Mitsubishi Electric MUZ-GA50VA Service Manual page 29

Indoor operation Abnormal point
indicator lamp (Failure mode)
OFF Normal
11-time flash Converter
Outdoor LED indication
Details of abnormal point
LED1
-
-
Communication error Lighting 6 times When the communication between
between P.C. boards
Communication between P.C. Lighting 6 times Communication error occurs
boards protection
Current sensor Lighting 7 times Current sensor protection stop is
Current sensor protection Lighting 7 times When a short or open circuit is
Zero cross detecting circuit 5 times
Zero cross detecting circuit 5 times
protection
Converter protection 5 times
Bus-bar voltage 5 times
protection (1)
Bus-bar voltage 6 times
protection (2)
wEven if this protection stop is
performed continuously three
times, it does not mean the
abnormality in outdoor power
system.
Detecting method
LED2
-
boards protection stop is
continuously performed twice.
between the electronic control P.C.
board and power board for more
than 10 seconds.
continuously performed twice.
detected in the current sensor
during compressor operating.
Goes The protection stop of the zero
out cross detecting circuit is
continuously performed 10 times.
Goes When zero cross signal cannot be
out detected while the compressor is
operating.
When a failure is detected in the
Goes
operation of the converter during
out
operation.
When the bus-bar voltage exceeds
Goes
400V or falls to 200V or below
out
during compressor operating.
When the bus-bar voltage exceeds
Goes
out 400V or falls to 50V or below during
compressor operating.
29
Check point
-
• 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.
Indoor/outdoor
failure mode
recall function
-