Supplementary bonding under the 15th

[Sidewinder]

OK peeps,

The 15th was in when I did my apprenticeship, however, as I was industrial, I was not really exposed to all the nuances of the domestic installations at the time.

IIRC there was an interpreted requirement for bonding all metalwork including for example window frames.

Anyone 15th literate care to explain further please?

The 15th is of a very similar layout format to the 16th and on as far as I can see though there are changes in structure slightly.

Big change in layout from the 14th though!

 

[Evans Electric]

Bonding madness was rife when the 15 th came in , all to do with interpretation I think.

Metal window frames were religiously bonded until an article pointed out the case of the poor window cleaner standing outside the equip. zone on a metal ladder , wet sponge and a differencial existing on the frame.

Also every T bar on the false ceilings were drilled and had a 6mm earth with crimp lug attached. All bloody nonsense. The daftest of all , I was shown a photo from a Birmingham Council job , it was one of those door stops that is screwed to the floor, a stainless steel half-cup containing the rubber stop , coming out of the floor was a 4mm G/Yellow cable drilled and tapped into the metal !!!!! :C

Another one, on jobs for Birmingham Council , the metal sheathing (Capping) flush in the wall had to be bonded.

And on a boiler room job once, we had to earth that lagging which was made up of an insulating foam within a thin ,flimsy silver foil outer cover.

Like trying to attach a 4mm cable lug to Bacofoil , utterly ridiculas!!!

A mate of mine used to say if you left your car at a garage for more than two days, they had to get a sparks in to bond it to their system .

 

[Sidewinder]

Deke,

This is the way I read it, as i understand it the section causing the issues was 471-11 then 471-22 through 26.

If you look at the IEE guide it gives an example of the pipework to a sink needing cross bonding to the local socket outlet circuit as one could be holding a metal kettle whilst pugged in and a tap at the same time to fill the kettle.

I know this is somewhat historic now, but I am hoping for 7 big PIR's soon and they are older premises, definitely after the 15th, but may be late 15th or early 16th.

No records what so ever!

There is a long story to that.

So I am trying to get my head around the regs at the time in some detail so that I can give eduacated code 4's

I think this is one aspect that has been relaxed!

 

[Evans Electric]

Don't forget that just because it doesn't comply with the 17th , it doesn't mean it has to be corrected . AFAIK

 

[Sidewinder]

Deke,

Exactly my point, hence why I want(ed) to know what was required under old regs as, with fault free installs then it may just be a shed full of code 4's.

 

[binky]

Wouldn't worry about previous regs, in my book anything previous to 16th needs updating as a general rule of thumb. There are exceptions such as using the adiabatic equation to calculate main earth size, and imperial cable sizes need careful scrutiny, but if you had a car 30 years old, you would not expect it to pass an MOT today, but it still needs to be good enough to drive on todays roads.

 

[Sidewinder]

binky,

There I disagee to a certain extent.

We are not talking about 30yr old installs perhaps in the way that you see them!

There is no way am I going to persuade this customer to rip out around

 

[pickleye]

Goodluck with it sw. Hope the background work pays off.

 

[SPECIAL LOCATION]

A mate of mine used to say if you left your car at a garage for more than two days, they had to get a sparks in to bond it to their system .

Do you think I need to bond my car when I put it in the garage?

?:|

 

[kme]

OK

My tuppence worth.

15th (interpretation-wise) was utterly OTT on bonding. everybody wanted to bond everything that couldbe bonded; window frames was a classic.

What I would say is this (and I don`t think its a cop-out): We`ll sort it out as & when it arises, dependant on specific circumstance (asuming I`m involved).

Actually, even if not - code 4`s would probably be site-specific, even down to the individual circumstance in question. There were such unusual interpretations of the regs possible at the time; that, IMO, some of the "extraneous" bonding made things MORE dangerous.

KME

 

[steptoe]

15th was mad, completely MAD with regards to bonding,

you probably needed your toolbox bonded to comply properly,

I remember going round a housing estate drilling window frames and brand new installed SS sinks so they could be bonded, Fin joke really,

until that poor window cleaner got a dig!

as Deke says, if it was metal then LA demanded it was bonded,

IIRC you had to have an earth strap dangling from the rear of your Steel toecap boots,!!!

or was that just the boys playing a prank on me. !!!! :Blushing

 

[Chr!s]

Paul

Several key areas for supplementary.

1, can disconnection times be met?

2, supplementary bonding was required for certain locations(look at part six).

Fundamentals remain the same.

 

[Sidewinder]

Plumber,

Pt 6 in the 15th is I&T?

I have no issues with ascertaining the disconnection times etc. or the I&T to the 17th

I am trying to ascertain which are the regs that required this under the 15th, because at the moment, all I can see from going through the 1st edition of the 15th, is that it was the ambiguity that perhaps led to misinterpretation of the requirements of the regs.

There also seems to be nothing in the IEE Guide to the 15th with regard to this.

