I'm not so sure about the "concept of earthing" - I suspect that you are talking about the BS7671 definition of 'earthing'. In a more general sense, "earthing" merely refers to connecting something to earth - and in some situations (e.g. RF circuitry, screening etc.) that hasn't necessarily got anything to do with exposed-c-ps, METs, protection or protective devices.
As above, that depends upon what definitions one is using.
That's an interesting one. Strictly, in terms of BS7671 definitions, BAS is probably right, but eric's standard lamp falling onto to some exposed metalwork creates exactly the same hazard as would be created by an internal fault resulting in the exposed-c-ps (if not earthed) of electrical equipment becoming live - so, if one thought like eric, it would not be unreasonable to think of his (electrically floating) pipes/radiators as being equivalent to an exposed-c-p.
I don't think anyone, even eric, has suggested that there is any such 'requirement
I think that you and I have the same view about that - but others (maybe including eric) may have different views.
As above, we certainly dont 'have to', and many/most of us wouldn't - but some might.
See above.
Fair enough - I look forward to hearing.
Indeed - so the same, in varying degree, as the sagas of metal baths, doorknobs and forks. Furthermore, not only is eric's 'standard lamp' scenario incredibly improbable, but so it is extremely unlikely that metal CH pipework and radiators would not already be earthed (well, 'connected to earth' - see below
) - that could only happen if there were a mixture of metal and copper piping in the CH system.
But I maintain that in the scenario we are discussing, the pipe is being treated as an exposed-c-p.
Nor is there any pd to equalise.
Thanks. As I said, it would be crazy to require bonding of metal gas/water pipes within a building (even if you called them 'parts of the {plumbing} installation') if they entered the building as plastic - so I can't believe that is what is intended.
In which case what makes any metal pipes they connect to inside the building extraneous-conductive-parts?
[should that latter one read "extraneous-c-p"?]
As I said, there does not have to be a potential to equalise at the point in time that one installs a bonding conductor - for example, there probably is often little, if any, pd present when one installs standard main bonding. It's a matter of what pds could (in the absence of the bonding) arise in the future under abnormal/fault conditions.
No, if only an exposed-c-p can be earthed then earthing it must make it an exposed-c-p.
Then it follows that it must NOT be earthed - problem solved.
But equalising pd is not the purpose of the connection therefore it cannot be bonding.
Well, it could be connected via a bit of G/Y cable to the earth of the installation, whether BS7671 called that 'earthing' or not. However, as I said, if it can't be 'BS7671 earthing', BS7671 might well regard it as 'bonding'!
As I've said many times, some designers might say that such was the reason they had installed the G/Y cable - to ensure that a dangerous pd could never exist between two simultaneously touchable metal parts.
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
