Mitsubishi Electric MUZ-EF25VE, Руководство по обслуживанию

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37
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
17-time fl ash
2.5 seconds OFF Outdoor refrigerant
system abnormality
A closed valve and air trapped in the refrigerant circuit are
detected based on the temperature sensed by the indoor and
outdoor thermistors and the current of the compressor.
• Check for a gas leak in a
connecting piping etc.
• Check the stop valve.
• Refer to 11-5. “Check of outdoor
refrigerant circuit”.
9
'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 intelligent power module.
• Reconnect connector of compressor.
• Refer to 11-5. "How to check in-
verter/compressor".
• Check the stop valve.
10
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
the refrigerant amount.
• Refer to 11-5. "Check of LEV".
11
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 the around outdoor unit.
• Check the outdoor unit air passage.
• Refer to 11-5. "Check of outdoor
fan motor".
12
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
the refrigerant amount.
• Check the stop valve.
13
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".
14
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.
15
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".
16
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".
17
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 the if indoor fi lters are
clogged.
• Check the if refrigerant is short.
• Check the if indoor/outdoor unit air
circulation is short cycled.
18
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.
19
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
the refrigerant amount.
• Refer to 11-5. "Check of LEV".
• Refer to 11-5. "Check of outdoor
thermistors".
20
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.
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
OBH590G