Mitsubishi Electric MUZ-FH25VE, Руководство по обслуживанию

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30
11-3. TROUBLESHOOTING CHECK TABLE
No. Symptom LED indication Abnormal point/
Condition
Condition Remedy
1
Outdoor unit
does not op-
erate.
1-time
fl
ash every
2.5 seconds
Outdoor power sys-
tem
Overcurrent protection cut-out operates 3 consecutive times
within 1 minute after the compressor gets started.
Reconnect connector of compres-
sor.
Refer to 11-5. "How to check in-
verter/compressor".
Check stop valve.
•
•
•
2
Outdoor thermistors Discharge temperature thermistor,
fi
n temperature thermistor,
defrost thermistor, P.C. board temperature thermistor, outdoor
heat exchanger temperature thermistor or ambient tempera-
ture thermistor shorts or opens during compressor running.
Refer to 11-5. "Check of outdoor
thermistors".
•
3
Outdoor control sys-
tem
Nonvolatile memory data cannot be read properly.
(POWER lamp of the indoor unit lights up or
fl
ashes 7-time.)
Replace inverter P.C. board. •
4
6-time
fl
ash
2.5 seconds OFF
Serial signal The communication fails between the indoor and outdoor unit
for 3 minutes.
Check connection between the in-
verter P.C. board and the relay P.C.
board. (
FH50
)
Refer to 11-5. "How to check
miswiring and serial signal error.
•
•
5
11-time
fl
ash
2.5 seconds OFF
Stop valve/
Closed valve
Closed valve is detected by compressor current. Check stop valve. •
6
14-time
fl
ash
2.5 seconds OFF
Outdoor unit
(Other abnormality)
Outdoor unit is defective. Refer to 11-2.2. "Flow chart of the
detailed outdoor unit failure mode
recall function".
•
7
'Outdoor unit
stops and
restarts 3
minutes later'
is repeated.
2-time
fl
ash
2.5 seconds OFF
Overcurrent protec-
tion
Large current
fl
ows into power module (IC700) (
FH25/35
)/
IGBT module (IC700) (
FH50
).
Reconnect connector of compressor.
Refer to 11-5. "How to check in-
verter/compressor".
Check stop valve.
•
•
•
8
3-time
fl
ash
2.5 seconds OFF
Discharge tempera-
ture overheat pro-
tection
Temperature of discharge temperature thermistor exceeds
116°C, compressor stops. Compressor can restart if discharge
temperature thermistor reads 100°C or less 3 minutes later.
Check refrigerant circuit and refrig-
erant amount.
Refer to 11-5. "Check of LEV".
•
•
9
4-time
fl
ash
2.5 seconds OFF
Fin temperature
/P.C. board tem-
perature thermistor
overheat protection
Temperature of
fi
n temperature thermistor on the heat sink ex-
ceeds 75 ~ 86°C (
FH25/35
)/75 ~ 80°C (
FH50
) or temperature
of P.C. board temperature thermistor on the inverter P.C.board
exceeds 72 ~ 85°C (
FH25/35
)/70 ~ 75°C (
FH50
).
Check around outdoor unit.
Check outdoor unit air passage.
Refer to 11-5. "Check of outdoor
fan motor".
•
•
•
10
5-time
fl
ash
2.5 seconds OFF
High pressure pro-
tection
Indoor coil thermistor exceeds 70°C in HEAT mode. Defrost
thermistor exceeds 70°C in COOL mode.
Check refrigerant circuit and refrig-
erant amount.
Check stop valve.
•
•
11
8-time
fl
ash
2.5 seconds OFF
Compressor syn-
chronous abnormal-
ity
The waveform of compressor current is distorted. Reconnect connector of compressor.
Refer to 11-5. "How to check in-
verter/compressor".
•
•
12
10-time
fl
ash
2.5 seconds OFF
Outdoor fan motor Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan start-up.
Refer to 11-5. "Check of outdoor
fan motor.
Refer to 11-5. "Check of inverter
P.C. board.
•
•
13
12-time
fl
ash
2.5 seconds OFF
Each phase current
of compressor
Each phase current of compressor cannot be detected nor-
mally.
Refer to 11-5. "How to check in-
verter/compressor".
•
14
13-time
fl
ash
2.5 seconds OFF
Bus-bar voltage
(DC)
Bus-bar voltage of inverter cannot be detected normally. It occurs with following case.
Instantaneous power voltage drop.
(Short time power failure) (
FH50
)
Refer to 11-5. "Check of power
supply". (
FH50
)
Refer to 11-5. "How to check in-
verter/compressor".
•
•
•
15
Outdoor unit
operates.
1-time
fl
ash
2.5 seconds OFF
Frequency drop by
current protection
FH25/35
When the input current exceeds approximately
10A (
FH25
)/10.5A (
FH35
), compressor frequency
lowers.
The unit is normal, but check the
following.
Check if indoor
fi
lters are clogged.
Check if refrigerant is short.
Check if indoor/outdoor unit air
circulation is short cycled.
•
•
•
FH50
Current from power outlet is nearing breaker ca-
pacity.
16
3-time
fl
ash
2.5 seconds OFF
Frequency drop by
high pressure pro-
tection
Temperature of indoor coil thermistor exceeds 55°C in HEAT
mode, compressor frequency lowers.
Frequency drop by
defrosting in COOL
mode
Indoor coil thermistor reads 8°C or less in COOL mode, com-
pressor frequency lowers.
17
4-time
fl
ash
2.5 seconds OFF
Frequency drop by
discharge tempera-
ture protection
Temperature of discharge temperature thermistor exceeds
111°C, compressor frequency lowers.
Check refrigerant circuit and refrig-
erant amount.
Refer to 11-5. "Check of LEV".
Refer to 11-5. "Check of outdoor
thermistors".
•
•
•
18
MUZ-FH25/35
5-time
fl
ash
2.5 seconds OFF
Outside temperature
thermistor protec-
tion
When the outside temperature thermistor shorts or opens,
protective operation without that thermistor is performed.
Refer to 11-5. Check of outdoor
thermistors.
•
OBH624A