I understand the requirements under current regs & the 16th, I know that I will be doing the PIR's to the 17th, I have no issue with this.

I am just trying to discover from people who were designing installs to the 15th which regs they considered required this bonding "overload"?

 

[Chr!s]

Paul

The change from the 14th to the 15th Edition of the IEE Wiring Regulations in 1981 created a big upheaval in the electrical installation industry as many new concepts were introduced and many existing practices were expanded or enhanced - one of those being supplementary equipotential bonding. To a great extent, the 15th Edition was based on CENELEC harmonised documents (HDs) (more so now with the introduction of the 17th Edition).

HD 384.4.41 was the basis for Chapter 41 of the 15th Edition - Protection against electric shock, which had requirements for supplementary equipotential bonding in Regulation 413-7, reproduced here:

413-7 Within the zone formed by the main equipotential bonding, local supplementary equipotential bonding connections shall be made to metal parts, to maintain the equipotential zone, where those parts -

(i) are extraneous conductive parts, and

(ii) are simultaneously accessible with exposed conductive parts or other extraneous conductive parts, and

(iii) are not electrically connected to the main equipotential bonding by permanent and reliable metal-to-metal joints of negligible impedance. NOTE - Where local equipotential bonding is provided in accordance with Regulation 413-7, metalwork which may be required to be bonded includes baths and exposed metal pipes, sinks, taps, tanks, and radiators and, where practicable, accessible structural metalwork

Those far reaching changes, issued on 31st March 1981, are still being felt today with designers and specifiers still implementing the requirements for supplementary equipotential bonding from the 15th Edition. Much of the confusion can be attributed to the note of Regulation 413-7 which required the bonding of all metallic items, essentially, those within the designated equipotential zone. This led to the installation of supplementary equipotential bonding of general metallic items such as baths, ceiling grids, hand rails, kitchen sinks, radiators, pipework at boilers, etc. Thankfully, we have moved on from this general concept.

HTH

 

[Sidewinder]

PaulThe change from the 14th to the 15th Edition of the IEE Wiring Regulations in 1981 created a big upheaval in the electrical installation industry as many new concepts were introduced and many existing practices were expanded or enhanced - one of those being supplementary equipotential bonding. To a great extent, the 15th Edition was based on CENELEC harmonised documents (HDs) (more so now with the introduction of the 17th Edition).

I knew this as I now have both the '76 version of the 14th & the 81 version of the 15th.

I recognised the similarity in the 15th to the subsequent regs.

I don't have a copy of the CENELEC doc of the era unfortunately.

HD 384.4.41 was the basis for Chapter 41 of the 15th Edition - Protection against electric shock, which had requirements for supplementary equipotential bonding in Regulation 413-7, reproduced here:

413-7 Within the zone formed by the main equipotential bonding, local supplementary equipotential bonding connections shall be made to metal parts, to maintain the equipotential zone, where those parts -

(i) are extraneous conductive parts, and

(ii) are simultaneously accessible with exposed conductive parts or other extraneous conductive parts, and

(iii) are not electrically connected to the main equipotential bonding by permanent and reliable metal-to-metal joints of negligible impedance. NOTE - Where local equipotential bonding is provided in accordance with Regulation 413-7, metalwork which may be required to be bonded includes baths and exposed metal pipes, sinks, taps, tanks, and radiators and, where practicable, accessible structural metalwork

This is the reg no. I was looking for.

I had found 471-22 for the special provisions and exceptions, but had not yet found this reg group.

Thank you.

Those far reaching changes, issued on 31st March 1981, are still being felt today with designers and specifiers still implementing the requirements for supplementary equipotential bonding from the 15th Edition. Much of the confusion can be attributed to the note of Regulation 413-7 which required the bonding of all metallic items, essentially, those within the designated equipotential zone. This led to the installation of supplementary equipotential bonding of general metallic items such as baths, ceiling grids, hand rails, kitchen sinks, radiators, pipework at boilers, etc. Thankfully, we have moved on from this general concept.

Thus, IMHO it is still the ambiguity that required all this bonding!

We were on the start of the slippery slope.

I had the language differences explained to me once, but I can't remember it, the thing that does stick is something like the difference between Anglo-Saxon & Romanic or something, I'll rack my brains and try to find out what was discussed!

HTH

My RED above, and yes thanks it does help as I had not tracked down that reg in the book I have, now I can see where it all comes in.

There is a significant step change between '76 & '81!

 

[Voltimax]

The contractor I am up against issues single page EIC's FFS!

Sidewinder, Napit have a single page EIC just for the addition of a new circuit, which also doubles as a minor works, personally I don't use them. Is this what you refer to here per chance? or are you talking about something, he's thrown together himself?

 

[Sidewinder]

Volti,

The work he had done was more than a minor works cert really.

Also as far as I know he is not in any scam.

Edit:

Volti, I'm not at all familiar with (i.e. have never seen) the single page NAPIT EIC/MWC, would that be suitable for 3ph industrial kit?