Outdoor Unit Troubleshooting Table - Mitsubishi Electric MSC-07RV Service Manual

<OUTDOOR UNIT> (Only MXZ-18/32RV)
(1) Troubleshooting table
Note . LED indicates "00" in the normal status.
7-segment LED display
<MXZ-32RV> If there is defect in the following parts(electronic control P.C. board, relay P.C. board, high pressure switch-
es(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 1 1 Outdoor refrigerant system
abnormality
(A1)
(LEV abnormality)
a a 3 3
Outdoor controller board
abnormality
(A3)
p p 3 3
<Only MXZ-32RV>
Compressor temperature
(P3)
abnormality
p p 1 1
Indoor unit and LEV abnor-
mality
(P1)
Symptom
Display Detecting method
e e 8 8
Suction temperature thermis-
tor abnormality
(E8)
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)
00
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 compressor operation has been interrupted by LEV protection
continuously five times, the compressor stops operation.
When the nonvolatile memory data cannot be read properly on the out-
door controller board
When the compressor has remained OFF for continuous thirty minutes
by inner thermostat function
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.
The compressor stops when a short or open circuit occurs in the suction
temperature thermistor during compressor running.
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 120˚C or above, the
compressor stops and restarts operation in 3 minutes.
((Protection will be released at 80; or below.)
When the fin temperature thermistor detects 88˚C or above, the com-
pressor stops and restarts operation in 3 minutes.
Error mode
Normal
Outdoor unit does not operate.
Detecting method
Detecting method
126
Check points
• Inverter output
• Compressor
• Amount of gas
• Outdoor control P.C. board
• Contact of LEV board connectors
• Outdoor control P.C. board
• Outdoor air cycle
• Amount of gas
• Outdoor fan motor
• Outdoor heat exchanger
(dust adherence)
• Check the abnormality indication on the
indoor unit.
• LEV
Check points
• Check the characteristic of the suction
temperature thermistor. Refer to L L on
page 138.
• Check the contact of P. C. board con-
nectors.
• Check the characteristic of the evapora-
tion temperature thermistor. Refer to L L
on page 138.
• Check the contact of P. C. board con-
nectors.
• Check the characteristic of the discharge
temperature thermistor. Refer to L L on
page 138.
• Check the contact of P. C. board con-
nectors.
• Check the characteristic of the fin temper-
ature thermistor. Refer to L L on page
138.
• Check the contact of P.C. board connec-
tors.
• Check the inverter and compressor.
Refer to G G to K K on page 136,137.
• 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 N N
on page 139.