Chris Pearson said:

(I might add that there is nothing which prevents me from putting a notice there.)

Agreed, BS 7671 is a "minimum standard" and you can go over and above.There is nothing wrong with putting notices where you see fit.

However, I believe we were discussing whether the DNO's earthing terminal in a service head was an MET, and I still don't believe it is.

Chris Pearson said:

Clearly, in this instance (TN-S/PILC), there has to be a separate MET.

Really? Henley do an SNE service head (that has a CNE link too) where the link from the PILC or armour of TN-S can be brought into the service head earthing terminal.

The absolute best bit about that kit, is you have no clue from the outside whether you have TN-S or TN-C-S !

The absolute best bit about that kit, is you have no clue from the outside whether you have TN-S or TN-C-S !

Or for that matter the occasionally seen weedgrowers special edition config , where the provision for looped supply can be misused to export an unfused live via the CPC terminal....  the giveaway is the G/Y disappears behind the wooden board as fast as possible with no bare metal MET, and perhaps a neutral derived earth from somewhere else.
In some err, perhaps 'less trusting' countries than the UK, meter boxes, supply terminal covers and similar kit are made transparent so that the internal wiring, and any ingress of water or insects, can be seen and visually inspected by any interested party to be correct and in good condition. Such an approach has much to recommend it.
Mike

gkenyon said:

The current requirement (with current wording) I believe appeared in Amendment 1:1994 to BS 7671:1992, so has been in place for 30 years.

For general interest.

I will add to this, that it was only in 2022 that the requirement for the notice to conform to BS 951 (standard for bonding clamps, which had an embossed metal 'label') was removed. Of course, the "sticker", "screw on plastic" and engraved laminated versions of the notice strictly didn't conform to BS 7671 between 1991 and 2022 (although lots were fitted and no-one cared).

From BS 7671:2018+A2:2022, as per Regulation 514.9.2, all notices should conform to the standards for user instructions (and safety signs if appropriate, e.g. warning notice), and permission is given to use the bonding clamp version for this Regulation:

I was just pointing out how the interpretation of a word or phrase that is exact for some can often have a very different connotation for others. If we bolted the MET to the outside of the switchgear, it would no longer be separate from it. Strict reading of the indent would lead one to conclude that a safety notice would not be required. 

So the use of the word "separate" is not ideal if the regulation is trying to convey that a notice is not required if the MET is established within the main switchgear.

However, I am happy to lean towards Chris Pearson's view in terms of the mischief rule.

Interestingly, in the Irish Regs (IS1010-1) 2020 there is no requirement for a safety notice at the MET although, like BS7671 2018 A2 2022, 134.1.7 says "where necessary for safety purposes, suitable warning signs and/or notices shall be provided"

lyledunn said:

If we bolted the MET to the outside of the switchgear, it would no longer be separate from it.

I find it difficult to argue otherwise.

So is this one separate or not? (Strictly speaking, it is a building earth terminal rather than the MET.)

lyledunn said:

If we bolted the MET to the outside of the switchgear, it would no longer be separate from it.

Agreed, but you would be modifying the switchgear assembly, which is outside the scope of BS 7671. BS EN IEC 61439 series addresses marking requirements for the assembly.

lyledunn said:

So the use of the word "separate" is not ideal if the regulation is trying to convey that a notice is not required if the MET is established within the main switchgear.

I disagree based on the above.

lyledunn said:

However, I am happy to lean towards Chris Pearson's view in terms of the mischief rule.

I have no problem with that, BS 7671 is a "minimum" ...

lyledunn said:

Interestingly, in the Irish Regs (IS1010-1) 2020 there is no requirement for a safety notice at the MET although, like BS7671 2018 A2 2022, 134.1.7 says "where necessary for safety purposes, suitable warning signs and/or notices shall be provided"

Yes, BS 7671 (and preceding Wiring Regs) never used to have a requirement until 1994.

Chris Pearson said:

So is this one separate or not?

Clearly, yes, it's separate and not part of the assembly.