Mitsubishi Electric SEZ-KD VA Series, Service Manual

Page: 90 / 301

90
11-time flash
15-time flash
• Check the connecting
wire between the outdoor
control P.C. board and
the power P.C. board.
• Replace the power P.C.
board.
• Check the connecting
wire between the control
P.C. board, the noise
filter P.C. board and
the power P.C. board.
• Check the voltage of the
power supply.
• Replace the power P.C.
board.
• Check the voltage of the
power supply.
• Replace the outdoor
control P.C. board.
• Refer to 11-6. "Check
of LEV".
• Check the drain pump of
the indoor unit.
The communication between boards
protection cut-out operates 2
consecutive times.
Communication error occurs
between the electronic control P.C.
board and power board for more
than 10 seconds.
Current sensor protection cut-out
operates 2 consecutive times.
A short or open circuit is detected in
the current sensor during compressor
operating.
The protection cut-out of the zero cross
detecting circuit operates 10
consecutive times.
Zero cross signal cannot be detected
while the compressor is operating.
A failure is detected in the operation
of the converter during operation.
The bus-bar voltage exceeds 400 V or
falls to 200 V or below during
compressor operating.
The bus-bar voltage exceeds
400 V
(MXZ-3D54/3D68/4D72VA
MXZ-3D54VA2)
430 V (MXZ-4D83/5D102VA)
or falls to 50V or below during
compressor operating.
Communication error
between P.C. boards
Current sensor
Zero cross detecting circuit
Converter
Bus-bar voltage
(1)
Bus-bar voltage
(2)
Even if this protection stop is
performed continuously three
times, it does not mean the
abnormality in outdoor power
system.
LEV and drain pump
Lighted 6 times
Lighted 7 times
5 times Not
lighted
5 times
Not
lighted
5 times
6 times
Not
lighted
Not
lighted
The indoor unit detects an abnormality
in the LEV and drain pump.
Lighted Lighted
Abnormal point
(Failure mode/protection)
Condition Remedy
Indoor/outdoor
unit failure mode
recall function
LED indication
(Outdoor P.C. board)
LED 1 LED 2
Upper or left lamp of
OPERATION INDICATOR
lamp (Indoor unit)
NOTE : Blinking patterns of this mode differ from the ones of "Troubleshooting check table" (11-4).
Operation start
Check the outdoor unit
LED indicator.
Refer to 11-6.
"Check of power supply".
• Indoor unit
serial signal
error
Refer to 11-6.
"How to
check
miswiring
and serial
signal error".
• COOL or HEAT
operation only
Refer to 11-6.
"Check of
R.V. coil"
• When heating, room
does not get warm.
• When cooling,
room does not cool.
Refer to 11-6.
"How to check of
inverter/compressor".
Check mispiping,
shortage of capacity
• 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".
• When cooling, dew
drops in the non-
operating indoor
unit.
Check of mispiping
Refer to 11-4.
"Troubleshooting check table".
Both LED 1 and
LED 2 are lighting.
LED 1 or LED 2
has blinked.
Both LED 1
and LED 2
are OFF.
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.
OBH626E