Earthing in kitchen

[Chris French]

A metal kitchen sink will probably be earthed anyway via the pipework (assuming metal pipework of course.

And what about all the other earthed metalwork in the kitchen - e.g. in my case the gas hob and oven (bare metal parts, like the trim the toaster (dualit, bare metal), microwave.

My BIL did get a shock from the hob. We have a rice cooker with a stainless steel exterior which is earthed.it was plugged in next to the hob. He touched both (one with each hand) whilst cleaning up and got a good shock from them.

Turns out there was an live > earth fault in a socket hidden away behind the cupboards, which meant the rice cooker exterior was live. It was in our early days here and all we had was an old ELCB protecting the installation, which really wasn't bothered by this fault Nowadays the RCBO would have tripped out long before of course

Chris French

[Syd Rumpo]

Really, it's uncommon. Most electrocutions [a portmanteu - 'electrical execution'] are from digging up high voltage cables or contacting overheads in some way. Domestic mains based deaths are very rare.

That's not to say you won't fall off the ladder and bang your head.

Cheers

[John Rumm]

Its not a wet room, its a kitchen. And we are discussing the main equipotential bonds, not supplementary bonding (which is not required for kitchens)

[John Rumm]

Not any more - kitchens were removed from the list of "special locations" in the latest revision.

[John Rumm]

There is no requirement to earth (or bond) a sink. Its not an extraneous bit of metalwork - i.e. there is no way it can introduce a potential into the room.

However it is quite likely earthed indirectly by virtue of being connected to bonded pipework. (unless all the plumbing is plastic)

[John Rumm]

And indeed similar circumstances have resulted in fatalities. (last case I remember was a metal rack made live by a screw through a cable, and the user touching that and her leg touching the earthed metalwork of a dishwasher).

A very strong demonstration of why RCDs are such a good idea.

[John Rumm]

The government figures from around the time of the into of part P suggested about 20 deaths per year in the UK. However they latter admitted that included deaths from use of appliances as well as those caused by fixed wiring (to which part P was applied). The deaths due to fixed wiring were therefore less than 2 per year (and hand been falling year on year). Needless to say the intro of part P increased that.

However its worth noting that death is not the only bad outcome, there are a significant number of people (million+) who receive a shock each year, and a large number who suffer serious injury - many with permanent effects. So focussing on deaths alone is missing the bigger picture.

[John Rumm]

Probably that Turkish cable manufacturer that got kicked out of BASEC for selling undersized conductor cable not so long ago ;-)

[tony sayer]

Valid argument that one. I think it was referred to in an IET document a while ago somewhere....

[meow2222]

Sockets & lighting need an earthling in them, kitchen sinks don't.

NT

[Adam Funk]

I guess it could be argued that some of the appliance deaths would be prevented by slapping everything on RCDs...

True. And I wonder about the harm done by having putting circuits on RCDs, especially shared RCDs.

[Andy Burns]

[polygonum]

Have to be very small ones.

[meow2222]

a bristly alien :)

NT

[ARW]

What harm?

[Cursitor Doom]

I'm guessing the people that evaluate case histories of how accidents happen and formulate codes of practice accordingly have concluded that earth bonding in kitchens is the lesser of the evils and perhaps is statistically less likely to result in bad outcomes than letting everything float. Just a guess...

[Chris French]

I assume Adam F means things like lights going off when the RCD trips, meaning people have to get around the house in the dark.

More of a problem when they just used to stick one on the whole system obviously.

[ARW]

I wonder how many deaths a year are caused by power cuts? And don't forget all of those people with pre pay meters that often have the electricity switched off as they have not topped up the meter.

Even in a power cut you seldom have total darkness.

[John Rumm]

Most of them probably...

Indeed, just slapping on RCDs without any care and planning is not good eaither (hence the deprecation of the 15th edition style of "whole house" RCD installs.

[rick]

Unless using plastic plumbing