Mitsubishi Electric MUZ-SF25VE, Руководство по обслуживанию

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32
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 the 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.
(The left lamp of OPERATION INDICATOR 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.
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 the 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
16-time
fl
ash
2.5 seconds OFF
4-way valve/
Pipe temperature
The 4-way valve does not work properly.
The indoor coil thermistor detects an abnormal temperature.
Refer to 11-5. "Check of R.V.
coil".
Replace inverter P.C. board.
•
•
8
'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. Reconnect connector of compressor.
Refer to 11-5. "How to check in-
verter/compressor".
Check the stop valve.
•
•
•
9
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 the refrigerant circuit and
refrigerant amount.
Refer to 11-5. "Check of LEV".
•
•
10
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
exceeds 75 ~ 86°C or temperature of P.C. board temperature
thermistor on the inverter P.C.board exceeds 72 ~ 85°C.
Check around outdoor unit.
Check outdoor unit air passage.
Refer to 11-5. "Check of outdoor
fan motor".
•
•
•
11
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 the refrigerant circuit and
refrigerant amount.
Check the stop valve.
•
•
12
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".
•
•
13
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.
•
•
14
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".
•
15
13-time
fl
ash
2.5 seconds OFF
DC voltage DC voltage of inverter cannot be detected normally. Refer to 11-5. "How to check in-
verter/compressor".
•
16 Outdoor unit
operates.
1-time
fl
ash
2.5 seconds OFF
Frequency drop by
current protection
When the input current exceeds approximately 7A(
EF25
)/
8A(
EF35
)/9A(
EF42
)/12A(
EF50
), compressor frequency lowers.
The unit is normal, but check the
following.
Check if the indoor
fi
lters are
clogged.
Check if the refrigerant is short.
Check if the indoor/outdoor unit air
circulation is short cycled.
•
•
•
17
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.
18
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 the refrigerant circuit and
refrigerant amount.
Refer to 11-5. "Check of LEV".
Refer to 11-5. "Check of outdoor
thermistors".
•
•
•
19
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.
•
20
Outdoor unit
operates.
7-time
fl
ash
2.5 seconds OFF
Low discharge tem-
perature protection
Temperature of discharge temperature thermistor has been
50°C or less for 20 minutes.
Refer to 11-5. "Check of LEV".
Check the refrigerant circuit and
the refrigerant amount.
•
•
21
8-time
fl
ash
2.5 seconds OFF
PAM protection
PAM: Pulse Ampli-
tude Modulation
The overcurrent
fl
ows into PFC (Power factor correction :
IC820) or the bus-bar voltage reaches 394 V or more, PAM
stops and restarts.
This is not malfunction. PAM pro-
tection will be activated in the fol-
lowing cases:
1 Instantaneous power voltage
drop. (Short time power failure)
2 When the power supply voltage
is high.
22
9-time
fl
ash
2.5 seconds OFF
Inverter check mode The connector of compressor is disconnected, inverter check
mode starts.
Check if the connector of the com-
pressor is correctly connected.
Refer to 11-5. "How to check
inverter/compressor".
•
NOTE:
1. The location of LED is illustrated at the right
fi
gure. Refer to 11-6.1.
2. LED is lighted during normal operation.
The
fl
ashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the
fl
ashing frequency is “2”.
ON
OFF
2.5-second OFF
2.5-second OFF
0.5-second ON
0.5-second ON
LED
Flashing →
Inverter P.C. board
OBH629A