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