Doubling over copper conductors

[Harry Bloomfield]

one thing to mention: pro electricians hate it when wires are twisted together

Correct! It used to be good practice to twist up the likes of 7/029 to make a neat single bundle for best contact, but that is no longer the case with modern metric single strand cables. Twisting singles reduces the contact area with the terminal and makes testing/modification more difficult/more likelihood of conductor breakage.

 

[winston1]

On a ring circuit, where you have two 2.5mm cables, do you double over the cables into each terminal? Whilst I understand the principle, I wanted to understand its application in this situation please.

I don’t. It’s a pain if you want to add a spur later.

 

[EFLImpudence]

On a ring circuit, where you have two 2.5mm cables, do you double over the cables into each terminal?

Why do you specify a ring circuit?

Is there a difference between a ring circuit and a radial in this matter?

 

[Jupiter01]

Why do you specify a ring circuit?

Is there a difference between a ring circuit and a radial in this matter?

The radial has a single set of wires for the last socket whereas the ring will have at least two sets for every socket.

 

[EFLImpudence]

So - apart from the last socket, what is the difference as far as your question is concerned?

 

[JohnW2]

It is good practice to double over the wire for ring circuits where we have two conductors going into each terminal or is this only necessary when you have a single wire per terminal?

As bernard has implied, I think this is yet another situation in which common sense should prevail.

Kind Regards, John

 

[sparkwright]

As regards to connecting two cables to a socket:
1) I wouldn't double over the lives and neutrals.
2) I may consider doubling over the (much smaller) earth wires, particularly with modern square terminals, to ensure good contact.

 

[JohnW2]

As regards to connecting two cables to a socket: .... 1) I wouldn't double over the lives and neutrals.

Not even if, thanks to Amd2, you were contemplating a 16A 1.0mm² radial (or, say, the terminals of a 20A switch on a 16A 1.0mm² immersion circuit)? ... particularly given ...

.... 2) I may consider doubling over the (much smaller) earth wires, particularly with modern square terminals, to ensure good contact.

With 1.0mm² T+E, the L & N would, of course, be the same size as the CPC, not "much larger"

Kind Regards, John

 

[sparkwright]

My post was referring to using 2.5mm2 cable, with 1.5mm2 earth.

I am assuming regular twin and earth cable for all situations.

IF, IF, IF I was using two 1.0mm2 cables, I would therefore double the ends over on all of the wires.

IF I was using two 1.5mm2 cables, I would double the ends over on all wires.

IF I was using one 2.5mm2 cable and one 1.5mm2, cable, I would not double over the 2.5mm2 live and neutral, but I would double over it's 1.5mm2 earth. On the 1.5mm2 cable, I would double over the live and neutral, and I would double over the 1.0mm2 earth.

 

[JohnW2]

My post was referring to using 2.5mm2 cable, with 1.5mm2 earth.

I guessed it probably did, although you didn't actually say so.

IF, IF, IF I was using two 1.0mm2 cables, I would therefore double the ends over on all of the wires. IF I was using two 1.5mm2 cables, I would double the ends over on all wires. IF I was using one 2.5mm2 cable and one 1.5mm2, cable, I would not double over the 2.5mm2 live and neutral, but I would double over it's 1.5mm2 earth. On the 1.5mm2 cable, I would double over the live and neutral, and I would double over the 1.0mm2 earth.

Probably same here. In other words you would, in general, double over any conductor of 1.5mm² or less, but not if were bigger. Thinking of my own practices, it would also depend upon the number of conductors - if there were three or more 1.5mm² (or smaller) ones, I might not double them over.

Kind Regards, John

 

[Jupiter01]

So - apart from the last socket, what is the difference as far as your question is concerned?

No difference. Thought I'd state a ring. Else people may think I am referring to a single cable per terminal

 

[EFLImpudence]

People often say a socket has two cables therefore it must be a ring but (apart from the last socket) a radial looks exactly the same.

 

[FrodoOne]

one thing to mention: pro electricians hate it when wires are twisted together

Really !

Twisting several (or "many") 2.5 mm² CSA stranded conductors is quite normal in Australia/NZ
(See https://commons.wikimedia.org/wiki/File:Dual_3_Pin_Socket_Outlet_Wiring.jpg )

Of course, it is the "norm" here that all conductors over 1 mm² CSA actually "used" are "stranded" - since the cables containing them are much easier to work with than any with solid conductors.

 

[Taylortwocities]

Really !

Twisting several (or "many") 2.5 mm² CSA stranded conductors is quite normal in Australia/NZ
(See https://commons.wikimedia.org/wiki/File:Dual_3_Pin_Socket_Outlet_Wiring.jpg )

Of course, it is the "norm" here that all conductors over 1 mm² CSA actually "used" are "stranded" - since the cables containing them are much easier to work with than any with solid conductors.

Which proves how far you lot have drifted from civilisation!

 

[JohnW2]

Twisting several (or "many") 2.5 mm² CSA stranded conductors is quite normal in Australia/NZ

I would imagine that most/all of the 'older' people in the UK would say/admit that such was what they once did (and probably were taught to do) - and many continued the practice for a good while (some maybe even to today ) when solid conductors became common.

With stranded conductors, it probably does no harm, and may well still be a good idea (and I would certainly do it with 'very small conductors), but the risk with solid ones is that the act of twisting them together can weaken, or even fracture, some of them (and potentially also have an effect on the 'local CSA').

Kind Regards, John