Mitsubishi Electric SUZ-KA25VA Service Manual page 62

SUZ-KA50VA SUZ-KA60VA
Outdoor LED indication Abnormal point
(Failure mode)
LED1 LED2
Outdoor thermistors
Lighting
Once
Twice
3 times
4 times
9 times
5 times Outdoor control system
6 times Converter control
system
7 times
5 times
Goes out
6 times
Goes out
SUZ-KA71VA (Except for SUZ-KA50VAR2.TH)
Details of abnormal
Discharge temperature
When a short circuit is detected in the
thermistor thermistor during operation, or when an
open circuit is detected in the thermistor
after 10 minutes of compressor start-up.
Defrost thermistor When a short circuit is detected in the
thermistor during operation, or when an
open circuit is detected in the thermistor
after 5 minutes of compressor start-up.
Ambient temperature When a short or open circuit is detected
thermistor in the thermistor during operation.
Fin temperature thermistor
P.C. board temperature
thermistor
Outdoor heat exchanger When a short circuit is detected in the
temperature thermistor thermistor during operation, or when an
open circuit is detected in the thermistor
after 5 minutes (in cooling) and 10 minutes
(in heating) of compressor start-up.
When nonvolatile memory data cannot
EEPROM
be read properly, unit stops.
Communication error When the communication between
between P.C. boards
boards protection stop is continuously
performed twice.
Communication between Communication error occurs between
P.C. boards protection the electronic control P.C.board and
power board for more than 10 seconds.
Current sensor Current sensor protection stop is
continuously performed twice.
Current sensor protection When a short or open circuit is
detected in the current sensor during
compressor operating.
Zero cross detecting circuit The protection stop of the zero cross
detecting circuit is continuously
performed 10 times.
Zero cross detecting When zero cross signal cannot be
circuit protection detected while the compressor is
operating.
Converter protection When a failure is detected in the
operation of the converter during
operation.
When the bus-bar voltage exceeds
Bus-bar voltage protection (1)
400V or falls to 200V or below during
compressor operating.
Bus-bar voltage protection (2)
When the bus-bar voltage exceeds
Even if this protection
400V or falls to 50V or below during
stop is performed
compressor operating.
continuously 3 times,
it does not mean the
abnormality in outdoor
power system.
Detecting method
62
Check point
• Check the outdoor thermistors.
• Replace the outdoor electronic
control P.C. board.
• Check the outdoor thermistors.
• Replace the outdoor electronic
control P.C. board.
• 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.