Motor Cable Length - KEB COMBIVERT F5 Reference Manual

2.2.7 Motor Cable
Length
In some conventional installations and many MRL applications, the motor
can be a considerable distance (greater than 40 feet) from the elevator drive.
Under these circumstances, the long cable length can cause high voltage
peaks or high dV/dt (rate of voltage rise) on the motor windings. Depending
on the design of the motor, the long runs can cause damage to the motor
winding. Therefore, in these installations, the use of a special dV/dt filter is
highly recommended.
The standard approved solution is a special output choke. The choke is designed
to be used with a maximum of 16kHz switching frequency and low inductance,
so it does not drastically influence the motor's equivalent circuit model.
There are three sizes available for motors rated up to 100A. All chokes are rated
for use up to 550VAC. The part numbers and current ratings are listed below.
Part Number
15Z1F04-1005
17Z1F04-1005
21Z1F04-1005
The use of a conventional line or motor choke on the output of the drive is not
recommended since the inductance value is high enough that it would distort
the values in the motor model and result in poor motor control. In addition,
these chokes may not be designed to handle the heating incurred from 16kHz
switching operation.
Technical Information
Rated Current
22A
42A
100A
15