Troubleshooting Check Table - Mitsubishi Electric MXZ-32SV-E1 Service Manual

12-3. TROUBLESHOOTING CHECK TABLE

Note . LED indicates "00" in the normal status.
7-segment LED display
00
❈
If there is defect in the following parts(electronic control P.C. board, relay P.C. board, high pressure
switches(63H1,63H2),indoor /outdoor fan motor , or indoor coil thermistor), the compressor may stop even with the display
remained at " 00 ".In any case, reset the breaker and check the above-stated parts.
Symptom
Display Detecting method
a a 4 4
Outdoor power system abnor-
mality
(A4)
a a 3 3
Outdoor electronic control P.C.
board abnormality
(A3)
p p 1 1
Indoor unit and LEV abnor-
mality
(P1)
Symptom
Display Detecting method
e e 9 9
Evaporation temperature ther-
mistor abnormality
(E9)
e e 6 6
Discharge temperature ther-
mistor abnormality
(E6)
f f 8 8
Fin temperature thermistor
abnormality
(F8)
a a 8 8
Overcurrent protection
(A8)
d d 6 6
Discharge temperature over-
heat protection
(d6)
d d 4 4
Fin temperature overheat pro-
tection
(d4)
d d 7 7
High pressure protection
(d7)
f f 5 5
Room-A gas pipe temperature
thermistor abnormality
(F5)
f f 6 6
Room-B gas pipe temperature
thermistor abnormality
(F6)
f f 7 7
Room-C gas pipe temperature
thermistor abnormality
(F7)
p p 9 9
Room-D gas pipe temperature
thermistor abnormality
(P9)
Error mode
Normal
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, the
compressor stops operation.
When the nonvolatile memory data cannot be read properly on the out-
door controller board
When the drain abnormality is detected in the indoor unit and the indoor
main coil temperature is too low, or when any abnormality is detected in
the components of indoor unit
Outdoor unit stops and restarts every 3 minutes.
Detecting method
The compressor stops when a short or open circuit occurs in the evap-
oration temperature thermistor during compressor running.
The compressor stops when a short or open circuit occurs in the dis-
charge temperature thermistor during compressor running.
The compressor stops when a short or open circuit occurs in the fin tem-
perature thermistor during compressor running.
When over current is applied to the power module, the compressor
stops and restarts in 3 minutes.
When the discharge temperature thermistor detects 116˚C or above, the
compressor stops and restarts operation in 3 minutes.
(Protection will be released at 100: or below.)
When the fin temperature thermistor detects 89˚C or above, the com-
pressor stops and restarts operation in 3 minutes.
When the compressor starts, primary current or output voltage stops the
compressor and restarts in 3 minutes.
When a short or open circuit occurs in the Room-A gas pipe
temperature thermistor.
When a short or open circuit occurs in the Room-B gas pipe
temperature thermistor.
When a short or open circuit occurs in the Room-C gas pipe
temperature thermistor.
When a short or open circuit occurs in the Room-D gas pipe
temperature thermistor.
26
Check points
• Inverter output
• Compressor
• Outdoor electronic control P.C. board
• Check the abnormality indication on the
indoor unit.
• LEV
Check points
• Check the characteristic of the evapora-
tion temperature thermistor. Refer to F F
"Check of thermistor".
• Check the contact of P.C. board connec-
tors.
• Check the characteristic of the discharge
temperature thermistor. Refer to
F F "Check of thermistor".
• Check the contact of P.C. board connec-
tors.
• Check the characteristic of the fin temper-
ature thermistor. Refer to F F "Check of
thermistor".
• Check the contact of P.C. board connec-
tors.
• Check the inverter and compressor.
Refer to E E "Check of 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 refriger-
ant cycle.
• Check the outdoor unit air passage.
• Check the outdoor unit air passage.
• Check the power module.
• Check the outdoor fan motor. Refer to G G
"Check of fan motor".
• Amount of gas
• Outdoor unit air passage.
• Check the ball valve.
• Room A gas pipe temperature thermistor
characteristic.
• Contact of P.C. board connectors.
• Room B gas pipe temperature thermistor
characteristic.
• Contact of P.C. board connectors.
• Room C gas pipe temperature thermistor
characteristic.
• Contact of P.C. board connectors.
• Room D gas pipe temperature thermistor
characteristic.
• Contact of P.C. board connectors.