Gas bonding regulations
- Thread starter AndyPRK
- Start date
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We are NOT arguing. We are telling you what is required electrically to ensure it is safe - no matter what anyone writes.
That statenent is correct as far as it goes, although I don't know how it affects the gas installation.
Perhaps the wording on your form should just ask if the bonding is present rather than satisfactory.
However, more recently some supplies have an insulating section which electrically separates the incoming pipe from the meter and consumer's pipework. In such circumstances it is the incoming pipe that should be bonded otherwise you may as well not bother. The electrical regulations have just corrected the misinformation it has been stating for years - I don't know why they have been wrong for so long.
With an insulating section and bonding on the consumer's side, nothing is achieved. It still might not be safe for you to touch both the incoming pipe and meter even with the meter still connected.
Either way (correctly bonded or not), you should, and I presume you do, when disconnecting a meter, temporarily bond the incoming pipe to the consumer's pipe.
All this, of course, presumes the supply pipe IS an extraneous-conductive-part, which gas pipes usually are.
That statenent is correct as far as it goes, although I don't know how it affects the gas installation.
Perhaps the wording on your form should just ask if the bonding is present rather than satisfactory.
However, more recently some supplies have an insulating section which electrically separates the incoming pipe from the meter and consumer's pipework. In such circumstances it is the incoming pipe that should be bonded otherwise you may as well not bother. The electrical regulations have just corrected the misinformation it has been stating for years - I don't know why they have been wrong for so long.
With an insulating section and bonding on the consumer's side, nothing is achieved. It still might not be safe for you to touch both the incoming pipe and meter even with the meter still connected.
Either way (correctly bonded or not), you should, and I presume you do, when disconnecting a meter, temporarily bond the incoming pipe to the consumer's pipe.
All this, of course, presumes the supply pipe IS an extraneous-conductive-part, which gas pipes usually are.
OK - but, per what I keep saying, I'm not convinced that the person/persons who wrote those gas regulations understood anything much about electricity. As I've been implying, the statement ...
... makes little sense to me, since it seems to me that the opposite is the case. As I have said, the effect of bonding a gas pipe is that, under certain electrical fault conditions, extremely high currents could flow in the gas pipe, potentially leading to considerable local heating or even sparks in ther gas pipe, particularly in the vicinity of joints/unions. I would therefore have said that bonding a gas pipe does quite the opposite of "ensuring the gas installation remains safe under electrical fault conditions"!
As has been said, the gas pipework will almost always be connected to earth via the CPCs ('earth wires') feeding boilers, CH pumps and motorised valves etc., so the risk to which I refer already exists to some extent. However, adding bonding will, as far as I can see, make the situation appreciably less safe (gas-wise) by increasing the fault current.
If, as is commonly the case, the gas supply pipe does qualify as an extraneous-c-p then, electrically speaking, bonding is essential (to reduce the risk of electric shock), even if the result is to make the gas installation less safe.
Kind Regards, John
I suppose it depends whether they mean safe electrically or gasly
.Is there any danger gasly in an electrical fault situation? The gas won't burn/explode inside the pipe without a lot of oxygen.
You do have bare electrical contacts submerged in the petrol in the car.
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I have to say that I read it (and still do) to mean "gasly". The only sense I can think of in which the gas installation could become 'electrically unsafe' by virtue of the absence of bonding is by leaving an unbonded extraneous-c-p in the property - but that is surely of no concern to a 'gas safety inspection', is it? Would you expect someone doing an inspection of a 'water installation' to comment about the absence of electrical bonding?I suppose it depends whether they mean safe electrically or gasly
I suppose I should have been a bit more cautious, and written something like "if the presence/absence of bonding has any effect on the safety of a gas installation ('gasly'), I would have thought that it's presence would tend to slightly decrease safety of the gas installation ('gasly') ". Whilst the risk is clearly very small, I don't think it is zero - for example, a slightly imperfect gas union can result in both small gas leaks and sparks (if fault currents are flowing) - and, perhaps more to the point, local heating of unions due to very high fault currents might actually result in such imperfections of unions arising.
My main point was that I could not think of any way in which bonding could "ensure the safety of the gas installation" (gasly) - with the only effects I could think of beiong a (very small) risk of it doing the opposite.
As I understand it, long before plastic utility pipes started appearing (when the use of any utility pipe as a TT earth had to be prohibited), the use of gas pipes as TT earths was prohibited - was that not the case? In terms of gut feelings (even if misplaced) having the potential for very high electric currents to be flowing along gas pipework (with all the joints and other things involved) just doesn't 'feel nice' (or 'right') to me - does it to you?
