What do you think will be new/changed in the 18th edition?

[JohnW2]

You really need an astrologer or time machine - but, FWIW, I frankly doubt that any of the things you mention will be there.

How about deprecation of ring finals?

I very much doubt that one will be there, either. In a few decades' time, possibly, but not, I would have thought, any time soon.

Kind Regards, John

 

[securespark]

Yeah!

I know John you are a great supporter of ring final but I believe they are due for retirement, along with ye olde 3036.

The new standard in the up-coming Amd for non combustible consumer units is a good idea as I have seen countless dozens of burnt-out boards and main switches over the decades.

One good solution I have seen is to do away with the cage clamp terminals on the main switch that splay the strands when tightened and replace them with round terminals that have two securing screws for extra grip on the conductor.

This addresses one of the major causes of overheating within a consumer unit but does not make the enclosure non combustible. The obvious choice is metal, but there must be other materials.

 

[ekmdgrf]

This addresses one of the major causes of overheating within a consumer unit but does not make the enclosure non combustible. The obvious choice is metal, but there must be other materials.

Ceramic?
Asbestos?
Concrete?

 

[securespark]

Kevin from Grand Designs would like those.

Maybe not the Asbestos one.....

 

[JohnW2]

I know John you are a great supporter of ring final but I believe they are due for retirement...

I'm not sure what gives you that idea. I think we're probably nearly all agreed that, just like alcohol, tobacco, caffeine, aspirin and lots of other things, if they had made their first appearance in recent times, they undoubtedly would have been 'banned'! Having said that, ring finals have been with us for 60+ years, and I suspect that one would seriously struggle to find all that many cases where major issues (or catastrophes) had arisen because they were ring finals.

They probably will eventually be 'retired' from the regs (although I don't think for a long time yet), but that is going to cause a lot confusion for a long time, since a lot of such circuits will undoubtedly continue to be out there for several decades after they cease to be 'compliant'

One good solution I have seen is to do away with the cage clamp terminals on the main switch that splay the strands when tightened...

Isn't that meant to be an advantage? - tightening a screw, clamp or whatever onto something with a non-deformable circular cross-section results in only a pretty small contact area.

Kind Regards, John.

 

[RF Lighting]

I was told at college in 1998 that the 17th edition would abolish the ring final circuit, and BS1363 sockets would be replaced with BS4343 sockets as they were called back then....

 

[JohnW2]

I was told at college in 1998 that the 17th edition would abolish the ring final circuit, and BS1363 sockets would be replaced with BS4343 sockets as they were called back then....

Colleges often lie

I recently expressed my view that the 'abolition' (becoming non-compliant) of ring finals, if/when it happens, would probably result in confusion for several decades. However, that probably fades into insignificance in comparison with the confusion and chaos (again for decades) which would probably arise if we were ever to revert to to non-fused plugs (let alone giant unshuttered ones )! Were they also talking about "one socket per circuit"?

Kind Regards, John

 

[eveares]

I can't see Ring Final Circuits going away any time soon, yes they have their potential issues and dangers but they are very cost effective.

Asbestos?

I assume that this is a inside joke and not for real.


Will we see the voltage tolerance go from 230v +10%/-6% to 230v +10%/-10%

 

[JohnW2]

I can't see Ring Final Circuits going away any time soon, yes they have their potential issues and dangers but they are very cost effective.

I think you might struggle to argue that they are "very cost effective". For a start, if one cut a 32A ring final in the middle to create two 20A or 25A radials, the only difference in cost would be two or three quid for one additional MCB. In fact, if you measured "cost-effectiveness" in terms of 'cost per amp' it would presumably be appreciably greater for the 40A or 50A worth of radials than for the 32A ring final.

Will we see the voltage tolerance go from 230v +10%/-6% to 230v +10%/-10%

I don't think that BS7671 has any control over that.

Kind Regards, John

 

[ban-all-sheds]

I don't think that BS7671 has any control over that.

Some people think they do have control over it even though they don't.

 

[SimonH2]

I think you might struggle to argue that they are "very cost effective". For a start, if one cut a 32A ring final in the middle to create two 20A or 25A radials, the only difference in cost would be two or three quid for one additional MCB.

OK, your argument has merit - except for one detail.
At the moment, many manufacturers,ranges don't have 25A - particularly for RCBOs. So that means 20A. Now put a kitchen on a 20A MCB and wait for the phone calls when a customer has the washing machine and tumble dryer going - then puts the kettle on for a cuppa. Oh, hang on, didn't someone say the EU might be banning 3kW kettles - perhaps that's why

But overall, yes I agree - 20 or 25A* radials make a lot of sense. I have to admit I've been wondering if I can get away with "downgrading" the house to 2x20A radials as it'll make life a lot easier for that prolonged period between "starting to rearrange the ring" which is not far off and "everything finished" which could be quite a few years away. The way the current ring is done makes splitting it (eg up and down) quite difficult without making a mess - which ideally means doing each bit as we redecorate a room.

* As an aside, anyone got a suggestion for a board which has 25A RCBOs but is reasonably economical. The last ones I used were ProElec (the brand CPC sell at £12 ea for an RCBO) - though they are a PITA as the RCBOs are an old design and very long which means a cramped board.

 

[JohnW2]

I think you might struggle to argue that they are "very cost effective". For a start, if one cut a 32A ring final in the middle to create two 20A or 25A radials, the only difference in cost would be two or three quid for one additional MCB.

OK, your argument has merit - except for one detail. At the moment, many manufacturers,ranges don't have 25A - particularly for RCBOs. So that means 20A.

Indeed.

Now put a kitchen on a 20A MCB and wait for the phone calls when a customer has the washing machine and tumble dryer going - then puts the kettle on for a cuppa. Oh, hang on, didn't someone say the EU might be banning 3kW kettles - perhaps that's why

Quite so - and that is the very reason why I personally don't favour 20A (or even 25A) multi-socket circuits of any design, except in obviously 'low demand' areas - even a 25A circuit is theoretically not quite enough for 2x13A loads. Hence, in practice, the choice I would personally usually be making (particularly for a kitchen) would therefore between a 32A ring final and a 32A (4mm²) radial. I obviously used the 20A/25A 2.5mm² radials in what I wrote, because of the nature of the comparison I was making with a ring final ('chop it in half').

But overall, yes I agree - 20 or 25A* radials make a lot of sense.

As above, I would personally favour 32A radials, except in 'obviously low load areas'. A circuit with maybe a dozen 13A outlets that can only handle 20A or 25A does not, in general, seem or feel ideal to me, even if it is theoretically 'safe'.

Kind Regards, John

 

[skotl]

Massively off topic, but happy 20,000th post, John

 

[JohnW2]

Massively off topic, but happy 20,000th post, John

Goodness - I didn't realise I was even approaching that! Thanks

Kind Regards, John

 

[SimonH2]

Hence, in practice, the choice I would personally usually be making (particularly for a kitchen) would therefore between a 32A ring final and a 32A (4mm²) radial.

But for many installations, I think you'll find that a 32A radial using 4mm cable uses more copper than a 32A RFC using 2.5mm cable. It does depend on the topology, but in most houses, to "close the ring" doesn't actually need all that much extra cable. Since 4mm cable has 60% more copper than 2.5mm, that means you can add nearly 2/3 of the radial length to complete the ring before you are using more copper in the (2.5mm) RFC than in the (4mm) radial. In most houses, it would be difficult to exceed that with a sensible cable route.

Not to mention, it's hard enough terminating multiple 2.5mm cables in some of the socket/backbox combinations - 4mm can't be easier

Massively off topic, but happy 20,000th post, John

Wow, I've some catching up to do