectors Correctly connect the wiring
Failure of PCB
Check PCB by means of the
self-check mode *1)
Replace PCB when the
check mode is not available
Failure of the indoor
unit of PCB
Disconnected wiring
to PCB
Check the connectors Correctly connect the wiring
Failure of the PCB
Check PCB by means of the
self-check mode *1)
Replace if PCB fails
The LED and the LCD
on the remote control
switch remain ON
Failure of PCB in the indoor unit or the
remote control switch