Mitsubishi Electric MSZ-G09SV-E1 Service Manual page 46

1. Troubleshooting check table
MSZ-G09SV -
E1
MSZ-G09SV -
E2
flashing
Operation
Indicator
· Flashing of the operation indicator lamp (on the left-hand side) indicates possible abnormalities.
· The operation indicator lamp (on the left-hand side) is lighted during normal operation.
No.
Symptom Operation indicator lamp
Outdoor unit repeated flashes
does not every 0.5 seconds
operate
1
1-time flash
w2
2.5 seconds OFF
2-time flash
2.5 seconds OFF
w3
3-time flash
w4
2.5 seconds OFF
5-time flash
2.5 seconds OFF
5
6-time flash
2.5 seconds OFF
6
7-time flash
2.5 seconds OFF
7
w When the indoor unit has started operation and the above detection method has detected an abnormality (the first detection
after the power ON), the electronic control P.C. board turns OFF the 52C and the indoor fan motor with the operation indica-
tor lamp lighting.
When the 52C and the indoor fan motor are turned ON again 3 minutes later and the same abnormality is detected (a sec-
ond detection of the above abnormality after the power ON), the control P.C. board turns OFF the 52C and the indoor fan
motor with the operation indicator lamp flashing.
However, the first detection is cleared in case the power is turned OFF after the first detection.
(Indoor unit troubleshooting check table)
MSZ-G12SV -
E1
MSZ-G12SV -
E2
Abnormal point
Mis-Wiring
Serial signal
Indoor coil
thermistor
Auxiliary indoor
coil thermistor
Room
temperature
thermistor
Indoor fan motor
Outdoor power
system
Outdoor
thermistors
Outdoor control
system
Detection method
When indoor electronic control P.C. board does not
receive serial signals for 4 to 5 seconds with
OPERATION/ STOP(ON/ OFF) button of remote
controller ON and 52C relay ON for the first time.
NOTE: In case of serial signal error, mis-wiring
indication will appear by turning power off
and then turning it back on.
When indoor electronic control P.C. board does not
receive serial signals from outdoor unit for 4 to 5
seconds,
Indoor electronic control P.C. board constantly
detects resistance every 8 seconds.
When thermistor shorts or opens.
When rotational frequency feedback signal is not
emit during 12-second indoor fan operation.
When compressor has stopped due to over current
protection or start-up failure protection 3 times in a
row within 1 minute after start-up.
<Thermistor short>
Thermistors are abnormal when they short after
compressor start-up.
<Thermistor open>
Thermistors are abnormal when they open after
compressor start-up.
However, discharge temperature thermistor is
abnormal when open circuit is detected more than
10 minutes after compressor start-up.
When nonvolatile memory data cannot be read properly
on outdoor control P.C. board, outdoor unit stops and
restarts 3 minutes later.
46
Checkpoint
Refer to 'Checking
serial signal error' on
page 48.
Refer to the
characteristics of
indoor coil thermistor,
auxiliary indoor coil
thermistor, and room
temperature thermistor
on page 58.
Refer to G "Check of
indoor fan motor" on
page 53.
Refer to A "How to
check inverter/
compressor" on page
51.
· Shortage of
refrigerant
· Outdoor electronic
control P.C. board
Refer to J "Check
of outdoor
thermistors" on
page 54.
Replace outdoor
electronic control P.C.
board.