Mitsubishi Electric SUZ-KA25VA Technical & Service Manual page 56

Abnormal point
Outdoor LED indication
LED1 LED2 (Failure mode)
Overcurrent protection
Once Goes out
Fin temperature/P.C.
3 times Goes out
board temperature
overheat
4 times Goes out
Refrigerant system
Lighting Lighting
High pressure
protection
Low discharge
temperature
Outdoor fan
Outdoor power
system
Details of abnormal
IPM protection When overcurrent is detected after
30 seconds of compressor start-up.
Lock protection When overcurrent is detected within 30
seconds after the compressor gets started.
Fin temperature overheat When the fin temperature exceeds 87:
protection during operation.
P.C.boad temperature When the P.C. board temperature exceeds
overheat protection 70: during operation.
Discharge temperature
When discharge temperature exceeds
overheat protection 116:.
HPS protection When high-pressure is detected with the
high-pressure switch (HPS) during operation.
High pressure protection
When the indoor coil thermistor (TH5)
(Overheat protection) exceeds 70: in HEAT mode.
When the outdoor heat exchanger thermistor
exceeds 70: in COOL mode.
Low discharge When the frequency of the compressor is
temperature protection kept 80Hz or more and discharge
temperature is kept under 39: for more
than 20 minutes.
Outdoor fan protection When outdoor fan has stopped within 30
seconds 3 times in a row after outdoor fan
start -up,unit stops.
Outdoor power system When IPM protection stop or lock
protection stop is continuously
performed 3 times within 1 minute after
the compressor get started, or when
converter protection stop or bus-bar
voltage protection stop is continuously
performed 3 times within 3 minutes after
start-up.
Detecting method
56
Check point
• Check the connection of the compressor
connecting wire.
• Check the inverter/ compressor.
• Check the stop valve.
• Check around outdoor unit.
• Check outdoor unit air passage.
• Check the outdoor fan motor.
• Check refrigerant circuit and refrigerant
amount.
• Check the LEV.
• Check the outdoor thermistors.
• Check refrigerant circuit and refrigerant
amount.
• Check the stop valve.
• Check refrigerant circuit and refrigerant
amount.
• Check the LEV.
• Check the outdoor fan motor.
• Reconnect compressor connector.
• Check the inverter/ compressor.
• Check the stop valve.
• Check the PAM module.