Abnormal Transmission Between The Remote Control Switch And The Indoor Unit; Abnormal Operation Of The Devices - Hitachi RASC-4HNPE Service Manual

10 Troubleshooting
Initial troubleshooting

10.1.3 Abnormal transmission between the remote control switch and the indoor unit

• RUN LED on the remote control switch:
Flickering every 2 seconds.
Phenomenon
Disconnection or insufficient contacting of the remote control
cable
Failure of the remote control switch
Failure of PCB
(in the indoor unit and the
remote control switch)
?
N O T E
*1): Refer to section "Self-checking procedure of the remote control
*2): Refer to section "Self-checking procedure of PCB by means of the remote control

10.1.4 Abnormal operation of the devices

Phenomenon
RUN LED is ON and the LCD
is indicated. However, the
system does not operate.
(For example, the indoor
fan, the RASC fan or the
compressor does not
operate)
188 SMGB0091 rev.2 - 11/2015
Cause
Disconnected wire to PCB
Failure of PCB
Cause
Disconnected
Failure of the
coil
indoor unit fan
motor
Burnt-out coil
Disconnected
Failure of the
coil
RASC unit fan
motor
Burnt-out coil
Failure of the
magnetic switch Insufficient
for the RASC contacting
unit fan motor
Failure of the compressor motor
Failure of the compressor
Failure of the
Insufficient
magnetic switch
contacting
for compressor
Disconnec ted
wiring to PCB
Failure of one of
PCBs
Failure of PCB
Check item
Check the cable and the
connections
Check the remote control switch
using the self-check mode *1)
Check the connectors
Check PCB using the
self-check mode *2)
switch".
switch".
Check item
Measure the coil resistance
using the tester
Measure the insulation
resistance
Measure the coil resistance
using the tester
Measure the insulation
resistance
Measure the voltage between
the contacting parts
Measure the resistance
between two wires
Check for an abnormal sound
from the compressor
Check that the magnetic
switch activates correctly or
not
Check the connections
Check PCB using the self-
check mode *2)
Action
(Turn OFF the main switch)
Repair the cable or connect the
cable
Replace the remote control
switch if the remote control
switch is faulty
Correctly connect the wires
Replace PCB if it failed
Action
(Turn OFF the main switch)
Replace the indoor unit fan
motor
Replace the RASC unit fan
motor
Replace PCB for the RASC
unit
Replace the compressor
Replace the magnetic switch
Correctly connect the wiring
Replace PCB if it failed