Outdoor sockets

[JohnW2]

Installing a ring final circuit in 2022 achieves absolutely nothing.

... other than CPC redundancy (and often less VD), although I accept that there are good few 'cons' to balance that 'pro'.

If you're considering the alternative to be a 4mm² 32A radial, then I'm inclined to agree with you but, as I've often said, I'm personally not all that comfortable with the concept of a 20A multi-socket sockets circuit.

I've always thought that it's a bit of a pity that we don't have 3.0mm² T+E available!

Kind Regards, John

 

[scousespark]

Radials and there are few installations where a 20 or 16 amp radical is not sufficient.

 

[sparkwright]

Installing a ring final circuit in 2022 achieves absolutely nothing.

'Course it does.

It gives you a 32amp circuit without having to bother with using 4.0mm2 cable.

A very efficient way of getting the most out of 2.5mm2 cable.

 

[JohnW2]

Radials and there are few installations where a 20 or 16 amp radical is not sufficient.

I agree (although one might have to think about what one regards as 'sufficient' in the context of a kitchen or utility room, particularly if one is contemplating a 16A circuit), but the problem with sockets circuits for designers is that they don't have crystal balls, so I remain a little uncomfortable with the concept of a circuit with many sockets which could theoretically be 'overloaded' by what was plugged into just one double socket.

Whilst the pragmatist within me has great sympathy for what you say, I'm sure that I don't need to tell you the danger of an approach based on there being "...few installations where <whatever>". I can think of many situations where I would be tempted to take that approach, but it would often have the regs and many others (maybe including yourself) 'having kittens'

Kind Regards, John

 

[JohnW2]

'Course it does. It gives you a 32amp circuit without having to bother with using 4.0mm2 cable.

Maybe it's just me, but I personally find 4mm² T+E nicer to work with than 2.5mm², so I certainly would not regard it as 'bother'.

A very efficient way of getting the most out of 2.5mm2 cable.

If it's 'efficiency' that interests you, you could probably have a 50A radial, using no more cable than a ring, by having 2 x 2.5mm² cables (Method C) in parallel

Kind Regards, John

 

[cdbe]

This is where it's going:

I think I'll go for this:

It's on offer at £30, gets good reviews and the WiFi on our patio (where it's going) is crap. The sockets will just be used for fair weather laptop/phone charging etc.

 

[flameport]

That is a type AC RCD, which is no longer suitable for socket outlets.

 

[sparkwright]

Maybe it's just me, but I personally find 4mm² T+E nicer to work with than 2.5mm², so I certainly would not regard it as 'bother'.

If it's 'efficiency' that interests you, you could probably have a 50A radial, using no more cable than a ring, by having 2 x 2.5mm² cables (Method C) in parallel

Kind Regards, John

It's a struggle trying to get two 4.0mm2 wires in the feed side of a Crabtree 20amp double pole switch module, especially when you have 252 to do.

Don't like the 50amp radial idea much, as branching would mean a socket could have six 2.5mm2 cables in it, which would be irksome.

 

[JohnW2]

It's a struggle trying to get two 4.0mm2 wires in the feed side of a Crabtree 20amp double pole switch module, especially when you have 252 to do.

I'm sure it would be - but, fortunately, few domestic installations would have 252, if any, such issues!

Don't like the 50amp radial idea much, as branching would mean a socket could have six 2.5mm2 cables in it, which would be irksome.

I don't like the idea, either, and would certainly never consider doing it - and, as I hope you realised, I was not offering it as a serious suggestion. However, you were claiming that a 32A ring final was a "very efficient way of getting the most out of 2.5mm² cable", despite that total CSA of 5mm² is more than would even be needed (Method C) for a 32A radial - which is why I illustrated a 'more efficient' theoretical way of "getting the most out of 2.5mm² cable"

Kind Regards, John.

 

[JohnW2]

That is a type AC RCD, which is no longer suitable for socket outlets.

Are you suggesting that if one adds a socket to an existing sockets circuit which is protected by a Type AC RCD (which I presume must currently be the case with the great majority of UK domestic sockets circuits) one must change the RCD to Type A or 'better'?

Kind Regards, John

 

[cdbe]

That is a type AC RCD, which is no longer suitable for socket outlets.

Ok. What can I do, RCBO?

 

[flameport]

What can I do

Change the RCD to a Type A, or put that circuit on a Type A RCBO if the consumer unit is suitable for one.

 

[flameport]

Are you suggesting that if one adds a socket to an existing sockets circuit which is protected by a Type AC RCD (which I presume must currently be the case with the great majority of UK domestic sockets circuits) one must change the RCD to Type A or 'better'?

Any additions or alterations comply with the latest edition or amendment, which in this case requires a Type A RCD or better.
BS7671 Part 1, Fundamental principles.

 

[cdbe]

Change the RCD to a Type A, or put that circuit on a Type A RCBO if the consumer unit is suitable for one.

Thanks. As the whole house is being redone/extended in bits and pieces I'll probably replace both RCDs - so it's the ones with 2 squiggles on the front.

 

[JohnW2]

Any additions or alterations comply with the latest edition or amendment, which in this case requires a Type A RCD or better. BS7671 Part 1, Fundamental principles.

Thanks for answering my question, even though, as you presumably understood, it was essentially rhetorical, since I already knew the official (per BS7671) answer.

In terms of BS7671, you are obviously right (following the recent appearance of Amd2) in what you say (for a sockets circuit). However, countless non-electricians extend sockets circuits. They will presumably continue to do so, and I cannot help but wonder (in common-sense, not regulatory, terms) how wise it is to advise them (the great majority of them) to 'fiddle around in their CU' (to change the RCD/RCBO) as part of the work.

It's difficult, since one does not want to suggest, let alone 'advise', people to do things which are non-compliant with BS7671. However, given that the intent of the regulation is presumably the opposite, it seems somewhat ironic that 'correct advice' may increase the risk of electric shock (hence injury and maybe even death) when people extend (or otherwise modify) sockets circuits.

Kind Regards, John