What does Earth Bonding involve?

[John D v2.0]

You know I'm not implying that you are deliberately misleading us

well, I didn't, but thanks for clarifying, and please avoid making statements of what I know or what I am trying to do, because you can always ask them as a question if you feel I am doing or thinking something.

 

[JohnW2]

My position is that when I mentioned it in my post, I was meaning according to the iet definition, and anyway my original point still stands that bonding is important.

... and I totally agree with that point.

It seems to have been forgotten that the exchanges over the past couple of pages started because I asked Andy why he had challenged your statement about the importance of bonding (and then confuse me even more by responding "bonding saves lives").

Kind Regards, John

 

[JohnW2]

Well I think we understand each other, your position is that if it's what they think it is it should be called EEBADS or ABCDEFG or something else random, and not misleadingly call it ADS. ... My position is that when I mentioned it in my post, I was meaning according to the iet definition ...

Fair enough, but I still struggle to understand what this 'definition' (there isn't actually a definition in Part 2 of BS7671) is trying to say. I presume you are referring to this ...

It surely can't be intended to mean ...

Automatic disconnection of supply consists of the following ...

• basic protection
• protective earthing
• protective equipotential bonding
• Automatic disconnection of supply

... can it?

It just doesn't make sense to say that <something> consists of three other things plus that <something> (particularly when those three other things appear to have absolutely nothing to do with the <something>), doses it? So, what on earth IS it trying to say?

That list seems to be a list of all of the main measures required by BS7671 to provide 'Protection Against Electric Shock' (i.e. all of Chapter 41 of BS7671), so to call it "ADS" (which is just one of the many measures) seems just plain daft to me. Should it not simply be called "Measures for Protection Against Electric Shock", or something like that?

Kind Regards, John

 

[John D v2.0]

Yeah it does seem daft and I'm not sure why they dropped the eeb part of the acronym, there's probably a lot of simplification there otherwise the acronym may be too long. If it was BIPEPEBADS everyone would be "wtf"when writing out the certificate. Maybe they just need a new name.

 

[JohnW2]

Yeah it does seem daft and I'm not sure why they dropped the eeb part of the acronym ...

I really don't think it was much less daft even before they did - I still don't think it makes sense to lump all sorts of essentially different things together, and probably even less sense to do so and then give them a name which encompasses just two of the several!

... Maybe they just need a new name.

As above, I'm far from convinced that it makes any sense to lump together, and give a name to, a whole pile of different things at all - but, as I said in my previous post, if one really wants to do it, it would make sense to name that 'heterogenous package' in terms of the one common feature (in terms of purpose), hence something like "Measures for Protection Against Electric Shock" (aka Chapter 41 of BS7671).

Kind Regards, John

 

[bernardgreen]

All this is about faults that occur down stream from the point where Automatic Disconnection of Supply occurs. This point is Consumer Unit with MCBs for current overload and RCD for leakage to Earth.

It does not adequately cover the protection of life and property when there is a fault up stream from the point where the Automatic Disconnection of Supply equipment is installed.

 

[Risteard]

ADS is identical to EEBAD.

Protective Equipotential Bonding absolutely is part of ADS.

The term ADS was adopted to harmonise the term.

 

[John D v2.0]

Quoting isn't working but @JohnW2 i think we're in agreement but i think you are a lot more incredulous about it than me. i think the only way to move forward in this one is to get in touch with iet and ask them to improve their terminology for next time.

 

[JohnW2]

ADS is identical to EEBAD. ... Protective Equipotential Bonding absolutely is part of ADS. ... The term ADS was adopted to harmonise the term.

... and you think that any of that makes sense?

Electrically speaking, in what sense is bonding "absolutely part of" Automatic Disconnection of Supply? Put another way, under what circunstances can the presence or absence of bonding affect whether or not ADS occurs satisfactorily when it should?

Kind Regards, John

 

[JohnW2]

Quoting isn't working but @JohnW2 i think we're in agreement but i think you are a lot more incredulous about it than me.

Yes, I think that we are generally in agreement.

But, also yes, I'm pretty incredulous. BS7671 is written by, and reviewed by, a large group of people, virtually all of whom have (or should have) a very good understanding of matters electrical, and certainly should understand about things like bonding, 'automatic disconnection of supply', basic insulation etc. - so it does seem a little 'incredible' that they should adopt a term to encompass a number of very different things which really is 'not correct' (and certainly not 'sensible') in any sense that I can think of.

i think the only way to move forward in this one is to get in touch with iet and ask them to improve their terminology for next time.

It's already on my list of things to raise when the DPC of the next amendment of BS7671 appears - but, since nothing I've written in response to previous DPCs has ever had any effect, I won't be holding my breath!

Kind Regards, John

 

[Risteard]

Quoting isn't working but @JohnW2 i think we're in agreement but i think you are a lot more incredulous about it than me. i think the only way to move forward in this one is to get in touch with iet and ask them to improve their terminology for next time.

It's not up to the IET. It comes from IEC documents.

 

[Risteard]

... and you think that any of that makes sense?

Electrically speaking, in what sense is bonding "absolutely part of" Automatic Disconnection of Supply? Put another way, under what circunstances can the presence or absence of bonding affect whether or not ADS occurs satisfactorily when it should?

Kind Regards, John

It's what ADS means. That's what the protective measure encompasses. I'm not sure why you're getting so hung up on the name.

I preferred the term EEBAD but it was one of the terms lost to harmonisation once the 16th Edition was withdrawn.

 

[EFLImpudence]

It's just another example of where something has been altered (for whatever reason) and the ramifications for the rest of the regulations have not been considered.

 

[JohnW2]

It's what ADS means.

It is perhaps being overlooked in this discussion that "ADS" does not appear anywhere in the current version of BS7671 (and maybe never has in previous editions). It does have a good few mentions of "Automatic disconnection of supply", but I would like to think that "Automatic disconnection of supply" means Automatic disconnection of supply.

That's what the protective measure encompasses.

Wrong way around. 'Protective measures" (against electric shock) encompasses 'Automatic disconnection of supply', not the converse. Hammers are tools, but it would be ridiculous to describe all tools as hammers.

I'm not sure why you're getting so hung up on the name.

I find it intellectually offensive that intelligent and knowledgeable people could have come up with such confusing (and logically incorrect) terminology - and still find it hard to believe that such was really their intent.

Kind Regards, John

 

[EFLImpudence]

It surely can't be intended to mean ...

Automatic disconnection of supply consists of the following ...

• basic protection
• protective earthing
• protective equipotential bonding
• Automatic disconnection of supply

... can it?

Simply put -

A = B + C + D + A

is not possible.