What size Earth Bonding Cable should be used in the kitchen?

[Spark123]

Extract from an article on the iee website (earthing plastic pipes):
Please note, there is no specific requirement to carry out supplementary bonding in domestic kitchens, wash rooms and lavatories that do not have a bath or shower. That is not to say that supplementary bonding in a kitchen or wash room is wrong (it would be wrong for plastic pipes) but it is not necessary.

 

[TANNERS]

of course, so you no longer have to, does that mean don't do it

if not, why not, and where does it say not to???????????/

sorry 2 b a pest shag

 

[Pensdown]

7671 Would be a very big book if it listed everything you didn't have do.

 

[TANNERS]

BUT IT WOULD LIST IT IF IT WAS DANGEROUS TO DO SO

 

[TANNERS]

Extract from an article on the iee website (earthing plastic pipes):
Please note, there is no specific requirement to carry out supplementary bonding in domestic kitchens, wash rooms and lavatories that do not have a bath or shower. That is not to say that supplementary bonding in a kitchen or wash room is wrong (it would be wrong for plastic pipes) but it is not necessary.

THATS NOT TO SAY ITS WRONG

 

[Spark123]

It's not wrong, there is just no requirement under BS7671 to carry out supplementary equipotential bonding of metallic pipework in a kitchen. This is owing to a BS7671 not considering a kitchen to be a location of increased risk due to naked and wet bodies. (Keep it clean lads!!)

(and please turn caps lock off - it's considered to be shouting )

 

[baxpoti]

Note on kitchens,
metal waste pipes in contact with Earth may be extraneous-conductive-parts and should be main bonded back to the Main Earthing terminal!

 

[TANNERS]

"You don't "want to", because it is no longer recognized by the regs.

Supplementary may be fitted in commercial kitchens if the designer deems it necessary, but in dom kits it has now been decided against.

One of the reasons is that it can create parallel earth paths & can actually make the installation more dangerous rather than safer."

which would be WRONG to make an installation more dangerous.....

 

[JohnD]

.....One of the reasons is that it can create parallel earth paths & can actually make the installation more dangerous rather than safer.

which would be WRONG to make an installation more dangerous.....

I have considerable difficulty in understanding how Supplementary Bonding, which makes a bathroom safer, can make a kitchen more dangerous.

I am ready to be enlightened...

 

[baxpoti]

I have considerable difficulty in understanding how Supplementary Bonding, which makes a bathroom safer, can make a kitchen more dangerous.

I am ready to be enlightened...

Few people stand naked in 4in of water in their kitchen (there's always the exception)

 

[securespark]

You don't "want to", because it is no longer recognised by the regs.

Supplementary may be fitted in commercial kitchens if the designer deems it necessary, but in dom kits it has now been decided against.

One of the reasons is that it can create parallel earth paths & can actually make the installation more dangerous rather than safer.

Well, To be fair, this is the view of Paul Cook (I have spoken to him personally on many occasions when he was on the technical team at the IEE - he no longer works there) not the IEE itself. Note his use of the word "can" and not "will".

If I had to join him and put my neck on the line, I would say the difference between kitchen & bathroom (apart from greatly reduced body resistance as mentioned already [cheers!]) is that in a kitchen, supplementary bonding does not tie every cpc to the pipework et al. like it does in the bathroom.

Hence the possible parallel earth paths.

That is my understanding of it.

 

[bernardgreen]

One consideration in a kitchen is that a fixed appliance such as a metal framed electric cooker may lose its earth connection and float. Leakage in an element brings the cooker frame up to live potential.

If the kitchen sink is bonded to earth and someone touches cooker and sink at the same time they have a live to earth path through them.

If the kitchen sink is not bonded then the impedance of the path is ( maybe ) higher and the current through the body is ( maybe) lower.

As the kitchen sink ( unless fitted with waste disposal unit ) has no electrical connections it does not in theory need earthing. But it is "earthed" via the pipe work ( or at higher impedance by water if the pipes are plastic. )

It seems to be a compromise between conflicting requirements of the various scenarios that could happen in a kitchen.

Supplimentary bond the cooker is one suggestion.

 

[TANNERS]

but if you want to 4mm is fine between pipes and sink
no need to go to cu

You don't "want to", because it is no longer recognised by the regs.

Supplementary may be fitted in commercial kitchens if the designer deems it necessary, but in dom kits it has now been decided against.

One of the reasons is that it can create parallel earth paths & can actually make the installation more dangerous rather than safer.

not my words. taken from securespark Posted: Sun Jan 14, 2007 10:42 am

i am of the oppinion to bond kitchen

 

[securespark]

Can you explain why?

 

[JohnD]

I am quite happy to supplementary-bond in my own kitchen.

Because:
The incoming cold-water main has been main-bonded where it comes out of the floor. So too is the iron gas-pipe where it enters in the garage.
The boiler and its pipes have been supplementary bonded (and since the rads are connected with soldered copper they form part of the circuit). All these pipes are also supplementary-bonded in the kitchen above.

So I would prefer everything to be at the same potential.

I had not thought about the cooker before but maybe that should be included.

I always encourage my guests to cook naked

see also http://nakednigella.com