Do RCDs actually work?

[ARW]

Some of the special equipment might use 10mA. But they pay a fortune for whatever work they need doing.

[Adam Funk]

Ha ha. It does give you a nice amount of room to fit the wire nuts^W^W^W^W work in, instead of squashing all the wires into a 20 mm (or whatever, ISTR there was a dispute about the actual depth) here.

[Adam Funk]

Does that mean if you eat more fruit & veg, you can drink more alcohol? ;-)

[spuorgelgoog]

Most alcohol is a fruit or cereal product :-)

Owain

[Windmill]

Can't see that N. American insulation is likely to be 3 times better than UK insulation (would be 6 times except for the lower voltage).

[Windmill]

I was. But regardless of what might be only second-order effects, it would still be interesting to know if many/any people have been killed when the circuit which killed them had RCD protection.

[Windmill]

I think that you could arrive at it in a legitimate way, by seeing if your initial assumptions were insufficiently conservative (some people killed despite the presence of an RCD) and then progrssively making RCDs more sensitive until there were few/no deaths.

Not just Germans. A mad US psychiatrist experimented on Canadians at the behest of the FBI or CIA. Decades later, some won compensation.

We've probably got a few madmen of our own, (in)human nature being what it is. Whether we'd hear about it is another matter.

[Windmill]

What disappoints me is that, just like smaller N. American sockets, ours get quite warm when passing 13 or 15 ammps.

[Windmill]

Yes, I didn't intend to make such a test!

But the resistance might not vary very much with applied voltage, or that at least was my assumption. Possibly an incorrect one.

Will do later when on-line.

Even a few would suggest that 30 mA is too high a threshold though. If you could find any.

That seems to me an easy upgrade, except for the problem of nuisance trips. I have a couple of combination convection/grill/microwave units made long ago (in Japan IIRC) for Comet, whose heating elements tripped the RCD. Neither had been used for a long time; I removed them from let property when the decorative plastic door surrounds cracked, not because that was dangerous but because the appearance made tenants nervous. One stopped causing trips after being run for an hour on a convection setting (don't ask how). Magnesium oxide insulation dried out, I'd guess. The other is still unusable. But except for that, and one circuit that had a neutral to earth fault, I haven't had much RCD trouble.

[Windmill]

Two separate issues I think: the resistance of the skin, and the capacitance of your whole body to earth, which allows those neon screwdrivers to light when touched to a live wire.

[Windmill]

I'm not so sure about passing 30 mA. And if you only pass 10 mA. a 30 mA RCD isn't going to trip at all, but what effect would that 10 mA. have?

[Windmill]

The electrolysis might cause you to get a miniscule amount of soluble tin or copper compunds in your saliva, but I doubt if it would be anywhere near enough to poison you.

[Windmill]

I'll have to try that. Sounds logical. Maybe rinse in dilute caustic soda, which someone said feels soapy because it converts the oil to soap.

Hence the (rarer) 10 mA RCDs here, I suppose.

But if one hand is on a live conductor and the other on an earthed object..........

To be pedantic, it's 1.414 times 240V or about 340V.

There used to be a few reports of people using electric mowers on wet grass, cutting the cable, and somehow getting killed. Haven't seen any recently though.

[Windmill]

Seems to me that the voltage is not too relevant; the question is how much current can it drive through you.

I wonder if anyone has been killed by a telephone? The ringing voltage is somewhere around 80 or 100 volts (and I have a relative who used to have an extension in the bathroom; hope she and her hubby heeded my warning).

[Windmill]

Hadn't seen that, but haven't been there for some time. It would work here quite nicely on short spurs which you might have in a kitchen.

An article long ago said that 240V had the advantage of producing powerful muscle contractions which stood a chance of disconnecting you from the live wire, and that the old Dutch standard of 160V. was the worst possible choice.

10 mA. RCDs seem rarer/more expensive, which is a shame.

[Windmill]

Clutching them one to each wet palm with the fingers of that hand. I think I'll retry it with some diluted caustic soda instead of water, just to see if skin oil makes much difference. And of course rinse away fairly promptly. Don't want chemical burns. Come to think of it, methylated spirits and water might be safer.

[Windmill]

Good point. But trip time might be less with a higher fault current, and that could lead to a reduced injury.

[Windmill]

And, I hope, your fridge or freezer.

Unexpected consequences are everywhere. Someone reported a spike in the UK death rate in 2007-2008.

[Windmill]

Probably an approach best described as 'make it up as you go along'.

[Windmill]

Bread's a vegetable, chips are a vegetable, white pudding's (mostly) vegetable, beer is vegetable, popcorn's vegetable.