Circuits earthed on metal box/conduit: Does it need a rewire?

[davesparks]

If it's a point for point rewire then it should be relatively cheap as its just pulling new cable in to existing conduit.

 

[rewireIT]

Get a spark in that knows what he's doing. Suggest he read the regs book that he's supposed to keep in his van.

 

[Ratmeister]

If it's a point for point rewire then it should be relatively cheap as its just pulling new cable in to existing conduit.

There's so many sockets and circuits though, it would cost a fortune in labour I assume. There's 8 offices within the warehouse in total that are all done the same way.

 

[Ratmeister]

Get a spark in that knows what he's doing. Suggest he read the regs book that he's supposed to keep in his van.

He told me straight out that metal conduit used as earth is not allowed in new installs.
He also told me that changing the CU meant the entire install had to be treated as a new install.
I'm trying to work with it for now and I hope he'll have a read of the regs before he returns after my subtle prompting.

 

[littlespark]

The regs ask for a cpc on every circuit... whether that be a separate earth wire, steel conduit, or the steel strands around a heavy duty armoured cable. Steel conduit, properly installed, is the most substantial of any of these.

 

[James]

I have had similar discussions with clients and other electrical contractors working the same site.
sometimes it comes to a meeting with a client and contractor and myself.

I normally stay fairly quiet, just put my point across at times.
Eventually it will come down to the other guy telling me in front of the customer that I am wrong and it has to be done "this way" because it is "against the regs" to do what i suggest and that i should go away because i don't understand.

it always makes for an interesting few minutes when I place a copy of the regs book on the table and ask them to point it out.

I have found over the years that a lot of people confuse the way they were taught it should be done with an imaginary regulation specifying that it must be done that way.

p.s. To this day, I have never walked out of a meeting like that feeling embarrassed that i had got it wrong, you can normally tell you are on a winner when your opponent keeps telling you its against the regs but will never tell you which one.

 

[rewireIT]

Exactly as James says - just ask him to point out what regs it contravenes and where it specifies a DB change means existing wiring, accessories and containment has to be treated as new. He won't be able to show you them because they don't exist.

 

[davesparks]

He told me straight out that metal conduit used as earth is not allowed in new installs.
He also told me that changing the CU meant the entire install had to be treated as a new install.
I'm trying to work with it for now and I hope he'll have a read of the regs before he returns after my subtle prompting.

Someone like that is unlikely to change their mind based on a customers research from the Internet or advice from a forum.

The second point is an unfortunately common misconception which is quite prevalent in domestic work but usually less so in commercial.

It should be pretty obvious that replacing a distribution board on an existing installation does not magically change anything about the existing installation or somehow turn it into a new one.
Yes whoever does the job will need to ensure that the installation is in a safe condition for continued use, but they don't have to do everything that would be necessary to make it fully compliant as if it was installed today.

 

[Risteard]

Thanks Dave, if you were my electrician my life would be a lot easier. I've asked them to fully test the circuits today. If the readings are too high and he insists on a rewire then I'll get someone else in for a second look.

In fairness very few electrical contractors would have test equipment to perform high current continuity tests on containment now.

 

[davesparks]

In fairness very few electrical contractors would have test equipment to perform high current continuity tests on containment now.

Yes but it can be hired for a relatively small cost.

 

[Risteard]

Yes but it can be hired for a relatively small cost.

Yes, agreed. I suspect many aren't aware of the need for a high current test though.

 

[Ratmeister]

I was speaking to a friend of a friend today who is qualified to do NICEIC work. He was saying NICEIC actually go above and beyond the 18th edition wiring regulations at times and have stricter requirements. Anyone know if this sort of thing is indeed true? I thought the 18th edition regulations were the bible to base all current arguments on.

 

[Risteard]

I was speaking to a friend of a friend today who is qualified to do NICEIC work. He was saying NICEIC actually go above and beyond the 18th edition wiring regulations at times and have stricter requirements. Anyone know if this sort of thing is indeed true? I thought the 18th edition regulations were the bible to base all current arguments on.

I wouldn't strictly agree that that's true, although I suppose individual Area Engineers may have differing interpretations of the requirements. After all everyone takes things up differently.

 

[davesparks]

I was speaking to a friend of a friend today who is qualified to do NICEIC work.

There's no such thing as being qualified to do NICEIC work.

The NICEIC is an organisation who run a scheme that electrical contractors can sign up to if they choose.
It is the company which is registered with the NICEIC and not the individual electricians. Each member company has one (or one per branch of the company for big companies) 'qualified supervisor' who undergoes the annual assessment and is responsible for counter-signing all certificates issued and ensuring that all work done by the company is compliant.

He was saying NICEIC actually go above and beyond the 18th edition wiring regulations at times and have stricter requirements. Anyone know if this sort of thing is indeed true?

The NICEIC don't go above and beyond the regulations, they assess contractors for their compliance with the regulations through annual assessment visits. They also check that contractors are insured, comply with health and safety law and certify jobs properly.

In my experience of these assessment visits they will advise on ways that we could go above and beyond the regulations, but often this seems down to the personal preference of the assessor and not based on an NICEIC rule book.

I thought the 18th edition regulations were the bible to base all current arguments on.

The 18th edition sets out the minimum requirements for electrical installations which, if followed, are viewed by the HSE as likely to fulfill the requirements of the law.

 

[rewireIT]

I was speaking to a friend of a friend today who is qualified to do NICEIC work. He was saying NICEIC actually go above and beyond the 18th edition wiring regulations at times and have stricter requirements. Anyone know if this sort of thing is indeed true? I thought the 18th edition regulations were the bible to base all current arguments on.

It's not relevant what NIC expect, they're not an authority. All that matters is regulations and the installers interpretation of them. Either way, what the original spark has told you isn't true under any interpretation of any regulation. I'd suggest just binning him off and getting someone who knows what they're doing and isn't trying to make a fast buck out of you.