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Evans Electric

Bonding ..again !

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binky

had a house like that, plastic pipe joins everywhere, at least plumbers tend to use hepco through out these days apart from gas.

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Sidewinder

OK, as far as the gas "Regs" go, and that is the legal "regs" not some trumped up British Standard.

The Gas Safety Installation  Use Regulations, require bonding to be installed in accordance with BS 7671.

That's that.

 

The requirement is to bond, extraneous-conductive-parts where they enter the equipotential zone, if they bring a potential into that zone, normally an earth potential, then they need to be bonded.

 

You can apply the 23k test, but that would simply show that it needs bonding as the impedance would be <23k.

 

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ProDave
31 minutes ago, Sidewinder said:

OK, as far as the gas "Regs" go, and that is the legal "regs" not some trumped up British Standard.

The Gas Safety Installation  Use Regulations, require bonding to be installed in accordance with BS 7671.

That's that.

 

The requirement is to bond, extraneous-conductive-parts where they enter the equipotential zone, if they bring a potential into that zone, normally an earth potential, then they need to be bonded.

 

You can apply the 23k test, but that would simply show that it needs bonding as the impedance would be <23k.

 

Someone needs to tell the gas fitters around here about that then.

 

e.g the argument I had with the gas fitter who would not issue a landlords gas certificate because "the gas was not bonded"  The meter was at the front of the house. The gas pipe ran all the way round on the outside of the building and entered at the back, where it was bonded. But the gas fitter insisted it was bonded within 600mm of the gas meter.

Edited by ProDave

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Sidewinder
31 minutes ago, ProDave said:

Someone needs to tell the gas fitters around here about that then.

 

e.g the argument I had with the gas fitter who would not issue a landlords gas certificate because "the gas was not bonded"  The meter was at the front of the house. The gas pipe ran all the way round on the outside of the building and entered at the back, where it was bonded. But the gas fitter insisted it was bonded within 600mm of the gas meter.

Dave,

Just download a copy of the GSIUR and show him, it's law, so it's free, then go on the HSE website, and download the HSE ACOP L56, it's in both of them, that'll shut 'em up.

I used them in conjunction with as it happens the NICEIC pocket guide to bonding, which is quite useful, and is downloadable to shut up a British Gas guy, he was quite humbled when he found out he had been taught wrong, and had been wrong for many years!

 

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sprocketflup

Within 600mm of where it enters the property/zone then. The gas regs ask for within 300mm don't they?

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Jono Pashley
3 hours ago, sprocketflup said:

Within 600mm of where it enters the property/zone then. The gas regs ask for within 300mm don't they?

Gas Regs defer to BS7671 so no

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Sidewinder

Right here we go.

The LAW regarding gas is "The Gas Safety (Installation & Use) Regulations 1998".

These are UK Statutory Instrument 1998 No 2451.

Located here:

http://www.legislation.gov.uk/uksi/1998/2451/contents/made

This is attached to this post.

These have been amended just last year by the following:

The Gas Safety (Installation and Use) (Amendment) Regulations 2018

This is UK Statutory Instrument 2018 No 0139.

This is attached to this post in PDF form, it was downloaded from here:

http://www.legislation.gov.uk/uksi/2018/139/pdfs/uksi_20180139_en.pdf

Earlier today.

 

OK the requirement for bonding under the gas requirements comes from Regulation 18 (2):

PART D

INSTALLATION PIPEWORK

Safe use of pipes 18.—

(2) Any person who connects any installation pipework to a primary meter shall, in any case where electrical equipotential bonding may be necessary, inform the responsible person that such bonding should be carried out by a competent person.

 

You are welcome to search the LAW for bond, and you will find that this is the ONLY reference to a permanent bond, Regulation 10 requires temporary bonding when work is undertaken to ensure electrical continuity of pipework.

 

The next relevant document is the HSE ACoP, L56.

This was updated in 2018 to reflect the change in law.

It is available here:

http://www.hse.gov.uk/pubns/priced/l56.pdf

It is also attached to the post.

Here you will find guidance on Regulation 10 temporary bond during works and regulation 18 above.

If you refer to paragraph 200 you will see it says:

200 The location and routing of installation pipework should take into account the potential risk (eg of corrosion damage) posed by the other building services, equipment and features specified in regulation 18(1), for instance by providing adequate separation. Pipework installation and equipotential bonding should be carried out to the appropriate standard.

