Mitsubishi Electric SUZ-KA25VA Technical & Service Manual page 55

SUZ-KA50VA.TH SUZ-KA60VA.TH SUZ-KA71VA.TH
SUZ-KA50VA .TH SUZ-KA60VA
1
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
.TH SUZ-KA71VA
1
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
thermistor detected 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 boards
between P.C. boards protection stop is continuously
performed twice.
Communication between P.C. Communication error occurs between the
boards protection 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 circuit
When zero cross signal cannot be
protection detected while the compressor is
operating.
Converter protection When a failure is detected in the
operation of the converter during
operation.
Bus-bar voltage protection (1) When the bus-bar voltage exceeds 400V
or falls to 200V or below during
compressor operating.
Bus-bar voltage protection (2) When the bus-bar voltage exceeds
wEven if this protection stop is
400V or falls to 50V or below during
performed continuously 3 compressor operating.
times, it does not mean the
abnormality in outdoor power
system.
55
.TH
1
Detecting method
• Check the outdoor thermistors.
• Replace the outdoor electronic
• Check the outdoor thermistors.
• Replace the outdoor electronic
• Check the connecting wire between
outdoor electronic control P.C. board and
power board.
• Replace the power board.
• Check the connecting wire among
• Replace the power board.
Check point
control P.C. board.
control P.C. board.
electronic control P.C. board, noise
filter P.C. board and power board.