The code kind of assumes every step of the installation, the grounds, bonds, continuity etc is and has been done correctly. A breaker is really better but that’s a pain, eliminates the potential for ground fault to the first device but somehow that would need to be thought thru.
There are miles of ungrounded NM cable still in use, earliest manufactured in the late 1930s It was cloth jacketed, and BULKY. I’d guess the insulation & jacket was linen impregnated with rubber. The jagged jacket cuts tend to cut the insulation in typical installations. The spirals of jacket steel tend to serve as inductance coils, generating heat while not conducting enough current to trip a breaker.
The shop is an old and run down, with a concrete floor right on top of the dirt, but so far the wiring has been fine for years. The machine seemed to shock me worse when my feet were wet, but it even gave a nasty zap when wearing neoprene boots and leather gloves to change the belt, or when sitting on a stool with my feet not even on the ground. I put a copper wire from the grinder to the floor to ground it when I thought it was static electricity or something, to no effect.
The male end of the cord had the ground stem removed which allowed the cord to be plugged into the ungrounded duplex outlet incorrectly, allowing the cord to have reverse polarity. All conditions existed, including unsafe cords, ungrounded wiring, the absence of GFCI duplexes, and a definite grounded location where the deceased was working. Reversed polarity, extension cord with a ground prong missing, plugged upside down into ungrounded duplex receptacle, second story workshop.
05-09-2007, 06:48 AM #22 Owner of a repair shop I used to work at, had a big angle grinder nail him across his wrist. 05-09-2007, 03:26 PM #35. 05-09-2007, 03:53 PM #36 I had a near miss with an angle grinder a few years back. I took one hand off the grinder to steady the work, and as soon as I did that the grinder kicked and ran up my left hand.
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