Mitsubishi Electric MXZ-2C30VA Service Manual page 91

MXZ-6C
Upper or
left lamp of
OPERATION Abnormal point
INDICATOR (Failure mode/protection)
lamp (Indoor
unit)
11-time fl ash Communication error between
P.C. boards
Current sensor
Zero cross detecting circuit
Bus-bar voltage
12-time fl ash Compressor (open phase)
14-time fl ash Power module
15-time fl ash LEV and drain pump
11-3. INSTRUCTION OF TROUBLESHOOTING
• Check the indoor unit by referring to the indoor unit service manual, and confirm whether there is any problem in the indoor
unit. Then, check the outdoor unit by referring to this page.
Operation start
Check the outdoor unit
LED indicator.
Both LED 1
and LED 2
are OFF.
Refer to 11-6.
"Check of power supply".
• Indoor unit • COOL or
serial signal HEAT
error operation only
Refer to 11-6. Refer to 11-6.
"How to "Check of
check R.V. coil".
miswiring and
serial signal
error".
OBH584G
LED indication
(Outdoor P.C. board)
Lighted 6 times
Lighted 7 times
5 times Not
lighted
6 times Not
lighted
10 times Not
lighted
7 times Not
lighted
Lighted Lighted
Both LED 1 and
LED 2 are lighting.
• When cooling, heat
exchanger of
non-operating indoor
unit frosts.
•When heating, non-
operating indoor unit
gets warm.
Refer to 11-6.
"Check of LEV".
Condition
Communication error occurs between the
control P.C. board (MXZ-6C120VA)/outdoor
control P.C. board (MXZ-6C122VA) and
power board (MXZ-6C120VA)/outdoor
power P.C. board (MXZ-6C122VA) for more
than 10 seconds.
The communication between boards
protection cut-out operates 2 consecutive
times.
After the operation starts, a short or open
circuit is detected in the current sensor
when the compressor is not operating.
Current sensor has been short or open
circuited for 120 seconds.
Zero cross signal cannot be detected while
the compressor is operating.
The protection cut-out of the zero cross de-
tecting circuit operates 3 consecutive times.
The bus-bar voltage exceeds
400 V or falls to 300 V or below during
compressor operating.
Waveform of compressor current is dis-
torted.
The overcurrent is detected when the fre-
quency of the compressor is 1 Hz or less.
The indoor unit detects an abnormality in
the LEV and drain pump.
• When cooling, • When heating,
dew drops in the room does not get
non-operating
warm.
indoor unit. Refer to 11-6.
Check of "How to check of
mispiping inverter/compressor".
Check mispiping,
shortage of capacity
91
Indoor/
outdoor
unit failure
Remedy
function
• Check the connecting wire
between the control P.C. board
(MXZ-6C120VA)/outdoor con-
trol P.C. board (MXZ-6C122VA)
and the power board (MXZ-
6C120VA)/outdoor power P.C.
board (MXZ-6C122VA).
• Replace the power board
(MXZ-6C120VA)/outdoor pow-
er P.C. board (MXZ-6C122VA).
• Check the connecting wire
between control P.C. board
(MXZ-6C120VA)/outdoor con-
trol P.C. board (MXZ-6C122VA)
and the power board (MXZ-
6C120VA)/outdoor power P.C.
board (MXZ-6C122VA).
• Check the voltage of power
supply.
• Replace the power board
(MXZ-6C120VA)/outdoor pow-
er P.C. board (MXZ-6C122VA).
• Check the connection of the
compressor connecting wire.
• Refer to 11-6. " How to check
inverter/compressor.
• Refer to 11-6. " How to check
inverter/compressor.
• Refer to 11-6. "Check of
LEV".
• Check the drain pump of the
indoor unit.
LED 1 or LED 2
has blinked.
Refer to 11-4.
"Troubleshooting check table".
• When cooling,
room does not
cool.
Refer to 11-6.
"How to check
of inverter/
compressor".
mode
recall
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