Mitsubishi PUHY-EP250 Service Handbook page 244

[8-9 Troubleshooting Inverter Problems ]
Error display/failure condition
[1] Inverter related errors
4250, 4255, 4256, 4220, 4225, 4226, 4230, 4240, 4260, 5301,
5305, 5306, 0403
[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 shakes 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.)
HWE12050
Measure/inspection item
Implement solutions that correspond to the error codes or preliminary
error codes.[7-1 Error Code and Preliminary Error Code Lists](page
145)
Refer to the following page(s). [8-9-11 Solutions for the Main No-Fuse
Breaker Trip](page 240)
Refer to the following page(s). [8-9-12 Solutions for the Main Earth
Leakage Breaker Trip](page 240)
Check the inverter frequency on the LED monitor. If the frequency indi-
cates that the units are in operation, refer to the following page(s). [8-
9-5 Checking the Inverter for Damage during Compressor Opera-
tion](page 237)
Refer to the following page(s). [8-9-5 Checking the Inverter for Damage
during Compressor Operation](page 237)
Check the inverter frequency on the LED monitor. If the frequency indi-
cates that the units are in operation, refer to the following page(s).
[8-9-7 Checking the Fan Board Error Detection Circuit at No
Load](page 237)
[8-9-8 Checking the Fan Inverter for Damage at No Load](page 238)
[8-9-9 Checking the Fan Inverter for Damage with Load](page 239)
Check the inverter frequency on the LED monitor. If the frequency indi-
cates that the units are in operation, refer to the following page(s).
[8-9-7 Checking the Fan Board Error Detection Circuit at No
Load](page 237)
[8-9-8 Checking the Fan Inverter for Damage at No Load](page 238)
[8-9-9 Checking the Fan Inverter for Damage with Load](page 239)
<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 if the inverter output wiring is not running parallel to 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 problem suddenly appeared, inverter output may have had a
ground fault. For details, refer to the following page(s). [8-9-5
Checking the Inverter for Damage during Compressor Opera-
tion](page 237)
*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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GB