Earthing a kitchen sink - what size cable?

sufficient?

NT

NT,

OK, thanks for that.

There's no earth anywhere near two metres of the sink in any direction including straight down. Does the sink have to have a *direct* independent connection to actual earth? The rest of the internal copper pipework is earthed back to the consumer unit (in very hefty cable, which I take to be 16mm2) and thence to the incoming supply's earth; surely it would be sufficient to bond the sink to the nearest available copper pipe?

Bert

Aren't the pipes bonded? Or are they plastic? If the pipework is copper, then they should already have earth straps and green/yellow wire to them. If they have been bonded, then connect the sink to one of the straps.

socket too to be 100%. But in no way is 16mm2 needed to your sink!

Should have added that you use the same gauge cable that is already on the earth straps. :-)

I'm probably being extremely ignorant/innocent here but why do you need to earth a sink?

Is it to use with the electric hammer?

Mary

BigWallop,

Thanks for the reply.

No, the internal pipework is all copper and it is bonded, but not under the kitchen sink. The connection is in the bathroom.

Bert

Tim,

Thanks, Tim. Is that a cable from the sink to, say, the cold pipe and a jumper cable connecting the cold pipework to the hot?

It did seem a tad large, I admit.

Bert

Mary,

I agree that on the face of it it seems an odd requirement, but it just seems simpler not to argue, really. I would be interested in an idiot's-guide explanation as to why it's necessary, if anyone would be kind enough...

Bert

Presumably the theory is that it's possible inadvertently to touch something live with one hand and the sink with another, so

Yes, I never cut my cables. used to strip off insulation and then fit to earth clamp by removing the screw completely to put wire under efore tightening up again.(if that makes sense!)

Tim,

Thanks for the reply.

before

It does, except for the bit about never cutting your cables. You must cut them to length, surely?

Bert

Where on earth did you find those two bits of completely wrong information?

We've been through this multiple times - as a groups.google.com look in uk.d-i-y will show. No-one's yet been arrassed to put the Conclusion in the FAQ.

There is NO requirement to earth a kitchen sink. The IEE On-Site guide goes so far as to use almost exactly those words - i.e. it doesn't just not mention sinks under 'things wot must be earthed'; after that list, it gives another list of 'things wot you might think must be earthed but for which there ain't no such requirement'. And kitchen sinks is on that second list.

But there's a widely-read trade 'Bible', Whitfield's Guide-to-the-Regs, wot makes a big song and dance about what a good idea it is to earth a kitchen sink. It doesn't put the other side of the case - that providing a well-earthed sink to lean against (especially if you're in bare-midriff mode: middle-aged male uk.d-i-y'er on the rare hot day of summer, or fashion-conscious female young in (actual or virtual) years) you increase the harm from a touch-something-live fault.

Bottom line - it's arguable both ways, and with copper piping you're unlikely not to have it earthed thru the taps anyway. If you want to either bond it explicitly to the pipework, or earth it to a nearby socket, go ahead; but you won't find any authoritative cable size to use, because the only authoritative source doesn't require it to be done.

Stefek

direction

contributors here. There is no requirement or reason to earth a kitchen sink.

I thought from my description you'd realise it was not serious.

NT

I have a metal sink, well two actally, and they are completly isolated from earth for this reason, It's how my dads brother died many many years ago...

Sparks...

Phew! I'll tell Spouse. When I asked him about it he said that neither of ours is earthed and he thought it was a nonsense but, he said, it WAS a requirement. It will be good to tell him that it's not :-)

Mary

FWIW I didn't see any indication of you joking!

A little :-) may have helped a bit!

No, it's funnier without. Well, the result usually is ...

Mary

:-)

Didn't edition 15 of the wiring regs insist on /anything/ metal /anywhere/ having to be earthed? Or was that only the general conception of it?