27
ON
OFF
2.5-second OFF
2.5-second OFF
The flashing frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the flashing frequency is “2”.
Abnormal point/ Condition
Overcurrent protection stop is continuously performed 3 times
within 1 minute after the compressor gets started, or failure of
restart of compressor has repeated 24 times.
Discharge temperature thermistor, fin temperature thermistor,
defrost thermistor, P.C. board temperature thermistor or
ambient temperature thermistor shorts or opens during
compressor running.
Nonvolatile memory data cannot be read properly.
(POWER lamp of the indoor unit lights up or flashes 7-time.)
Large current flows into intelligent power module, or
compressor repeats after 15 seconds when overcurrent
protection occures within 10 seconds after compressor starts.
(Repeated 24 times at Maximum)
Temperature of discharge temperature thermistor exceeds
116
:
, compressor stops. Compressor can restart if discharge
temperature thermistor reads 100
:
or less 3 minutes later.
Temperature of fin temperature thermistor on the heat sink
exceeds 75
:
~ 80
:
or temperature of P.C. board
temperature thermistor on the inverter P.C.board exceeds 70
:
~ 75
:
.
Indoor coil thermistor exceeds 70
:
in HEAT mode.
Defrost thermistor exceeds 70
:
in COOL mode.
Current from power outlet reaches the protection current, and
compressor frequency lowers.
Temperature of indoor coil thermistor exceeds 55
:
in HEAT
mode, compressor frequency lowers.
Indoor coil thermistor reads 8
:
or less in COOL mode,
compressor frequency lowers.
Temperature of discharge temperature thermistor exceeds 111
:
, compressor frequency lowers.
Temperature of discharge temperature thermistor has been 50
:
or less for 20 minutes.
No.
1
2
3
7
8
9
10
15
16
17
18
19
Symptom
LED indication
Condition
Correspondence
Outdoor unit
does not
operate.
'Outdoor unit
stops and
restarts 3
minutes later'
is repeated.
Outdoor unit
operates.
Outdoor unit
operates.
1-time flash every
2.5 seconds
2-time flash
2.5 seconds OFF
3-time flash
2.5 seconds OFF
4-time flash
2.5 seconds OFF
5-time flash
2.5 seconds OFF
1-time flash
2.5 seconds OFF
3-time flash
2.5 seconds OFF
4-time flash
2.5 seconds OFF
7-time flash
2.5 seconds OFF
Outdoor power
system
Outdoor
thermistors
Outdoor control
system
Overcurrent
protection
Discharge
temperature
overheat
protection
Fin temperature
/P.C. board
temperature
thermistor
overheat protection
High pressure
protection
Frequency drop by
current protection
Frequency drop by
high pressure
protection
Frequency drop by
defrosting in COOL
mode
Frequency drop by
discharge
temperature
protection
Low discharge
temperature
protection
· Reconnect connector of compressor.
· Refer to 11-5.
A
"How to check
inverter/ compressor".
· Check stop valve.
· Refer to 11-5.
G
"Check of outdoor
thermistors".
· Reconnect connector of compressor.
· Refer to 11-5.
A
"How to check
inverter/compressor".
· Check stop valve.
Replace inverter P.C. board.
· Check refrigerant circuit and
refrigerant amount.
· Refer to 11-5.
K
"Check of LEV".
· Check around outdoor unit.
· Check outdoor unit air passage.
· Refer to 11-5.
I
"Check of outdoor
fan motor".
· 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
circulation is short cycled.
· Refer to 11-5.
K
"Check of LEV".
· Check refrigerant circuit and
refrigerant amount.
Inverter P.C. board (Parts side)
LED
Flashing
Refer to 11-5.
M
"How to check
miswiring and serial signal error.
The communication fails between the indoor and outdoor unit
for 3 minutes.
Serial signal
8-time flash
2.5 seconds OFF
Compressor
synchronous
abnormality
The waveform of compressor current is distorted.
· Reconnect connector of compressor.
· Refer to 11-5.
A
"How to check
inverter/compressor".
8-time flash
2.5 seconds OFF
PAM protection
PAM:
Pulse
Amplitude
Modulation
The overcurrent flows into IGBT(Insulated Gate Bipolar
transistor : TR821) or when the bus-bar voltage reaches 320 V
or more, PAM stops and restarts.
This is not malfunction.
PAM protection will be activated in
the following cases;
1
Instantaneous power voltage drop
(Short time power failure)
2
When the power supply voltage is
high.
9-time flash
2.5 seconds OFF
Inverter check
mode
The connector of compressor is disconnected, inverter check
mode starts.
Check if the connector of the
compressor is correctly connected.
Refer to 11-5.
A
"How to check
inverter/ compressor".
4
11
20
10-time flash
2.5 seconds OFF
Outdoor fan motor
6-time flash
2.5 seconds OFF
· Check stop valve.
Closed valve is detected by compressor current.
Stop valve/
Closed valve
5
11-time flash
2.5 seconds OFF
Outdoor fan has stopped 3 times in a row within 30 seconds
after outdoor fan start-up.
· Refer to 11-5.
I
"Check of outdoor
fan motor.
· Refer to 11-5.
L
"Check of inverter
P.C. board.
12
13
14
12-time flash
2.5 seconds OFF
Each phase
current of
compressor
Each phase current of compressor cannot be detected
normally
· Refer to 11-5.
A
"How to check
inverter/compressor".
13-time flash
2.5 seconds OFF
DC voltage
DC voltage of inverter cannot be detected normally.
· Refer to 11-5.
A
"How to check
inverter/compressor".
· Check refrigerant circuit and
refrigerant amount.
· Refer to 11-5.
K
"Check of LEV".
· Refer to 11-5.
G
"Check of
outdoor thermistors".
Refer to 11-2.2. "Flow chart of the
detailed outdoor unit failure mode
recall function".
Outdoor unit is defective.
Outdoor unit
(Other abnormality)
6
14-time flash
2.5 seconds OFF
0.5-second ON
0.5-second ON
11-3. Troubleshooting check table
NOTE: 1. The location of LED is illustrated at the right figure. Refer to 11-6.1.
2. LED is lighted during normal operation.
OBH489--1.qxp 07.8.9 4:27 PM Page 27
Summary of Contents for MUZ-FD25VA
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