Mitsubishi Electric MSZ-G09SV Service Manual page 72

OUTDOOR UNIT
MUZ-G20SV -
E1
LED 1 (red)
Lighting
NOTE: When both LED lamps are not lighting, check if the power is supplied to the unit. Refer to "U" on page 85.
Indication
Abnormal point
LED 1 LED 2
(red) (Yellow)
Lighting 2-time Outdoor power system
Lighting 7-time Outdoor control system
DC voltage sensing cir-
Lighting 9-time
cuit
Indication
Abnormal point
LED 1 LED 2
(red) (Yellow)
Discharge temperature
Lighting 3-time
thermistor
Fin temperature ther-
Lighting 4-times
mistor
P.C. board temperature
Lighting 5-times
thermistor
Not
2-time Over current protection
lighting
Not Discharge temperature
3-time
lighting overheat protection
Not Fin temperature over-
4-time
lighting heat protection
P.C. board temperature
Not
4-time
overheat protection
lighting
LED 2 (yellow)
Lighting
Symptom: Outdoor unit does not operate.
Detecting method
When the compressor operation has been interrupted by overcurrent
protection continuously three times within 1 minute after start-up.
When the nonvolatile memory data cannot be read properly on the out-
door electronic control P.C. board.
When DC voltage sensing circuit detects 57V or below or 395V or above
Symptom: Outdoor unit repeats to stop and restart in 3 minutes
Detecting method
When a short or open circuit occurs in the discharge temperature ther-
mistor during compressor running.
When a short or open circuit occurs in the fin temperature thermistor
during compressor running.
When a short or open circuit occurs in the P.C. board temperature ther-
mistor during compressor running.
When over current is applied to the power module.
When the discharge temperature thermistor detects 116: or above.
(Protection will be released at 100: or below.)
When the fin temperature thermistor detects 91: or above.
When the P.C. board temperature thermistor detects 79: or above.
Error mode
Normal
72
Refer to page 93.
Check points
• Check the inverter / compressor.
Refer to "Y" on page 88.
• Replace the outdoor electronic control
P.C. board.
• Replace the outdoor electronic control
P.C. board.
Check points
• Check the characteristic of the discharge
temperature thermistor.
Refer to "Z" on page 89.
• Check the connector. (CN663)
• Check the characteristic of the fin temper-
ature thermistor.
Refer to "Z" on page 89.
• Check the connector. (CN664)
• Replace the outdoor electronic control
P.C. board.
• Check the inverter / compressor.
Refer to "Y" on page 88.
• Check the amount of gas.
• Check the indoor / outdoor air flow for
short cycle.
• Check the indoor unit air filter for clogging.
• Check the amount of gas and the refriger-
ant cycle.
• Check the outdoor unit air passage.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.
Refer to " " on page 89.
AA
• Check the power module.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.
Refer to " AA " on page 89.
• Replace the outdoor electronic control
P.C. board.