Then paragraphs 201 & 202 discuss this further:

201 Main equipotential bonding (MEB, sometimes known as ‘electrical cross bonding’) is the connection between the consumer earth point and the gas installation pipe. The purpose is to create a zone (eg within a dwelling), including the area occupied by the gas installation pipework, within which acceptable voltage differences are maintained to avoid the risk of electric shock.


202 The person who installs a section of pipework which connects with the primary meter or emergency control, whether or not the meter or control has yet been fitted, must inform the responsible person for the premises (builder, owner or occupier) of the possible need for MEB where such a requirement did not exist before the work was undertaken. Such bonding should be carried out by a competent person (see regulation 3, Qualification and supervision, for details on training and competence). The advice should be in writing. Although the regulation applies only when new systems are installed and existing ones are modified, similar action needs to be taken if an engineer notices an apparent defect in bonding in other circumstances, eg during maintenance checks (this applies to both main or supplementary equipotential bonding – see also paragraph 206).

 

Because this must be done, then paragraph 203 refers to new works, because the law says it must be done, so we should NEVER find it missing.

203 Main equipotential bonding is most commonly required where:
(a) gas pipework is installed in new premises; or
(b) gas pipework is first installed in existing premises.

 

204 to 207 finish this off.

204 The regulation is directed at the 600 mm (approximate) length of installation pipework at the outlet of the domestic meter installation which is the recommended location of any main equipotential bond in the appropriate standard.
205 The requirements for main equipotential bonding are more strict for certain types of electrical supply to premises (eg those supplies from protective multiple earth (PME) systems – most new electrical supplies will be from such systems). A gas engineer may not be competent to make the necessary judgement, in which case the responsible person needs to be informed of this fact and any further action left to them.
206 Regulation 18(2) does not apply to the installation of a meter. In addition to main bonding, supplementary equipotential pipework bonding may be necessary in locations of increased electric shock risk, eg bathrooms. In such cases, a competent electrician should be consulted.
207 In many commercial and other large sites where gas and electric meters may be remotely located, the bonding is not always possible within a 600 mm distance.

A competent electrician needs to consider what action is necessary in these cases.

 

The HSE ACOP states that a gas "engineer" may not be competent to define the requirements of bonding and that a competent electrician is required to do this.

 

Regulation 3 is mentioned in the above paragraphs with regard to competence, it relates to gas competence, not electrical.

Feel free to check.

 

HSE guidance on the law, in paragraph 200 requires pipework & bonding to be installed in accordance with the relevant standard.

I can't attach those as they are copyright BSI, however, they are:

Bonding: BS 7671

Gas Pipework: BS6891, "Specification for the installation and maintenance of low pressure gasp installation pipework of up to 35mm (R11/4) on premises

In BS 6891, Section 2 is Normative References, Normative means that they must be read in conjunction with this standard.  BS 7671 is listed therein.

Thus, compliance with BS 6891 requires compliance with BS 7671, and the GSIUR ACOP requires that these standards are followed in the guidance paragraphs.

Remember that ACOPS have a special section in the Health and Safety at Work etc Act 1974, they have special legal status.

 

Section 8 in BS 6891 refers to temporary bonds which do not concern us, until we get to 8.4.3, on:

 

8.4.3 Main protective bonding conductor
8.4.3.1 A gas installation within a property with an electrical supply shall have a main protective bonding conductor connecting the pipework to the electrical installation’s main earth terminal, as specified in BS 7671.
COMMENTARY ON 8.4.3.1
The purpose of protective bonding is to create a zone in which voltage differences
through differing earth potentials are eliminated, and therefore hazards from electric shocks are minimized. This is achieved by connecting separate conductive components, such as the various metallic building services and structural steelwork, together with a main protective bonding conductor at the main earth terminal.
It is possible for stray currents to be transmitted through the gas pipework.
Therefore, to avoid electric shock or a spark which could ignite the gas, it is important to maintain electrical continuity in the pipework at all times.
8.4.3.2 The main protective bonding conductor (main equipotential bonding connection) shall be connected to the gas consumer’s fixed rigid pipework on the outlet of any primary meter installation, if fitted:
a) as near as is practicable to the point of entry into the premises;
b) before any branch in the pipework;
c) in a position where it is accessible and can be visually inspected and fitted with a warning label stating “Safety electrical connection. Do not remove.”;
and
d) by a mechanically and electrically sound connection which is not subject to corrosion.
The main protective bonding conductor (main equipotential bonding connection) shall not be directly connected to any pliable corrugated (stainless-steel) tube or pliable connectors from the outlet of the primary meter installation.
COMMENTARY ON 8.4.3.2
The main protective bonding conductor on the gas pipework should be made using cable with minimum cross-sectional area of 10 mm2 cable with green and yellow insulation, construction reference 6491X conforming to BS 6004.
For internal meters, for verification purposes the bonding connection should be within 600 mm of the meter outlet union.
For meters in outside meter boxes/compartments, the bonding connection should preferably be inside the premises and within 600 mm of the point of entry of the pipework into the premises.
Alternatively, the connection can be made within the box/compartment, but it is essential that the bonding cable does not interfere with the integrity of the box/compartment and the sealing of any sleeve (see Figure 8).
For guidance on equipotential bonding in multi-dwelling buildings see IGEM/GM/5 [26].
When relocating a meter, an existing main protective bond conductor might be satisfactory as found, or it might need to be altered. Where the bonding conductor requires altering, any alterations should be carried out by an electrically competent person, and inspected and tested in accordance with BS 7671. The bonding connection may be considered satisfactory if the requirements of 8.4.3.1 are met.

