Here is a series of photos of a Start/Stop station for a 460VAC conveyor motor.
First one is a "before" shot. The 460 to 120V transformer secondary X2 is bonded to the frame of the transformer, but, apparently beacuse of the paint on the panel surface, there was approx 400 ohms resistance between this point, and the point at which the incoming ground and the motor ground were attached in the lower left corner.
Second pic is a close-up of the overload where the motor taps are connected. Tried to get the flash of the camera to illuminate them, but, there are indeed wires for the motor there. The starter is actually mounted on a din-rail, but the connections are about 1/4 inch from the bottom of the enclosure. No way of getting the wires out or in without removing the starter. And, this enclosure frequently gets wet inside.
Third pic is an "after" shot, after re-wiring. By using pushbuttons that took up less room in the enclosure, we were able to move the starter up and to the left. (The original PB's were so large that the original installer mounted the starter on the right, below the x-former/fuseblock so that the door would close, apparently did a "Woops" or "Oh well", being so close to the bottom of the enclosure.) "It's non-metallic, right?"
A co-worker and I originally started out intent on connecting all the ground wires at one single point, but, were so disgusted by the whole wiring job, that we ended up re-wiring the whole box.
I changed the buttons out and moved the rail and starter, co-worker Jeff R. did the re-wire.
Notice the char marks from some previous time!!! POW!!!
Barry P. (bp-redbear)