Mitsubishi Electric MSZ-G09SV Service Manual page 71

OUTDOOR UNIT
MUZ-G09SV - MUZ-G12SV -
E1
MUZ-G09SV - MUZ-G12SV -
E2
NOTE 1. The location of LED is illustrated at the right figure.
2. LED lights up during normal operation.
Refer to page 92.
No.
Symptom LED indication
1-time flash every
Outdoor unit
2.5 seconds
1
does not
operate
2
NOTE:
For abnormality
location, refer to
3
'Indoor
troubleshooting
check table' on
4
page 69.
2-time flash
'Outdoor unit
5
2.5 seconds OFF
stops and
restarts 3
3-time flash
minutes later'
2.5 seconds OFF
6 is repeated
4-time flash
2.5 seconds OFF
7
5-time flash
2.5 seconds OFF
8
Outdoor unit
1-time flash
9
operates (at
2.5 seconds OFF
low
3-time flash
frequency)
2.5 seconds OFF
10
4-time flash
2.5 seconds OFF
11
Outdoor unit 5-time flash
operates 2.5 seconds OFF
12
6-time flash
13
2.5 seconds OFF
7-time flash
2.5 seconds OFF
14
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is "2".
ON
OFF
E1
E2
Abnormal point
Serial signal When serial signal stops from indoor unit for 60 seconds,
compressor stops and then restarts 3 minutes later.
Outdoor power
When compressor has stopped by over current protection
system
within 1 minute after compressor start-up 3 times in a row,
compressor stops and then restarts 3 minutes later.
Outdoor When discharge temperature thermistor or fin temperature
thermistors
thermistor shorts or opens during compressor running,
compressor stops and restarts 3 minutes later.
When nonvolatile memory date cannot be read properly,
Outdoor control
system compressor stops and restarts 3 minutes later.
Over current When 19A(MUZ-G09SV)/ 29A(MUZ-G12SV) current flows into
protection power transistor, compressor stops and restarts 3 minutes later.
Discharge
When discharge temperature thermistor exceeds 116:,
temperature
compressor stops and restarts 3 minutes later.
overheat
(Compressor restarts when discharge temperature thermistor
protection reads 100: or below.)
When temperature at heat sink exceeds 78:(MUZ-G09SV)/
Fin temperature
80:(MUZ-G12SV) or outdoor electronic control P.C. board
thermistor overheat
exceeds 68:(MUZ-G09SV)/ 78:(MUZ-G12SV), compressor
protection
stops and restarts 3 minutes later.
High pressure When indoor coil thermistor exceeds 75:, compressor stops
protection and restarts 3 minutes later.
Frequency drop by When current from power outlet exceeds 8A(MUZ-G09SV)/
current protection 9A(MUZ-G12SV), compressor frequency lowers.
Frequency drop by When indoor coil thermistor exceeds 55: in HEAT mode,
high pressure compressor frequency lowers.
protection
Frequency drop by When indoor coil thermistor reads 8: or below in COOL mode,
defrosting in COOL compressor frequency lowers.
mode
Frequency drop by, When discharge temperature thermistor exceeds 111:,
discharge compressor frequency lowers.
temperature
protection.
When defrost thermistor short or open.
Outdoor
w In this case, compressor continues running.
thermistors.
Defrost thermistor.
Power factor
When power factor of compressor is not detected.
w In this case, compressor continues running.
detection
Low discharge
When discharge temperature has been 50: or below for 20
temperature
minutes.
protection
2.5-second OFF
Detection method
0.5-second ON
2.5-second OFF
71
<Outdoor electronic control P.C. board>
Transistor Hybrid
module IC
transformer
Checkpoint
· Refer to Q "How to check mis-
wiring and serial signal error" on
page 83.
· Refer to M "Check of power supply"
on page 81.
· Refer to A "How to check inverter/
compressor" on page 76.
· Refer to J "Check of outdoor
thermistors" on page 79.
Replace outdoor electronic control
P.C. board.
Refer to A "How to check inverter/
compressor" on page 76.
· Check refrigerant circuit and
refrigerant amount.
· Refer to J "Check of outdoor
thermistors" on page 79.
· Check around outdoor unit.
· Check outdoor unit air passage.
· Check refrigerant circuit and
refrigerant amount.
· Check stop valve.
The unit is normal, but check the
following.
· Check if indoor filters are clogged
· Check if refrigerant is short.
· Check if indoor/outdoor unit air
outlets are short cycled.
Refer to J "Check of outdoor
thermistors" on page 79.
Check compressor wiring.
· Refer to P "Check of LEV" on
page 82.
· Check refrigerant circuit and
refrigerant amount.
0.5-second ON
LED
flashing