Supplementary Equipotential Bonding Q

[John D v2.0]

The regulation about the siting of main bonding is totally confused/confusing, seemingly written by someone who had no idea about the concept and purpose of main bonding

Yes not to mention that you have to bond gas just after the meter, regardless of whether the meter is inside or out and where the conductive part entered

However, I think you're making the same mistake as bernard.

I'm not making any mistake, that was my response to back up your point that whoever wrote the regs in that area was generally confused.
I think the bonding should be fitted where the service enters the house, ie introduces a potential, not elsewhere

 

[John D v2.0]

Oh - I realise you mean that when external the point of entry is after the meter - but

that would be correct IF, as John said, it IS an extraneous-c-p.

Actually I mean that the bonding should be irrelevant of where the meter is, it should be where the service enters.
Never mind all the talk of within X mm and before the first tee. If the pipe Tees outside and enters in two places I'd be happy to call them both ecps and bond separately.
I think the gas meter rule is just to ensure its bombed exactly once.

 

[EFLImpudence]

It would not really matter except the regulation specifically mentions an insulating section which completely changes the situation.

 

[EFLImpudence]

Actually I mean that the bonding should be irrelevant of where the meter is, it should be where the service enters.

That is correct.

Never mind all the talk of within X mm and before the first tee. If the pipe Tees outside and enters in two places I'd be happy to call them both ecps and bond separately.

Well, if they both ARE, then yes.

I think the gas meter rule is just to ensure its bombed exactly once.

I think, as John said again, whoever wrote it should not have.

 

[JohnW2]

I'm not making any mistake, that was my response to back up your point that whoever wrote the regs in that area was generally confused. I think the bonding should be fitted where the service enters the house, ie introduces a potential, not elsewhere

Yes, but only IF it actually is an extraneous-c-p.

The most crazy thing about that reg is that, if a metal pipe enters the building and then goes through a meter (which does not provide electrical continuity), adhering to that regulation would leave the bit of pipe (upstream of the meter) which should be bonded without a bond, and would bond something (downstream of the meter) that didn't need bonding!

Kind Regards, John

 

[ban-all-sheds]

Or water (if there is a meter there). However, I think you're making the same mistake as bernard. That crazy regulation (which, IMO, is probably best ignored - whatever BAS might say about ignoring regulations!) about 'where one should bond' only applies IF main bonding is required - and there is never a requirement to main bond something which is not an extraneous-c-p.

The regulation is not "crazy", as it does not apply when an incoming service is not an e-c-p. See 411.3.2

 

[JohnW2]

The regulation is not "crazy", as it does not apply when an incoming service is not an e-c-p. See 411.3.2

I think you'll find that I've said that a few times in this thread (and others).

However (as per my post immediately before yours), what IS, in my opinion, crazy is that if there IS an extraneous-c-p entering the building which travels to a meter (which does not provide electrical continuity), then following the regulation results in one not bonding the bit of pipe (upstream of the meter) that theoretically should be bonded, but bonding the pipe (downstream of the {insulating} meter) that does not need to be bonded.

Kind Regards, John

 

[ban-all-sheds]

No it doesn't, because the pipe downstream of the meter is not an e-c-p, and therefore does not have a MPB connection.

 

[JohnW2]

No it doesn't, because the pipe downstream of the meter is not an e-c-p, and therefore does not have a MPB connection.

Agreed - but, as I said, in the scenario I described, the pipework upstream of the meter IS an extraneous-c-p, and therefore should have main bonding - but would not get it if one followed the regulation in question.

Kind Regards, John

 

[bernardgreen]

Just to muddy the water......

If the gas pipe work in the house only supplies appliances which do not have any electrical connections then wouldn't connecting the gas pipes to the MET ( bonding or earthing ) be similar to connecting metal stud work to the MET. The gas pipes, like the metal stud work are not part of the electrical installation until they are connected to the MET.

 

[John D v2.0]

Just to muddy the water......

If the gas pipe work in the house only supplies appliances which do not have any electrical connections then wouldn't connecting the gas pipes to the MET ( bonding or earthing ) be similar to connecting metal stud work to the MET. The gas pipes, like the metal stud work are not part of the electrical installation until they are connected to the MET.

I don't think that muddies the water, I think that is the whole point, that it's not an ECP after the insulating section. Additionally, the discussion is that it is an ECP before that section.

 

[bernardgreen]

that it's not an ECP after the insulating section.

What is the situation if there is no insulating ( or isolating ) section. Such as a water pipe supplying only a couple of taps and no other appliance ( ie no water heater of any sort )

 

[John D v2.0]

What is the situation if there is no insulating ( or isolating ) section. Such as a water pipe supplying only a couple of taps and no other appliance ( ie no water heater of any sort )

Well then it would be an ECP as it might introduce earth potential from outside, so needs bonding.

 

[bernardgreen]

so needs bonding.

OK but that means it is also Earthed, so we now have taps that are earthed ( and possibly the stainless steel sink they are fitted in ) thus making them "hazardous" to anyone touching them while also in contact with an item that, due to a fault in that item, is Live.

If the taps were not earthed then they could not enable current to flow when touched. We are not supposed to earth or bond metal sinks to reduce the risk of a shock, yet they can be connected to earth via the bonds fitted to the incoming pipe work to prevent the extraneous "Earth" potential being imported into the building via the water supply pipe.

 

[John D v2.0]

Not sure what your point is, but if it's that ecps are a bad thing and should be avoided then I'd agree. The only reason we bond is because it's the only reasonable thing to do given an existing ecp. Getting rid altogether is better.