On Mon, 06 Nov 2017 08:49:46 +0000
Chris J Dixon wrote:

Rob Morley wrote:

I have a vintage sewing machine that I was happily using with live
shorted to the metal body, until one day I happened to ground myself
against something and felt a tingle. As long as you don't use
something like that while soaking wet and holding onto a water pipe
you'll probably be fine. So my choice would be to keep it original,
but other people may be more sensitive to/about mains voltage.

I once hired a carpet cleaner which was double insulated, but had
a metal outer case, presumably for durability. Unfortunately,
the cable had slipped through the grip, whilst still functioning,
and the live conductor had made contact with the casing. I only
realised there was a problem when it sparked to a radiator.

I wonder if an RCD would have reacted, before contact was made with a
good ground.

Luckily no harm done, and hire fee waived, but it could so easily
have been much more serious.

I tried to find figures for domestic electrocution accidents in the UK,
but it seems they don't justify a separate category so must be pretty
uncommon. I suspect that there are many "could have been much more
serious" incidents and very few "was actually rather serious" ones.

In a lifetime of messing around with electricity I've made a few things
go bang, and had a few jolts that "could have been much more serious"
(if they'd made me fall off a ladder, perhaps) but I've only had two
jolts that I wouldn't want to repeat, from a car ignition system and a
valve amp output transformer, both across the chest to a good ground
(obviously I was careless and broke the "keep one hand in your pocket"
rule). I was young and fit at the time, I wouldn't want to bet that I'm
still as resilient.