Kind Regards, John
No. That's true but as you say the gas would presumably be 'safer' gasly without bonding so why instruct the inspector to verify it is there?
However, if we think that the inspector might be unnecessarily asked to verify it, then he would be in the same position as a water installer.
Not sure about then but it is prohibited now.
Whether that is justified, I don't know.
Why is the gas pipe not allowed to be used as a bonding conductor when that would only have the same effect?
Instinctively, no, but I don't know if that is correct - the same with the petrol but that is obviously alright.
Well, that was essentially my question. I see three possible answers ... Firstly, maybe, as you suggested, the 'safe' is meant to mean 'electrically', rather than 'gasly' - but, as I've said, I don't see that as a concern of a gas inspector (or what he is instructed to inspect). Secondly, maybe we are missing something. Thirdly, as I've already suggested, maybe those who instruct the inspector don't know much (enough) about things electrical! I may be doing those concerned a great injustice, but I have to say that I have some inclination towards the third of those possibilities!
I'm not sure that it would be "obviously alright" in a comparable situation - e.g. if petrol were flowing alone a metal pipe which had compression (or similar) joints (at its ends and maybe along its length), I'm not at all sure that it would be regarded as acceptable, let alone "obviously alright" to have a situation in which very high electric currents could, in some situations, flow along those pipes.
Kind Regards, John
But there is no absolute requirement for it to be there. There really isn't.
If you are taking money for a service which includes commenting on whether something is present or not then you must know if that something should be present. You really must.
Would you expect a customer to pay you to check if the pipework was painted to match the wall?
One may think
For it to be a check on a GAS safety check list, it must be their opinion it is required for GAS safety.
For it to be a check on a GAS safety check list, it must be their opinion it is required for GAS safety.
It must. However, as EFLI has said, when they say that bonding is necessary "to ensure the gas installation remains safe under electrical fault conditions" they might conceivably be talking about 'safe' in an electrical (rather than gas) sense - but that would seem odd, and unlikely, to me.
Beyond that, if we are talking about the gas installation 'remaining safe' gas-wise, unless we are all missing something, if bonding makes any difference at all to 'gas-wise' safety it would seem that it would theoretically make the gas installation slightly less safe.
So, either we're missing something, or the appearance of the item of the gas safety check list is the result of someone who does not understand the electrical considerations.
Kind Regards, John
Never assume those in charge know what they are doing.
On the form it asks "Is the main protective equipotential bonding satisfactory?".
Whilst we know what that means, perhaps they are actually referring to the wonderful cross-bonding below the boiler that plumbers are so fond of.
If not, then it is strange that they do not ask about the cross-bonding when they think it so important.
Whilst we know what that means, perhaps they are actually referring to the wonderful cross-bonding below the boiler that plumbers are so fond of.
If not, then it is strange that they do not ask about the cross-bonding when they think it so important.
@AndyPRK
Five pages of debating trying to argue electricians are right and gasmen are wrong, and ignorant of what is really required, so to jump fence and see it from electrical regs side.
Quote "
411 3 1 2 Protective equipotential bonding.
In each installation main protective bonding conductors shall connect to the main earthing terminal extraneous conductive parts including
1) Water installation pipes
2) Gas installation pipes
3) Other installation pipework and ducting.
4) Central heating and air conditioning systems
5) Exposes structural metalwork.
"
It qualifies the above by adding -
Quote "
Metalic pipes entering the building having an insulation piece at their point of entry need not be connected to the equipotential bonding.
"
That second quote clearly refers to that portion of metal pipe alone. It does not go on to say that the actual metal pipework listed above as part of the regulation also doesn't need earthing.
Five pages of debating trying to argue electricians are right and gasmen are wrong, and ignorant of what is really required, so to jump fence and see it from electrical regs side.
Quote "
411 3 1 2 Protective equipotential bonding.
In each installation main protective bonding conductors shall connect to the main earthing terminal extraneous conductive parts including
1) Water installation pipes
2) Gas installation pipes
3) Other installation pipework and ducting.
4) Central heating and air conditioning systems
5) Exposes structural metalwork.
"
It qualifies the above by adding -
Quote "
Metalic pipes entering the building having an insulation piece at their point of entry need not be connected to the equipotential bonding.
"
That second quote clearly refers to that portion of metal pipe alone. It does not go on to say that the actual metal pipework listed above as part of the regulation also doesn't need earthing.
I spent all my gas time carrying out appliance repairs and I would change that statement to 'Never assume anything'.
It doesn't matter what your gas people say, write or demand - It does not change how electricity works or the laws of physics.
So - if they are not e-c-ps they do not require bonding.
There you go then.
Yes it does, because then it would not be an e-c-p.
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