earth bonding (sigh)

[drizzt]

So I've recently had drainage and a water supply installed into my garage (to move the washing machine & tumble dryer in there). The water supply is blue plastic pipe in the middle with copper on both ends.

There was already power in the garage supplied from a spur in the kitchen, an there's no problem with that (so I am told)

However, one thing that has come up is the fact that the copper in the garage isn't bonded.

The electrician I am using to check over the house say that the bonding needs to go right back to the CU.

I understand a little about why bonding is necessary but I don't understand why you can't simply (possibly stupidly) ...

* connect the copper in the garage to a local spike or ...
* connect the copper in the garage to the supplied earth or ...
* connect the copper in the garage to the copper in the kitchen

... which all seem a much simpler and less ugly solution that going all the way back to the CU which incidentally is the other end of the property!

 

[ricicle]

To be honest, if it is MDPE I wouldn't be worried about not bonding it.

 

[JohnW2]

So I've recently had drainage and a water supply installed into my garage (to move the washing machine & tumble dryer in there). The water supply is blue plastic pipe in the middle with copper on both ends.

Do I take it that the plastic pipe turns into copper before it enters the garage? If so, does the join occur above or below ground (i.e. does the copper pipe entering the garage have any underground parts?). If there is no underground copper pipe, it very probably would not need bonding.

There was already power in the garage supplied from a spur in the kitchen, an there's no problem with that (so I am told). However, one thing that has come up is the fact that the copper in the garage isn't bonded. ... The electrician I am using to check over the house say that the bonding needs to go right back to the CU.

OK.

I understand a little about why bonding is necessary but I don't understand why you can't simply (possibly stupidly) ... * connect the copper in the garage to a local spike or ...

That is, indeed, an option which you could discuss with yourelectrician.

* connect the copper in the garage to the supplied earth or ...

If by 'supplied earth' you mean the 'earth' wire in the electrical cable supplying the garage, that would not be 'fat' enough to be adequate to be used as a bonding conductor.

* connect the copper in the garage to the copper in the kitchen

Connecting one copper pipe to another not acceptable as main bonding, but there may be another possibility here for you to discuss with your electrician. If there is pipework (the incoming water supply) in the kitchen which already has main bonding ('back to the CU') it may be possible to extend that bonding (using suitable large cable) to the garage for bonding the garage pipework. Some electricians don't like 'joins' in main bonding conductors, but there is actually nothing in the regulations which forbids it.

.. a few thoughts for you.

Kind Regards, John

 

[drizzt]

To be honest, if it is MDPE I wouldn't be worried about not bonding it.

It is MDPE yes.

 

[drizzt]

Do I take it that the plastic pipe turns into copper before it enters the garage? If so, does the join occur above or below ground (i.e. does the copper pipe entering the garage have any underground parts?).

Good point.

Yes it does turn into copper just before coming into the garage. No part of the copper comes into contact with the ground - intentionally so for longevity of the copper.

Thanks for you other points John, think I need to have more discussions with my electrician.

(edited because I can't spell)

 

[JohnW2]

Do I take it that the plastic pipe turns into copper before it enters the garage? If so, does the join occur above or below ground (i.e. does the copper pipe entering the garage have any underground parts?).

Good point. Yes it does turn into copper just before coming into the garage. No part of the copper comes into contact with the ground - intentionally so for longevity of the copper. That's for you other points John, think I need to have more discussions with my electrician.

You're welcome. If there is no underground copper pipe, I think the main thing for you to discuss with your electrician is whether the pipe needs bonding at all - as ricicle has said, it probably doesn't.

Kind Regards, John

 

[securespark]

Is he a Domestic Installer?

 

[drizzt]

Is he a Domestic Installer?

He does all kinds of electrical installations. Domestic, commercial & solar according to his website.

 

[Taylortwocities]

I think SS means is he a registered electrician?

If so, he/she should appear on this directory http://www.competentperson.co.uk

 

[drizzt]

I think SS means is he a registered electrician?

Oh sorry yes, he does appear on that site.

 

[Taylortwocities]

Then he should know if it needs bonding, or not.
Unfortunately the word "competent" is a rather random one. In the good old days, it took a few years of experience and rigorous examinations to become a trruly competent electrician.
These days one can get the "competent domestic installer" badge after a 5 week cramming session.

 

[Aragorn84]

Then he should know if it needs bonding, or not.

cept ofcourse, many folk on that list WILL be morons and WONT know when it needs bonding, simply relying on some miss-remembered rule of thumb where they just bond everything just in case.


edit: seems your edit went some way to clarifying my point!

 

[JohnW2]

Then he should know if it needs bonding, or not.

cept ofcourse, many folk on that list WILL be morons and WONT know when it needs bonding, simply relying on some miss-remembered rule of thumb where they just bond everything just in case.

Very true. However, to be fair, the particular 'borderline' situation we're talking about is one in relation to which I have seen (here and elsewhere) even genuinely competent electricians 'debating' whether or not bonding is required. If there is metal pipe entering the location which at no time goes underground, then on a dry day, either inspection or measurement would/should indicate that bonding was not required. However, some seem to feel that they need to consider what the situation would/might be under adverse weather conditions, possibly even with a degree of pooling/build-up of water/ice/snow outside the building - in which case it might become far less certain that bonding was not required.

Of course, the important underlying issue is that 'unnecessary bonding' is not only unnecessary, but can actually introduce potential hazards which would not otherwise be present.

Kind Regards, John

 

[Taylortwocities]

* connect the copper in the garage to a local spike or ...

Would , perhaps, include JohnW's thoughts

can actually introduce potential hazards which would not otherwise be present.

 

[JohnW2]

* connect the copper in the garage to a local spike or ...

Would , perhaps, include JohnW's thoughts

can actually introduce potential hazards which would not otherwise be present.

Indeed so - if one can satisfy oneself that the pipe in question would never be 'liable to introduce a potential', then it should not be bonded, if one wants to avoid unnecessarily introducing such a potential hazard. [of course, 'connecting the copper pipe to a local spike' would only be remotely safe if the entire garage installation were TT'd - that's what the OP would have to discuss with a competent electrician].

However, as I need not tell you, this is far from being a non-contentious subject. As far as I am concerned, my statement above extends to saying that one should not bond a service pipe on the consumer's side of an 'insulating section or (insulating) meter'. Whilst some here would agree with me, others would contend that the regs require them to install such bonding, even if it may unnecessarily introduce a hazard which would not otherwise be present.

Kind Regards, John