Mitsubishi Electric PUHY-P120YHMU-A, Service Manual

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[
IX
Troubleshooting ]
- 245 - HWE0804A GB
Error display/failure condition Measure/inspection item
[1] Inverter related errors
4250, 4255, 4220, 4225, 4230, 4240,4260, 5301, 0403 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. [2] Self-diagnosis on the basis of Error Display on Re-
mote Controller and Remedy for Error.
[2] Main power breaker trip <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].
[3] Main power earth leakage breaker trip <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]
[4] Only the compressor does not operate. Check the inverter frequency on the LED monitor and proceed to (2) -
[4] if the compressor is in operation.
[5] The compressor vibrates violently at all times or makes an abnor-
mal sound. See (2)-[4].
[6] Only the fan motor does not operate. Check the inverter frequency on the LED monitor and proceed to (2)-
[6] if the fan motor is in operation.
[7] The fan motor shakes violently at all times or makes an abnormal
sound. Check the inverter frequency on the LED monitor and proceed to (2)-
[6] if the fan motor is in operation.
[8] Noise is picked up by the peripheral device <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)-[4].
*Contact the factory for cases other than those listed above.
[9] Sudden malfunction (as a result of external noise.) <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.
[THMU-A]