Mitsubishi Electric MXZ-A14WV Service Manual page 55

MXZ-A26WV -
E1
MXZ-A32WV -
E1
LED 1 (Red)
Lighting
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
Lighting Once Indoor unit and LEV
Lighting Twice Outdoor power system
Lighting 7 times Outdoor control system
Indication
Abnormal point
LED 1 LED 2
(Red) (Yellow)
3 times Discharge temperature
Lighting
thermistor
Fin temperature
thermistor
Lighting 4 times
P.C. board temperature
thermistor
Evaporation temperature
Lighting 5 times
thermistor
Outdoor heat exchanger
Lighting 5 times
temperature thermistor
Lighting Current sensor
6 times
Gas pipe temperature A
thermistor
Gas pipe temperature B
thermistor
Lighting 10 times
Gas pipe temperature C
thermistor
Gas pipe temperature D
thermistor
Communication error
Lighting 11 times
between P.C. boards
Lighting 12 times Zero cross signal error
Twice Goes out Overcurrent protection
3 times Goes out Discharge temperature
overheat protection
Fin temperature
4 times Goes out
overheat protection
LED 2 (Yellow)
Lighting
Symptom: Outdoor unit does not operate.
Detecting method
When the drain abnormality is detected in the indoor unit and the indoor
unit coil temperature is too low, or when any abnormality is detected in
the components of indoor unit.
When the compressor operation has been interrupted by over current
protection continuously three times within 1 minute after start-up, or
when power factor control module protection or DC control protection is
activated three times within 3 minutes after the compressor get started.
When the nonvolatile memory data cannot be read properly on the
outdoor electronic control P.C. board.
Symptom: It is repeated that outdoor unit stops and restarts 3 minutes later.
Detecting method
When a short or open circuit occurs in the discharge temperature
thermistor during compressor operating.
When a short or open circuit occurs in the fin temperature thermistor
during compressor operating.
When a short or open circuit occurs in the P.C. board temperature
thermistor during compressor operating.
When a short or open circuit occurs in the evaporation temperature
thermistor during compressor operating.
When outdoor heat exchanger temperature thermistor is short or open
while compressor is operating.
When the output from compressor current sensor becomes 25A or
more while the compressor is operating.
When a short or open circuit occurs in the gas pipe temperature A
thermistor during compressor operating.
When a short or open circuit occurs in the gas pipe temperature B
thermistor during compressor operating.
When a short or open circuit occurs in the gas pipe temperature C
thermistor during compressor operating.
When a short or open circuit occurs in the gas pipe temperature D
thermistor during compressor operating.
When the communication failure between the outdoor electronic control
P.C. board and power board occurs twice consecutively.
When zero cross signal cannot be detected while the compressor is
operating.
When overcurrent 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 87: or above.
Error mode
Normal
55
Check points
• Check the abnormality indication on the
indoor unit.
• Check the LEV.
• Check the inverter/compressor.
• Replace the outdoor electronic control
P.C. board.
Check points
• Check the characteristic of the discharge
temperature thermistor.
• Check the connector. (CN661)
• Check the characteristic of the fin
temperature thermistor.
• Check the connector. (CN3)
• Replace the outdoor electronic control
P.C. board.
• Check the characteristic of the evaporation
temperature thermistor.
• Check the connector. (CN661)
• Check the characteristic of the outdoor
heat exchanger temperature thermistor.
• Check the connector. (CN661)
• Check if the connection lead wires of com-
pressor are correctly connected.
• Check the characteristic of the gas pipe
temperature A thermistor.
• Check the connector. (CN662)
• Check the characteristic of the gas pipe
temperature B thermistor.
• Check the connector. (CN662)
• Check the characteristic of the gas pipe
temperature C thermistor.
• Check the connector. (CN662)
• Check the characteristic of the gas pipe
temperature D thermistor.
• Check the connector. (CN662)
• Check if the connection wires between
outdoor electronic control P.C. board and
power board are correctly connected.
• Check if the connection wires between
noise filter P.C. board and power board are
correctly connected.
• Check the inverter/compressor.
• 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
refrigerant cycle.
• Check the outdoor unit air passage.
• Check the outdoor unit air passage.
• Check the outdoor fan motor.
• Check the power module.