Earthing in kitchen

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

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)

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

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)

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.

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.

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

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

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

NT

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.

Have to be very small ones.

a bristly alien :)

NT

What harm?

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...

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.

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.

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.

Unless using plastic plumbing