Inverter Troubleshooting - Mitsubishi Electric PU(H)Y-P250YGM-A Service Handbook

[ IX Troubleshooting ]
-6- Inverter
Replace only the compressor if only the compressor is found to be defective. (Overcurrent will flow through the inverter if
the compressor is damaged, however, the power supply is automatically cut when overcurrent is detected, protecting the
inverter from damage.)
Replace only the fan motor if only the fan motor is found to be defective. (Overcurrent will flow through the inverter if the
fan motor is damaged, protecting the inverter from damage.)
Replace the defective components if the inverter is found to be defective.
If both the compressor and the inverter are found to be defective, replace the defective component(s) of both devices.
(1) Inverter related problems and countermeasures
Error display/failure condition
[1] Inverter related errors
4250, 4255, 4220, 4225, 4230, 4235, 4240, 4245, 4260, 4265,
5301, 0403, 5110
[2] Main power breaker trip
[3] Main power earth leakage breaker trip
[4] Only the compressor does not operate.
[5] The compressor vibrates violently at all times or makes an abnor-
mal sound.
[6] Only the fan motor does not operate.
[7] The fan motor vibrates violently at all times or makes an abnormal
sound.
[8] Noise is picked up by the peripheral device
[9] Sudden malfunction (as a result of external noise.)
Check the details of the inverter error in the error log at 10.[1] Table of
LED codes.
Take appropriate measures to the error code and the error details in ac-
cordance with 9. [3] Self-diagnosis on the basis of Error Display on Re-
mote Controller and Remedy for Error.
<1> Check the breaker capacity.
<2> Check whether the electrical system is short-circuited or ground-
faulted.
<3> If items cause is not <1>or <2> are not the causes of the problem,
see (3)-[1].
<1> Check the earth leakage breaker capacity and the sensitivity cur-
rent.
<2> Meg failure for electrical system other than the inverter
<3> If the cause is not <1>or <2>, see (3)-[1]
Check the inverter frequency on the LED monitor and proceed to (2) -
[3] if the compressor is in operation.
See (2)-[3].
Check the inverter frequency on the LED monitor and proceed to (2) -
[6],[7] if the fan motor is in operation.
Check the inverter frequency on the LED monitor and proceed to (2) -
[6],[7] if the fan motor is in operation.
<1> Check that power supply wiring of the peripheral device does not
run close to the power supply wiring of the outdoor unit.
<2> Check that the inverter output wiring is not in close contact with the
power supply wiring and the transmission lines.
<3> Check that the shielded wire is used as the transmission line when
it is required, and check that the grounding work is performed prop-
erly on the shielded wire.
<4> Meg failure for electrical system other than the inverter
<5> Attach a ferrite core to the inverter output wiring. (Contact the fac-
tory for details of the service part settings.)
<6> Provide separate power supply to the air conditioner and other
electric appliances.
<7> *If the error occurred suddenly, a ground fault of the inverter output
can be considered. See (2)-[3].
*Contact the factory for cases other than those listed above.
<1> Check that the grounding work is performed properly.
<2>Check that the shielded wire is used as the transmission line when
it is required, and check that the grounding work is performed prop-
erly on the shielded wire.
<3>Check that neither the transmission line nor the external connec-
tion wiring does not run close to another power supply system or
does not run through the same conduit pipe.
* Contact the factory for cases other than those listed above.
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Measure/inspection item