Mitsubishi Heavy Industries SRK25GZ-L1 Handbook page 1075

(a) Diagnosis by the power supply reset
When any error occurs, reset the power supply as described below to see if it is the result of accidental noise, etc.
Check at the indoor unit side.
Error
Are the return air
temperature and Center/
Remote displayed on the
remote controller?
NO
Power switch OFF
Power supply line error
Errors due to external noise, etc.
Error code may be displayed or the error may not be displayed normally even if the controller is normal because of external noise
source (1) or joined or parallel arrangement of power cables and signal wires. It is because the wire of remote controller, wired
remote controller signal wires for multiple units or the network signal wires may be influenced by external noises whitch are
judged as signals by the microcomputer whitch reacts mistakenly.
When there is any noise source, it is necessary to the shield wire for the remote controller and signal wires.
Note (1) High frequency medical machine, rectifier motor application device, thyristor, broadcast transmission tower, power
transmission line, power line of electric train, automatic door motor, elevator (voltage drop), wireless telephone, high
voltage power distribution line, computer, personal compouter and their cables.
There do not necessarily always cause problems but they can be a source of electrical noise.
YES
Is any error
code display?
YES
Check the error
code displayed
ON/OFF
switch OFF
Does the error
code disappear?
YES
Turn off the wiring breaker (power
supply) and back on again 1min. later. (Power supply reset)
ON/OFF
switch OFF
Does start operation
with display of cool-
ing degree: Hi, ther-
mostat: 23°C?
YES
Does the error repeat
YES
Check of error code
NO
NO
Microcomputer
out of control
NO
Power supply line error
NO
Cause is accidental (noise, etc.)
and the unit is normal.
FDC-HKXR
See page 1077
1073