Technical Data
34 BA8230
2.5.4.2 Motor choke The motor choke makes it possible to use longer cable lengths between the 8230
frequency inverter and the motor. Motor chokes reduce the output voltage rates of rise
and fall and attenuate the high frequency recharging currents caused by cable
capacitance. The motor choke is also to be installed in multiple motor applications.
The recharging current amplitudes are higher, the higher are the pulse
frequency/voltage rate of rise and the effective capacitance through the motor cables.
This means on average also higher currents can be found.
As fault currents occurring on the motor current circuit are also detected by earth
current detection, pulses may be disabled and fault shutdowns may occur when long
motor cables are used and the earth fault threshold is set too low.
The motor choke reduces these fault currents and is to be used if cable length is
excessive and the 8230 frequency inverter is operated “
without an output circuit
”, see
also Table 24.
Alternatively a 8230 frequency inverter motor filter is to be used if required for
insulation protection.
If an output choke is fitted, the motors used must be designed for the maximum
voltage ratings since a reduction in the maximum voltage amplitude can only be
expected when longer cables (approx. 150 m) are used.
To Next Page
Loading...
