C、 the surrounding equipment is separately earthed, which can avoid the
interference caused by the leakage current of the inverter’s earth wire when
common earth mode is adopted.
6.3.5 Leakage current and handling：
There are two forms of leakage current when using the inverter. One is leakage
current to the earth, and the other is leakage current between the cables.
1) Factors influencing the leakage current to the earth and the solutions:
There are distributed capacitance between the lead cables and the earth. The larger
the distributed capacitance is, the larger the leakage current will be. The distributed
capacitance can be reduced by effectively reducing the distance between the inverter
and the motor. The higher the carrier frequency is, the larger the leakage current
will be. The leakage current can be reduced by reducing the carrier frequency.
However, reducing the carrier frequency may result in addition of motor noise. Note
that additional installation of reactor is also an effective method to remove the
leakage current.
The leakage current may increase following the addition of circuit current. Therefore,
when the motor power is high, the corresponding leakage current will be high too.
2) Factors of producing leakage current between the cables and solutions:
There is distributed capacitance between the output cables of the inverter. If the
current passing the lines has higher harmonic, it may cause resonance and thus result
in leakage current. If 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 thermal relay not be installed before the motor when using the
inverter, and that electronic over current protection function of the inverter be used
instead.
6.3.6 Precautions for Installing EMC input filter at the input end of power supply
1) 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 shall
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