View Full Version : Contactor Drop off Problem in Long Distance control Cable. cable capacitance

10-28-2010, 02:05 PM
I had experienced several times the problem of Contactor not getting dropoff for long distance cable due to cable capacitance. "e.g LCS is placed 1 KM away from MCC Motor feeder & Operator want to stop the Motor by pressing STOP Push Button & Motor is not getting STOP".

I had done many experiment like shorting the spare core & earth it with Armour. (Not Adequate)

Using 2 NC Stop Push button at LCS & when Stop is pressed entire core to contactor is earth (Work below 500Mtrs).

Third Method I had used is Connecting a capacitor between A1(Phase to Contactor Coil) & earth. Capacitor value depends on Length of cable ,no of core etc works fine for any length of cable.

Am looking for more solutions on same.


Rajesh sharma

10-29-2010, 05:38 PM
Very interesting subject But can you show the circuit.
I believe nothing to do with control cable capacitance. It is rather small.