Mitsubishi Electric S Series Manual page 104

OUTDOOR UNIT
2-4. Outdoor unit failure mode table
SUZ-KA25VA SUZ-KA35VA
NOTE 1. The location of LED is illustrated at the right figure.
2. LED lights up during normal operation.
LED indication Abnormal point
(Outdoor P.C. board) (Failure mode/protection)
— None (Normal)
Outdoor power system
—
1-time flash every Discharge temperature
2.5 seconds thermistor
Defrost thermistor
3-time flash
Fin temperature thermistor
2.5 seconds OFF
4-time flash P.C. board temperature
2.5 seconds OFF thermistor
2-time flash Ambient temperature
2.5 seconds OFF thermistor
11-time flash
Overcurrent
2.5 seconds OFF
12-time flash Compressor synchronous
2.5 seconds OFF abnormality (Compressor start-
up failure protection)
Discharge temperature
—
High pressure
—
7-time flash Fin temperature/P.C. board
2.5 seconds OFF temperature
Outdoor fan motor
—
5-time flash
Nonvolatile memory data
2.5 seconds OFF
Discharge temperature
—
8-time flash
DC voltage
2.5 seconds OFF
9-time flash Each phase current of
2.5 seconds OFF compressor
10-time flash Overcurrent Compressor open-
2.5 seconds OFF phase
14-time flash Stop valve (Closed valve)
2.5 seconds OFF
The blinking frequency shows the number of times the LED blinks after every 2.5-second OFF.
(Example) When the blinking frequency is "2".
ON
OFF
B-104
SUZ-KA50VA
Condition
Overcurrent protection stop is
continuously performed 3 times within
1 minute after the compressor gets
started.
Thermistor shorts or opens during
compressor running.
Large current flows into intelligent
power module.
Waveform of compressor current is
distorted.
Temperature of discharge temperature
thermistor exceeds 116°C, compressor
stops.
Compressor can restart if discharge
temperature thermistor reads 100°C or
less 3 minutes later.
Temperature indoor coil thermistor
exceeds 70°C in HEAT mode.
Temperature defrost thermistor
exceeds 70°C in COOL mode.
Temperature of fin temperature
thermistor on the inverter P.C. board
exceeds 75 ~ 80°C, or temperature of
P.C. board temperature thermistor on
the inverter P.C. board exceeds 70 ~
75°C.
Outdoor fan has stopped 3 times in a
row within 30 seconds after outdoor
fan start-up.
Nonvolatile memory data cannot be
read properly.
Temperature of discharge temperature
thermistor has been 50°C or less for 20
minutes.
DC voltage of inverter cannot be
detected normally.
Each phase current of compressor
cannot be detected normally.
Large current flows into intelligent
power module (IPM).
The open-phase operation of
compressor is detected.
The interphase short out occurs in the
output of the intelligent power module
(IPM).
The compressor winding shorts out.
Closed valve is detected by
compressor current.
2.5-second OFF
Inverter P.C. board (Parts side)
—
•Reconnect connectors.
•Check stop valve.
•Defective outdoor thermistors can be
identified by checking the blinking
pattern of LED.
•Reconnect compressor connector.
•Check stop valve.
•Reconnect compressor connector.
•Check refrigerant circuit and refrigerant
amount.
•Check refrigerant circuit and refrigerant
amount.
•Check stop valve.
•Check around outdoor unit.
•Check outdoor unit air passage.
•Check of outdoor fan motor.
•Check of inverter P.C. board.
•Replace the inverter P.C. board.
•Check of LEV.
•Check refrigerant circuit and refrigerant
amount.
•Check inverter.
•Check compressor.
•Reconnect compressor connector.
•Check stop valve
0.5-second ON
2.5-second OFF
S series
LED
blinking
Correspondence
—
0.5-second ON