How to Wire a Reversing Contactor

[rogereo]

Hello,
I am in the process of doing a small upgrade to multiple machines. It involves partially automating one axis with a motor and jog buttons where there used to be a crank handle. The type of machine itself is irrelevant, I am just adding a motorized capability to one of the manual axes.

Since I am doing  multiple machines, I though I would be sure I am doing this correctly. I am adding a reversing contactor and basically jog buttons for both directions. I am wondering the proper methodology for how to wire a reversing contactor.

The contactor has a built in mechanical lever that will prevent both directions from being energized at the same time. When one coil pulls in, the other is physically prevented from closing. The mechanical interlock is failsafe (unless it falls off someday).

Do I have to wire the controls in such a way so that when one coil is energized, the other is electrically isolated? This seems like a good idea however if someone were to press both jog buttons at the same time, the mechanical design of the reversing contactor would only allow one of the coils to close.

So is the redundant electrical interlock wiring required? Is it just good practice? or is it even necessary at all?

Thanks for any advice you can offer on how to wire a reversing contactor correctly. Initially, I thought I could get away with just using the mechanical interlock, but now I'm having second thoughts. Look forward to hearing from you guys.

[Cheller]

I'm not aware of any standard that says reversing contactors must be interlocked mechanically and electrically, however, I think it would be good practice to wire them electrically interlocked.

I don't see the reasoning why you would want to avoid that. Better safe than sorry...