18th Edition Bonding requirements

[mattg4321]

Was talking about this with a couple of guys on site earlier and differing opinions were had. It seems the line quoted below has introduced some confusion.

"Metallic pipes entering the building having an insulating section at their point of entry need not be connected to the protective equipotential bonding (Regulation 411.3.1.2)."

Example 1. Some were of the thinking that for example an incoming iron water pipe that somewhere just above floor level had say a metre of plastic pipework before continuing in copper would never need bonding as it has an insulating section. Some were of the thinking you should test the pipework above and/or below the insulating section to see if it is extraneous.

Example 2. Some were of the thinking that any utility supply service that enters the building in plastic will never need bonding and some thought the internal pipework should be tested to see if it is extraneous.

What say you forum? I have my own thoughts I shall keep to myself for now...

 

[Harry_P]

Was talking about this with a couple of guys on site earlier and differing opinions were had. It seems the line quoted below has introduced some confusion.

"Metallic pipes entering the building having an insulating section at their point of entry need not be connected to the protective equipotential bonding (Regulation 411.3.1.2)."

Example 1. Some were of the thinking that for example an incoming iron water pipe that somewhere just above floor level had say a metre of plastic pipework before continuing in copper would never need bonding as it has an insulating section. Some were of the thinking you should test the pipework above and/or below the insulating section to see if it is extraneous.

Example 2. Some were of the thinking that any utility supply service that enters the building in plastic will never need bonding and some thought the internal pipework should be tested to see if it is extraneous.

What say you forum? I have my own thoughts I shall keep to myself for now...

I think its another case of people making something complicated when it could be so simple. I interpret that reg as 'if the metallic pipes entering the building have gone into plastic pipe at the point of entry then it is pointless bonding because the electrical connection wont get past the plasic because plastic is not a good conductor of electricity.
Ps , is the extraneous pipe 'liable to introduce a potential '? Definitely not if it's subsequently gone into plastic

 

[Deleted member 26818]

This is not an 18th edition bonding requirement.
This is just an explanation of what everyone should have been doing all along.

 

[mattg4321]

This is not an 18th edition bonding requirement.
This is just an explanation of what everyone should have been doing all along.

You try telling that to a meter fitter when you haven't bonded anything!

Also, it has changed things slightly in that you would still be required to bond the incoming iron pipework where it enters the property below the insulating section in 17th edition regs.

Are you in agreement that if there is an insulating section there is NEVER a need to bond and no need for any testing then?

 

[Harry_P]

You try telling that to a meter fitter when you haven't bonded anything!

Also, it has changed things slightly in that you would still be required to bond the incoming iron pipework where it enters the property below the insulating section in 17th edition regs.

Are you in agreement that if there is an insulating section there is NEVER a need to bond and no need for any testing then?

To be fair I would only explain it to a meter fitter if he was paying me to do the job,otherwise he would be told to worry about his own job and leave me to worry about mine. The only time I get involved in debates about electrics with non electricians is if it's with the bill payer and I am on day rate,then I don't mind talking all day

 

[johnduffell]

insulating section at their point of entry

it has changed things slightly in that you would still be required to bond the incoming iron pipework where it enters the property below the insulating section in 17th edition regs.

if there's a metal pipe below, then the insulating section isn't at the point of entry. I'm sure everyone has their limits on how far from the point of entry is close enough, but if the water supply comes in 6 inches of metal at elbow height next to the washing machine on a TN-C-S that's a bit different from 5 metres of lead pipe lying in the dirt under the suspended floor on a TT. Use common sense I suppose.
Personally I just think the clarification is to wastage of copper by people who don't know what extraneous is.

Some were of the thinking you should test the pipework above and/or below the insulating section to see if it is extraneous.

you should test anything that may be extraneous same as always, not just the common services. this reg doesn't do anything special

how about if you have incoming in plastic then goes around the house in copper and tees off to an outbuilding underground still in copper. You'd test after the insulating section and discover it appears to be extraneous, but the incoming water supply still doesn't need bonding, but the outgoing supply to the shed does. so bonding the incoming supply after the insulating section would be non compliant with the regs.

 

[Nigel]

You try telling that to a meter fitter when you haven't bonded anything!

Also, it has changed things slightly in that you would still be required to bond the incoming iron pipework where it enters the property below the insulating section in 17th edition regs.

Are you in agreement that if there is an insulating section there is NEVER a need to bond and no need for any testing then?

