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Sorry my bad, this was at work,
I assumed people would get that by saying "New bloke"
At the time I was talking him through some of the machines we build, so in this situation it was....
Had I been in the chippy......
 
There is a section on ceiling grids in guidance notes 8 and it says
“The conductive parts of a suspended ceiling will not introduce a potential that does not already exist in the space in which the ceiling is installed. In normal circumstances, there is therefore no need to arrange for the conductive parts of the ceiling to be equipotentially bonded, which would be unnecessary as well as difficult and costly to achieve.” It later goes on to say that as long as all electrical equipment and cabling complies to BS7671 there is no need to bond.
 
Well, after laughing at this question initially, I was looking through a tendering document today and lo and behold one of the requirements was to bond all pipework, structural steel and suspended ceiling grids.

This was a council job, so you'd think there was someone who knows what's what.
 
Realistically a pain in the arse to confirm if extraneous if existing and if you have lots of fittings in it which are themselves earthed as they are exposed conductive parts so grid is likely already at earth potential from this.

If it's new you can test it with a IR tester at 500v. If >22kohms between bare grid and MET the you can consider it not extraneous.

If unproved, I'd shy away from bonding it as you then really should be adding supplementary bonding between sections to ensure the bonded potential across the whole grid, otherwise you are relying on bent steel joins maintaining your continuity which you are officially stating is bonded.

As it is very unlikely to be truly extraneous and unless you test and prove it, a better solution is to utilise a cpc from the largest circuit that supplies fittings in the grid and link that cpc onto the grid via a fly lead equal to cpc size and a ring crimp. This will ensure grid is at earth potential and will ADS under fault. The advantage of this is you are not vouching for the earth potential of the whole grid as it is not a requirement, whereas with bonding you will be albeit for a different reason.

To summarise, Bonding and cpc will both get grid at earth potential but if it is not truely extraneous then it should only be put at that potential by a cpc.......In my opinion of course!!
 
Well, after laughing at this question initially, I was looking through a tendering document today and lo and behold one of the requirements was to bond all pipework, structural steel and suspended ceiling grids.

This was a council job, so you'd think there was someone who knows what's what.

a contradiction in terms there, buddy.
 
Be a nice little earner; on an hourly rate, making up little earth links and self tapping screws across every joint in a suspended ceiling grid.
Can we make this a new regulation?

...and would you test to confirm each and every one?
....or just hope the testing at each and every point,picked up a problem...:)
 
I still can't believe anyone is going to provide every piece of a suspended ceiling grid with adequate earth bonding.
 
It still is in a lot of spec's we have and most of them seem to be generic except for a few pages. Is there anyone on here that used to have to do it? I remember when I was an apprentice or just after around the 15th (brown book) bonding all the pipes under a combi boiler (that all connected onto a metal bar) makes you wonder what the people writing the regs was thinking.
 
Talking to a new bloke today that said

"This might be a stupid question "

I said straightaway " No such thing as a stupid question "

He immediately says
" Do you like sausages?"
.......................
"Ok I'm wrong there is such a thing as a stupid question!"
Do you?
 
the tails look OK.the rest is beyond a monkey's abortion. don't use this for your niceic assessment.
It still is in a lot of spec's we have and most of them seem to be generic except for a few pages. Is there anyone on here that used to have to do it? I remember when I was an apprentice or just after around the 15th (brown book) bonding all the pipes under a combi boiler (that all connected onto a metal bar) makes you wonder what the people writing the regs was thinking.

I've done that many times Anthony, continuous 10mm all the way across with insulation stripped at each earthing strap and all with the same 'loop' between.
 

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