JohnF wrote:

I am using a Dayton "drum" switch on a 3 phase application that is
constantly being reversed. It's a 1hp motor connected to a rotary
table through a reduction box on a semi-auto polishing machine.
Anyway, the drum switchs are coming loose inside every so often and
contact is lost on 1 leg of the 3phase when the operator lets go of
the handle. The noise in the area is too great for anyone to hear the
buzzing of the motor running on 2 legs. 2 legs is fine for most of
what they do (it's like running with a cheepie 3 phase converter) but
takes it's toll over a period of time. There are 2 machines, one has
the smaller Dayton drum switch and the other has the same type switch
but a much larger Square D, I think, but they both have the same
basic problem.

Any suggestions for a tougher switch of some kind for HEAVY duty use?

Plug reversing is real damn hard on switch contacts. A whole bunch of current
flows for just a short time. There is a lot of arcing and contact damage. You
may be able to just buy a drum switch which is rated for a lot more current. I
don't get how a zero crossing switch can work for 3 phase since the 3 phases are
never zero at the same time, though.

If you use a reversing motor starter, you can order those as heavily built as
you need to. Hope you have a big budget, those suckers add up quick.

GWE