No as this insulating section would then be after the point of entry and therfor the pipe before the insulating section would need bonding.

 

[Wilko]

Many new supplies have plastic for gas and water, but that hasn't stopped folks from bonding the copper on the house side of the meter. I'm thinking it's not breaking the regs to bond in this case and it may prevent future issues. But always happy to learn .

 

[Ian1981]

Many new supplies have plastic for gas and water, but that hasn't stopped folks from bonding the copper on the house side of the meter. I'm thinking it's not breaking the regs to bond in this case and it may prevent future issues. But always happy to learn .

You should limit any pipe work that’s connected to earth that doesn’t need to be as it introduces a potential that need never had existed.
Gas pipes will be connected to earth via the cpc connecting to the boiler manifold anyway but unnecessary pipe work bonded should be avoided

 

[Flanders]

The key word is insulating section not insulated section , water can still carry electricity so I would always test to confirm if it needs bonding.

 

[Ian1981]

The key word is insulating section not insulated section , water can still carry electricity so I would always test to confirm if it needs bonding.

Water is actually a poor conductor of electricity
In this instance I would go with what bs 7671 tells us about this particular subject.

 

[Flanders]

Water is actually a poor conductor of electricity
In this instance I would go with what bs 7671 tells us about this particular subject.

Yes I agree with that but if the plastic part was very short for example a plastic coupler the electric could slip through , I think there is a calculation for this.

 

[Midwest]

You should limit any pipe work that’s connected to earth that doesn’t need to be as it introduces a potential that need never had existed.
Gas pipes will be connected to earth via the cpc connecting to the boiler manifold anyway but unnecessary pipe work bonded should be avoided

Personally I can't see any change in the old gambit, if its metal bond it approach.

I've moved into a new build, and both services are plastic. Haven't verified whats happened to the water, but the gas has been bonded, although the copper pipe goes from the meter box 4m to the boiler in the garage. Large domestic house basher, who must have loads of HNC etc etc designers/engineers with more initials after their name than Phil the Greek, but still have the bond it approach.

 

[Ian1981]

Personally I can't see any change in the old gambit, if its metal bond it approach.

I've moved into a new build, and both services are plastic. Haven't verified whats happened to the water, but the gas has been bonded, although the copper pipe goes from the meter box 4m to the boiler in the garage. Large domestic house basher, who must have loads of HNC etc etc designers/engineers with more initials after their name than Phil the Greek, but still have the bond it approach.

I’ve done the old 500v IR test approach onto the piece of metal(gas) and the MET on my new build.
Got a reading of around 15-20Mohms.

 

[Wilko]

I’ve done the old 500v IR test approach onto the piece of metal(gas) and the MET on my new build. Got a reading of around 15-20Mohms.

Hi - how can this be?
To your point earlier - shouldn't the boiler itself be earthed and gas pipework after the meter is copper ... (?)

 

[Ian1981]

Hi - how can this be?
To your point earlier - shouldn't the boiler itself be earthed and gas pipework after the meter is copper ... (?)

Remove the parallel paths

 

[Wilko]

Dohh - should've seen that one coming .

 

[johnduffell]

Remove the parallel paths

Picking hairs now but you can't remove them all without disconnecting the downstream connection of the water/gas
How about if the boiler is in, and the gas is extraneous but not the water, you wouldn't be able to tell which without breaking into the pipe work.
Same goes if neither are but there's something else extraneous that you don't know about that's connected to the internal pipework elsewhere.

 

[Ian1981]

Water is plastic
There’s nothing else extraneous having worked and still do in new builds

 

[Flanders]

Hi - how can this be?
To your point earlier - shouldn't the boiler itself be earthed and gas pipework after the meter is copper ... (?)

If you disconect the main earth cable from the CU the MET and do the test from MET to the gas pipe and it is not extraneous then you would get a high Meg ohm reading

Edit Ian beat me to it

 

[johnduffell]

Water is plastic
There’s nothing else extraneous having worked and still do in new builds

Yeah sorry i meant in general, if it's a new build you know what you're getting!

 

[Silly Sausage]

Had a nosey round a house once, plastic water pipe hanging in a big arc from cellar ceiling joists, with a brass stock cock half way along, with a nice juicy 10mm G/Y cable clamped to it, also hanging in a big arc, back to the CU.

Clueless!

