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A Shocking Experience

Several years ago I came close to getting electrocuted in the shower. While having a shower I noticed a strongle tingle when I touched the taps, so I checked with a DMM and found there was AC between the taps, showerhead etc and the wet floor. Strange, so we called in an electrician to check what was going on. Turned out the shower floor had a metal tub underneath - looked like lead - which extended up into the wall cavity. On the other side of one wall was the kitchen with a GPO near floor level for the fridge. The wiring was the old rubber insulated type which had gone brittle - and the edge of the tub was scraping the active ! So the wet shower floor was only insulated from the mains by the deteriorating rubber. The Sparky replaced the GPO wiring with TPS, bent the metal away from the GPO and said we were lucky the fault only showed a high resistance and the metal hadn't gone in another mm.

Reply to
fritz
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Many years ago I discovered that all the TV antenna sockets in a French apartment block were live. I told the manager, who called in an electrician who clearly didn't believe it and was muttering about small current leaks. It was definitely a case of "Pardon my French" when he realised that I was right. I knew I was - you can't normally illuminate an mains incandecent lamp by connecting it between an antenna socket and a hotwater radiator (hey - free power!).

Turned out someone had put a screw into their wall, and it had penetrated a power cable and the antenna cable, but somehow managed to avoid shorting anything.

I performed the experiment with the lamp because I'd been getting tingles from connections to a computer that was also connected to the TV. I had likely touched a live mains connection multiple times while myself being insufficient earthed for it to kill me.

Sylvia.

Reply to
Sylvia Else

I still get the shivers about this one, although it occurred many years ago.

I was working with an American engineer on a plantsite in a country where electrical licences hadn't been heard of at the time, we were commissioning

440 volt drives in a sub. You check the wiring and insulation, do a dry start with the main fuses out, then when it all looks OK, you ram the fuses into the stabs and check the motor direction. I was working at one end of the sub, and when I looked, my colleague was sitting on the floor looking very shocked, although he was physically OK.

What this guy was doing to save time was to defeat the door interlock by pushing a welding rod into a little hole, so that he could open the door with the isolator closed. in that condition the top fuse stab would have been live at 440, right in front of his eyes. That way, he could do some checks quickly. The plan was then to close the door, open the isolator, reopen the door and insert the fuses.

The guy had shoved the fuses into the stabs *with the isolator closed*. The drives were in the 100 KW range, so the fuses were about the sizes of a milk carton, with a ceramic body and metal ends that fitted the stabs. 3 times, he did it without his hands touching the metal at the ends!!!

I bet that's something he'll never forget.

Reply to
Bruce Varley

I remember when I was young, some guys in a grocery store trying to move a display refrigerator that would have been about

10' long, and 4' H x W. At one point one guy collapsed on the floor

Turned out that he had dropped it onto/ran over a live power cable, and he got a massive shock as he was still firmly holding onto the metal unit from moving it.

I presume now that it was turned off and unplugged (therefore no earth to it) and must had cut a live cable that was feeding something else . They got everyone out, an ambulance came, we heard the next day that he didn't make it. The floor was likely damp and this didn't help either.

Just because something is unplugged, doesn't mean that it is totally safe, as if metal it may touch other live things.

Reply to
kreed

I knew a guy who tried the same idea with the interlocks on a 5MW peak primary radar modulator cabinet. The EHT supply was several hundred KV which arced over to the steel rule that he was carrying in the leg pocket of his overalls. They did manage to save his leg, but he never walked the same way again.

Reply to
keithr

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