 

Now a few things come out of that, that the bond needs to be INSIDE the premises and it is down to an electrically competent person to decide, and that this needs to be in accordance with BS 7671.

 

It seems to me that the gas fitters need to shut up and learn what is required.

 

QED I think?

l56-GSIUR2018.pdf

uksi_19982451 GS(I&U)R.pdf

uksi_20180139_en GS(I&U)R-Amd-2018.pdf

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sprocketflup
14 hours ago, Jono Pashley said:

Gas Regs defer to BS7671 so no

Yeah, we think that, I'm yet to meet a gas fitter that agrees!

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Sidewinder
58 minutes ago, sprocketflup said:

Yeah, we think that, I'm yet to meet a gas fitter that agrees!

Well tell them that they don’t have a clue, the evidence you need is above.

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Jono Pashley
2 hours ago, sprocketflup said:

Yeah, we think that, I'm yet to meet a gas fitter that agrees!

There is no think its in black and white. If gas chimp doesnt like it he can ask an appropriate adult to read the gas regs too him

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Rob_the_rich

Refer them to latest Gas Industry Unsafe Situations Procedure Here (specifically to 3.3.2) ie There is a duty to inform the responsible person in writing. We were advised in training recently to preferably get a signature to prove they received the bonding notice. That is it though, it is not "At Risk" nor "Immediately Dangerous" (there is no "Not to current standards" classification any more as can be seen in the above document)

 

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Tony S

Copper pipe CSA

 

15mm  = 18.3mm²

22mm  = 27.2mm²

28mm = 46.8mm²

 

Based on standard 0.4mm wall thickness for pipes up to 28mm

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Rob_the_rich
2 hours ago, Tony S said:

 

Based on standard 0.4mm wall thickness for pipes up to 28mm

Looking at this document the old table X pipes had walls 0.7mm for 15mm and 0.9mm for 22 and 28mm

I get CSA of 15mm at 31.4mm2

22mm at 59.6mm2

and 28mm at 76.6mm2

😃

 

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Tony S
38 minutes ago, Rob_the_rich said:

Looking at this document the old table X pipes had walls 0.7mm for 15mm and 0.9mm for 22 and 28mm

I get CSA of 15mm at 31.4mm2

22mm at 59.6mm2

and 28mm at 76.6mm2

😃

 

 

I stand corrected, but the CSA of contiguous copper pipe is far higher than the CSA of BS7671 requirements for gas bonding. There is also the matter of copper purity and conductivity, this is negligible.

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binky

The ultimate argument for considering the pipe a far better condcutor than any ruddy bond  especially where the pipe pops up and down through the floor.

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Tony S

If the pipe passes through a concrete slab it could be construed as an Ufer electrode. Where does that leave BS7671?

 

OK, I know, bond each end! :kermit:

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binky

Writing a risk assessment! 

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Geoff1946
9 hours ago, Tony S said:

If the pipe passes through a concrete slab it could be construed as an Ufer electrode. Where does that leave BS7671?

 

Surely unprotected copper pipe shouldn't be directly in concrete? 

 

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Tony S

Why not?

 

Read up on Ufer earthing systems.

