Supplementary bonding new kitchen sink

[Eyespy999]

Hi there,

i have helped a friend fit a new stainless steel sink, replacing the old one that's about thirty years old.

all of the new pipe work is new copper pipe with flexible tap connectors.

the old sink wasn't bonded, do we need to look at bonding the new sink and if so what are the recommendations?

the incoming main has a 10mm Earth wire attached to it.


thanks in advance.

 

[ShaunCorbs]

have a word with a sparky and get him to test it, and he will tell you yes or no

 

[lame plumber]

you could actually make it lethal if you get bonding wrong, leave it to the sparkies.

 

[Worcester]

Based on your comments it is more than likely that the earthing and possibly bonding need upgrading, get a sparks in. The regs covering it are quite complicated depending upon TT, TNC-S etc. No, I'm not going to explain more

 

[joni os]

Assuming by incoming main you mean water and not electric then the 10mm bonding should suffice provided you have a 17th edition consumer unit. Had all the pipework been copper without flexible hoses, then sink would be effectively bonded through pipework. Bonding sink to copper pipes below flexible hose usually cheaper than electrician, even if unnecessary.

 

[chris watkins]

No, you do not bond sinks, there is no requirement under Part P or BS7671 17th.

 

[joni os]

No, you do not bond sinks, there is no requirement under Part P.

This is true provided all parts of electric installation are to current standard. Where you have a 1960s consumer unit with no RCDs it is not so clear. Standards should be read as a whole.
Cherry picking parts can be dangerous.

 

[chris watkins]

This is true provided all parts of electric installation are to current standard. Where you have a 1960s consumer unit with no RCDs it is not so clear. Standards should be read as a whole.
Cherry picking parts can be dangerous.

Very true but was it ever a good idea to supplementary bond a metal sink ? & if so why.

I believe a heating engineer once killed someone when & incorrectly wired programmer made a s/steel sink live through the earth / bonding.

10mm2 would suggest you want to include it as part of the Protective Equipotential Bonding which should be limited to the extraneous conductive parts such as incoming water & gas/oil pipes, ducts & structural metal, shouldn't it?

 

[stani]

Bonding of sinks went out with the 15th edition, there is no mention, therefore no requirement under the 17th edition.

 

[joni os]

Many 1960s houses were wired according to 13th edition rules, it is not uncommon to encounter these properties with wiring unchanged. Bonding of metal baths, radiators etc. was considered prudent to ensure that if contact made with live conductor a path to earth was available to blow fuse. Applying, in part, 17th edition rules, to wiring of a different standard, requires caution.

 

[thompsonbrown]

Supplementary bonding in domestic situations is normally only required in bathrooms - and under the 17th Ed then only under certain circumstances. Check with a electrician if unsure.

 

[lame plumber]

from my simple understanding it is all down to potential for a voltage and your meter reads the potential difference, but if it is all gone pear shaped your little meter can show a zero voltage across 2 connection although there is 240 in each!!! or so my sparky tried to explain to me recently. So imho gas is safer as it smells, you can only smell electrics when its gone wrong and it smells of burnt pork!

 

[Worcester]

So imho gas is safer as it smells, you can only smell electrics when its gone wrong and it smells of burnt pork!

Half burnt gas doesn't smell (CO) it kills At least lectrix sparks as well
lol

 

[plumben]

from my simple understanding it is all down to potential for a voltage and your meter reads the potential difference, but if it is all gone pear shaped your little meter can show a zero voltage across 2 connection although there is 240 in each!!! or so my sparky tried to explain to me recently. So imho gas is safer as it smells, you can only smell electrics when its gone wrong and it smells of burnt pork!

I was told by a spark that burning cables smells like fish when there in the process of starting to melt