A friend of mine worked at a pizza restaurant and told me about a piece of equipment they had that would shock people pretty intensely. It was a machine that spun dough flat, into pizza shape. (For no more tired pizza chef arms). All it was, was a motor attached to a round pan. The motor would be turned on and spin the pan. But if the motor was plugged in, anyone who touched anything on this device would get a nasty shock. It was wired up neatly and correctly. I saw that the motor was grounded properly. So, my only guess is that a motor winding was energizing the device. Has anyone ever experienced any motor winding issues like this?
Another was a rather large transformer used on a CNC mill. It was attached to metal plate inside a control box. The AC power connected directly to it, hot & neutral. When on, the transformer would energize the plate it was connected to. It didn't send 120VAC to the plate, it was more like 50-60VAC differential from the plate to the earth. Obviously, enough to kill someone. I actually could work on this problem, unlike the pizza machine. I ended up placing the green, ground AC wire, to the plate to absorb the transients. Was this transformer leaking? Anyone have issues with large leaking transformers?
Cabe