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Geoff1946

I was thinking of corrosion of the pipe by chemicals in the concrete. I know that copper is used for earthing electrodes but then a bit of corrosion won't matter. In thin walled water or gas pipe it could be a different story.  When I've done plumbing work I've always sleeved pipes passing through masonry with the next size up. to bury in plaster I've always taped it. I can't remember now who told me to; perhaps it's over cautious.

Edited by Geoff1946

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Sidney

Cement will corrode copper pipe, last lot I looked at had been in around 50 years before it failed and flooded the kitchen.

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Tony S

The worse place for corrosion is where the copper enters or exits the slab, a lick of bitumen at these points gets around that. A too strong mix is another corrosion problem, casting a slab doesn’t need a great deal of cement and lime.

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Evans Electric
3 hours ago, Sidney said:

Cement will corrode copper pipe, last lot I looked at had been in around 50 years before it failed and flooded the kitchen.

Yes ,  a colleague of ours was called to look at a load of damp on a screeded floor  extension .       The heating pipes had been laid across the slab and screeded over but without any taping  .  I think they'd been in about 3 years  before  being eaten away by the cement / lime  whatever .  

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phil d
12 hours ago, Evans Electric said:

Yes ,  a colleague of ours was called to look at a load of damp on a screeded floor  extension .       The heating pipes had been laid across the slab and screeded over but without any taping  .  I think they'd been in about 3 years  before  being eaten away by the cement / lime  whatever .  

Re the above, my daughter-in-law's uncle bought a large bungalow in a posh area on the outskirts of Manchester, all the heating pipes were run in the concrete floor, over the years they began to corrode however he was unaware of this until they began to leak and cause problems with damp.

He had a local plumbing firm out and they removed a section, it had failed over about 6 inches at the point they dug it up and was likely to be like this all over the house. He rang his insurance and they said they needed a quote for ripping out the whole system, and replacing it exactly as it was done originally! Nobody would even quote for the job, as, not only did it not comply with modern regs, it would only fail in the same way in the future.

It was a stalemate, the insurers wouldn't pay out without the quote and none of the plumbing firms he rang would quote for a job knowing they'd never get it, this went on for weeks, eventually, he rang me about another matter and happened to mention this problem. I went and had a look at it, every floor would need digging up, major damage to the decor and it would take about 3 weeks.No problems I'll sort it, so away I went, I wrote a report on the job, the reason the pipes had failed, the amount of work needed to replace all the pipework like for like, and warned them that doing it the same way was only creating problems for the future. I also drew up a design to refeed everything via the loft, quicker, easier and a lot cheaper.

I put a quote in for the original job of somewhere around £10K, with the alternative coming in at around half that, including making good the damage caused by the original faults. Surprisingly enough they didn't like the quote to reinstate as was and went for the cheaper quote, he then got a local plumber to do the work for a bit less, so he was happy, as for me, well I didn't even get a drink out of it. Lesson learned 

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Evans Electric
8 hours ago, phil d said:

as for me, well I didn't even get a drink out of it. Lesson learned 

Ah yes  !  How many times does that happen ?  

 

A Birmingham sparks who was a good friend used to fall for that one .  He,s no longer with us unfortunately . Living in a "posh" area  where sex was what the coal came in , most of his customers were "posh"  but they 'd have him running around for them ,  matching paint etc   ( He did decorating  & plumbing)   .  One story was  fitting two lights each side of a mirror ..." Don't like them  , you'll have to get something else "   He was running around bringing catalogues ,  booking  samples out , taking them back  etc etc .

             

The next thing , he wasn't making any money , falling behind with bills .    Being a perfectionist , his decorating didn't pay , he would fetch it all off the next day  as there was a minor thing , he couldn't live with it .  To you and me it was really good work but no , off it came again .  

Wouldn't listen .  

 

Remember him asking  how much we charge for one  socket , domestic. Those days it was £40 , basically spur off to one twin socket .  

I hate them he says ,  how do you make any money ?  

A basic job , I say , is perhaps a couple of boards up and mini trunk down the wall .   

 

Unfortunately his basic was  chasing out the cable drop , chasing a box in , re-plastering  , then back a week later to expertly re- stick the carefully peeled back wallpaper  so you wouldn't know it had been done .       A top class job which left him about £100 out of pocket . 

 

I'm not criticising him , it was just the way he was ...when he worked with us  he was suddenly  paying the bills again ...but it takes all sorts ..  a workmate  for forty years  on & off  ... leukaemia   got him two years ago  .   

RIP  Mate . 

Edited by Evans Electric

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