Chapter 6 Troubleshooting
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ter 6
However, the carrier frequency reduced may result in the increase of motor noise.Please note that
additional installation of reactor is also an effective method to solve leakage current problem.
The leakage current may increase with the increase of circuit current. Therefore, when the motor
power is higher, the corresponding leakage current will be higher too.
2) Factors of producing leakage current between the cables and its solutions:
There is the distributed capacitance between the output cables of the inverter. If the current
passing lines have higher harmonics, it may cause resonance and thus result in leakage current. If the
thermal relay is used, it may generate error action.
The solution is to reduce the carrier frequency or install output reactor. It is recommended that
the thermal relay shall not be installed in the front of the motor when using the inverter, and that
electronic over current protection function of the inverter shall be used instead.
6-3-6.
Precautions on installing EMC input filter at the input end of
power supply
1) Note: when using the inverter, please follow its rated values strictly. Since the filter belongs to
Classification I electric appliances, the metal enclosure of the filter and the metal ground of the
installing cabinet shall be well earthed in a large area, and have good conduction continuity, otherwise
there may be danger of electric shock and the EMC effect may be greatly affected. Through the EMC
test, it is found that the filter ground end and the PE end of the inverter must be connected to the same
public earth end, otherwise the EMC effect may be greatly affected.
2) The filter shall be installed at a place close to the input end of the power supply as much as
possible.