Owner manual

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6.3 Motor filter

Advantages of using a motor filter:

• The motor filter reduces capacitive currents caused by parasitic

cable capacitances.

• The slope of the motor voltage (dv/dt) is limited to 500 V/µs.

Motor filters are always required for:

• unscreened cables longer than 100m.

• screened cables longer than 50m.

• when using motors which do not have suitable insulation for

inverter operation. (Observe data of the motor manufacturer.)

Please note:

• Install the motor filter as close as possible to the inverter

- Maximum cable length 5 m

• Connect +U

and -U

of the motor filter only to the inverter

terminals of the same designation.

• Select the control mode "V/f characteristic control"

(C006 = -0-). The control "magnetizing current control" is not

permissible.

• The chopping frequency must be at least 4 kHz.

• The max. permissible output frequency is 300 Hz.

• The inverter is loaded in addition to the motor current with

approx. 12% of the rated filter current.

• The voltage drop across the motor filter at rated current and

rated frequency (f

= 50 Hz) is 2 to 3% of the inverter output

voltage.

• For motor cable lengths > 100 m (screened) and > 200 m (un-

screened) a motor supply filter should be used.

• With unscreened motor cables it should be tested whether the

system complies with the interference levels required for the CE-

EMC conformity.