Mitsubishi Electric City Multi CMB-P1016NU-G, Service Handbook

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[
IX
Troubleshooting ]
-7- Inverter
ΠReplace 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.
ΠReplace the defective components if the inverter is found to be defective.
ΠIf 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 Measure/inspection item
[1] Inverter related errors
4250, 4220, 4230, 4240, 4260, 5301, 0403, 5110 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.
[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) -
[3] if the compressor is in operation.
[5] The compressor vibrates violently at all times or makes an abnor-
mal sound. See (2)-[3].
[6] 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(heat source)
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.
[7] 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.