Induction Voltage

I assume the control wires are twisted pair, perhaps with shields? Shielded is better, costs more $$ though. You might have insulation corrosion that allows one leg to touch the metal conduit - sure to make problems. How old is the installation now?

Why do you think that it is triping do to induction on the control cables? Is this a new problem or has it been happening since day one of use? What in the installation methods lead you to believe that maybe the cause? How long are these runs of cable? What is the control wire functions? Types of controls? Wiring Diagram? Voltages?

Why do you think that, "transformer(especially having long control cables) trip etc due to induction voltage on control cables."

The remedial action I would take is to engage an engineer who can determine the real cause of tripping and remediate it.

Control cables do not carry high voltage/amperage. They just tell other things what to do.

In certain circumstances, long control cables in AC actuated control circuits may prevent the disconnection of contactors due to the cable capacitance present. Even if the command contacts are open, the coil current can still flow due to the cable capacitance so that the contactor remains in the On position if sufficient sealing current is present. The effect of cable capacitance depends on the design of the control current circuit.See [for instance]:

http://www.moeller.net/binary/ver_techpapers/ver949en.pdf

I had a turnkey startup for a standby generator for a new nursing home. I noticed the control wiring sharing the same conduit with the block heater circuit. I notified the engineer, who got the plans out and saw that the plans called for a separate conduit run. I don't know what the remedial action was, because I left when the engineer blew up. I think it might have had something to do with the conduit runs entering the new foundation below grade level.

Dear Mr.giri,

You have not mentioned whether the power cable and control cable is fixed side by side.

If so it is to be seperated by a minimum distance of 1 Metre or the control cable should be shielded. You have also not mentioned the type of cable used. Replacing the existing control cable with a shielded type will be costly. Hence seperate them so as to have 1 Metre distance.

Pl. inform this Forum how the problem is solved.

DHAYANANDHAN.S