Mitsubishi Electric MXZ-2A20NA-1 Service Manual page 42

The left lamp of
Abnormal point
OPERATION INDICATOR
(Failure mode / protection)
lamp(Indoor unit)
Communication error
11-time flash
between P.C. boards
Current sensor
Zero cross detecting circuit
Converter
Bus-bar voltage
(1)
Bus-bar voltage
(2)
wEven if this protection stop is
performed continuously three
times, it does not mean the
abnormality in outdoor power
system.
15-time flash LEV for drain
NOTE : Blinking patterns of this mode differ from the ones of Troubleshooting check table (11-4.).
11-3. Instruction of troubleshooting
• Check the indoor unit with referring to the indoor unit service manual, and confirm that there is any problem in the indoor
unit.
Then, check the outdoor unit with referring to this page.
Operation start
Check the outdoor unit
LED indicator.
OFF
Refer to 11-6.
A "Check of power supply".
• Indoor unit • COOL or
serial signal HEAT
error operation only
Refer to 11-6. Refer to 11-6.
B "How to C "Check of
check R.V. coil".
mis-wiring and
serial signal
error".
LED indication
(Outdoor P.C. board)
LED 1 LED 2
Communication error occurs
Lighting 6 times
between the electronic control P.C.
board and power board for more
than 10 seconds.
When the communication between
boards protection stop is
continuously performed twice.
Lighting 7 times
When a short or open circuit is
detected in the current sensor
during compressor operating.
Current sensor protection stop is
continuously performed twice.
5 times Goes
When zero cross signal cannot be
out
detected while the compressor is
operating.
The protection stop of the zero
cross detecting circuit is
continuously performed 10 times.
5 times Goes
When a failure is detected in the
operation of the converter during
out
operation.
5 times
Goes
When the bus-bar voltage exceeds
out 400V or falls to 200V or below
during compressor operating.
6 times
Goes
When the bus-bar voltage exceeds
out
400V or falls to 50V or below during
compressor operating.
Lighting Lighting
When the indoor unit detects any
abnormal in the LEV for drain.
Both LED 1 and
LED 2 lighting
• When cooling, heat
exchanger of
non-operating indoor
unit frosts.
•When heating, non-
operating indoor unit
gets warm.
Refer to 11-6.
D "Check of LEV".
Condition
• When cooling, • When heating,
dew drops in the room does not get
non-operating warm.
indoor unit. Refer to 11-6.E
Check of mis- "How to check
piping inverter/ compressor".
Check mis-piping,
shortage of capacity.
42
Indoor/outdoor
Correspondence
unit failure mode
recall function
• Check the connecting
wire between outdoor
electronic control
P.C. board and power
board.
• Replace the power
board.
• Check the connecting
wire among electronic
control P.C. board,
noise filter P.C. board
and power board.
• Replace the power
board.
• Refer to 11-6.D "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 is not
cool.
Refer to 11-6.E
"How to check
inverter/
compressor".