 

[johnduffell]

If you disconect the main earth cable from the CU the MET and do the test from MET to the gas pipe and it is not extraneous then you would get a high Meg ohm reading

You'd also need to remove any bonding from the met otherwise you'd likely get a path between the water bond and the gas pipe

 

[Flanders]

You'd also need to remove any bonding from the met otherwise you'd likely get a path between the water bond and the gas pipe

Yes your correct . Sorry did not explain fully as in most casees the bonding is connected at the CU not the MET so would of been disconnected in my scenario

 

[Pete999]

Had a nosey round a house once, plastic water pipe hanging in a big arc from cellar ceiling joists, with a brass stock cock half way along, with a nice juicy 10mm G/Y cable clamped to it, also hanging in a big arc, back to the CU.

Clueless!

Makes a mockery of SOME of the SCHEME firms doing new builds doesn't it Archy? sometimes wonder why bother, doing an Apprenticeship, so who is to blame? Certsure? needs sorting PDQ

 

[Ian1981]

Makes a mockery of SOME of the SCHEME firms doing new builds doesn't it Archy? sometimes wonder why bother, doing an Apprenticeship, so who is to blame? Certsure? needs sorting PDQ

I find it’s a lack of supervision/understanding as when we are younger we tend not to care as much.
That is what the QS position should be about, to supervise and instruct, tho it’s often abused.

 

[Pete999]

I find it’s a lack of supervision/understanding as when we are younger we tend not to care as much.
That is what the QS position should be about, to supervise and instruct, tho it’s often abused.

Dissagree with you on this one Ian, yes the inspector should have picked it up, but the Bloke that did the install, was /is at fault, no excuses for this cock up Sparky doing it needs educating with his P45. And I use the words Sparky with trepidation, more than likely been working with someone for a few weeks, knows it all, bond the water pipe jobs a good un, seen it many times. No offence meant in my disagreement.

 

[Ian1981]

Dissagree Ian no excuses for this cock up Sparky doing it needs educating with his cards.

Not like you to dismiss anyone’s opinions is it?

 

[Pete999]

Not like you to dismiss anyone’s opinions is it?

I'm not dismissing the opinion Ian, just disagreeing with it, your opinion is a valid one, but the faults lies not initially with the QS but with the "Electrician?" in the first instance, but in hindsight the QS should have picked it up, if he ever checked the bonding that is, I have a Friend who was a QS, and he assures me time for detailed inspections are governed by Bosses/Managers, with no interest in quality, more concerned with quantity, please don't take my response so lightly, it's a sticky issues with new builds and unskilled operatives, you must know how it works!

 

[westward10]

Sounds like the old broken record is on again.

 

[Rpa07]

Had a nosey round a house once, plastic water pipe hanging in a big arc from cellar ceiling joists, with a brass stock cock half way along, with a nice juicy 10mm G/Y cable clamped to it, also hanging in a big arc, back to the CU.

Clueless!

And why do we not have a photo - you know the forum rules . . . .
If we can laugh at someone else’s stupidity - We will!

 

[mattg4321]

I'm struggling to see what the point of the extra sentence in the new regs is?

It's changed nothing practical. All it's done is muddy the waters. How many people are going to take it as: 'If the water/gas comes into the building in plastic, then I won't carry out bonding'?

 

[Wilko]

And why do we not have a photo - you know the forum rules . . . .
If we can laugh at someone else’s stupidity - We will!

Here's something similar I found a while back. The plumbing in the agricultural building had been changed to plastic, but the label says don't remove, so they didn't
Edit - pipe and clamp was sitting on the floor but still attached to the MET with that g/y. Unfortunately I'd tidied it up before the pic, sorry.

 

[Pete999]

Sounds like the old broken record is on again.

Not worth responding to.

 

[westward10]

Not worth responding to.

You just did

 

[Pete999]

You just did

Would be rude not to respond to an insult like that wouldn't it Wesward, what a pity there is not a way to ignore a Moderator.

 

[westward10]

Was only in a bit of jest Pete no bad intentions.

 

[GMES]

And yet again post removed by a certain mod without explaining why. Have the decency to say why it’s deleted even if it’s for your own adgenda

What do you mean by a certain Mod, I removed your reply yet had nothing to do with the previous exchange between pete and westy.
Your comment was removed for two reasons and that was because it did not help the situation and it is none of your concern.
It was an exchange between two grown men / members.
I'm pretty sure they are big enough and ugly enough to resolve whatever it was without your intervention.

 

[camerabloke]

It’s a free country ain’t it

 

[camerabloke]

And why no heads up on why it was removed until I complained