Two spurs from one socket

[rrodd]

Hello
I'd like to add an outside socket and outside light from a double socket ring main.
I know I could add a FCU to the outside socket as a spur, then add another FCU for the light, but is that the best way to do it?

I was wondering how many put tubing through the cavity wall for the cable, and how many just feed the cable through the wall into the socket /FCU?

 

[EFLImpudence]

I'd like to add an outside socket and outside light from a double socket ring main.
I know I could add a FCU to the outside socket as a spur, then add another FCU for the light, but is that the best way to do it?

No.

As your thread title (I think unintentionally) states - have a separate spur for socket and light, then you don't need any FCUs.

I was wondering how many put tubing through the cavity wall for the cable, and how many just feed the cable through the wall into the socket /FCU?

Who knows? Was it on the census?

It is no great hardship to insert a tube.

 

[Taylortwocities]

Although it is permissable to connect two separate spurs to one socket on a ring final, the practicalities of being able to reliably connect FOUR conductors each of 2.5mm² csa to the terminals on the back of a socket makes it difficult.

 

[EFLImpudence]

Stop buying sockets which are not fit for purpose.

Not sure what is meant by 'reliably'.

Are we back in teeny weeny socket land? We did all this recently.


MK Logic:

If it takes 2 x 6mm² (and/or 3 x 4mm²) then it will take 4 x 2.5mm².




I don't have any UK sockets here. Would someone please measure the actual size of a typical socket terminal and let me know or post a link?

 

[EFLImpudence]

Ah, found one.

Click Scolmore - the same for their metal clad sockets:

https://www.scolmore.com/_pdfs/spec_bros/Metal%20Clad%20Sockets.pdf

where it states 5mm. diameter.

Click Mode Switched Double Socket 13A DP | CMA036 | Powersaver Electrical & Security Distributors

Click Mode Switched Double Socket Click Mode 13A 2 Switched Double Socket Outlet is suitable for a maximum voltage of 250V with a load rating of 13A. What's more, each switch features a sleek rounded profile and a white plate finish ideal for contemporary interiors. Plate Design & Finish Rounded...

www.powersaver.co.uk

Strangely enough they state 4 x 2.5mm² but 2 x 4mm² (sort of) so clearly such information is not reliable.

In actual fact 5 x 2.5mm² would easily fit in a 5mm diameter terminal.

 

[Taylortwocities]

By “reliably” I am thinking about the few times that I have had to deal with this situation, where at least one of the four conductors isn’t properly secured by the terminal screw. So I was not dissing your input, just trying to pass on my advice as it may not be as easy at it first appears.
And in your perfect practical World it may be mathematically possible to put 4x2.5 into a 5mm hole, but just suppose the back box is only 25mm. Been there, tried that. Not so easy.

 

[JohnW2]

.... I have had to deal with this situation, where at least one of the four conductors isn’t properly secured by the terminal screw.

Doesn't that theoretically become an increasing risk as the number of conductors decreases ?

Kind Regards, John

 

[sparkwright]

Doesn't that theoretically become an increasing risk as the number of conductors decreases ?

Kind Regards, John

You would think so, but not always the case - usually with square terminals.

For some reason, if you try to fit 3 or 4 solid 2.5mm2 conductors in a modern MCB, you will often have a loose wire.

Annoyingly.

 

[sparkwright]

Personally, rather than trying to spur off a socket twice, I would rather do a little joint at the socket and extend the ring, so everything has two cables and all directly on the ring.

It makes it so much easier for future additions, and bearing in mind it could be me doing them, I prefer this way.

 

[EFLImpudence]

You could always used an unfused spur; there is plenty of room for several conductors.

 

[JohnW2]

You would think so, but not always the case - usually with square terminals.

Fair enough - I suppose it can work both ways. Particularly with large terminals,if there are just one or two conductors, one or both may 'slip down the side of the screw'.

For some reason, if you try to fit 3 or 4 solid 2.5mm2 conductors in a modern MCB, you will often have a loose wire.

That's a bit different, isn't it, because one is then not talking of a situation in which a screw is tightening directly onto conductors? However, at least in my (limited) experience, having three or more conductors which are not all of the same size in such a terminal can be a big problem, with the smallest one potentially remain loose.

Kind Regards, John

 

[JohnW2]

Personally, rather than trying to spur off a socket twice, I would rather do a little joint at the socket and extend the ring, so everything has two cables and all directly on the ring. It makes it so much easier for future additions, and bearing in mind it could be me doing them, I prefer this way.

There's clearly a fair bit to be said for that approach, the 'price' being 'additional joints' (even if 'little' ones ).

Kind Regards, John

 

[EFLImpudence]

For some reason, if you try to fit 3 or 4 solid 2.5mm2 conductors in a modern MCB, you will often have a loose wire.

Annoyingly.

You could always do it properly and ensure that does not happen.

 

[sparkwright]

Fair enough - I suppose it can work both ways. Particularly with large terminals,if there are just one or two conductors, one or both may 'slip down the side of the screw'.

That's a bit different, isn't it, because one is then not talking of a situation in which a screw is tightening directly onto conductors? However, at least in my (limited) experience, having three or more conductors which are not all of the same size in such a terminal can be a big problem, with the smallest one potentially remain loose.

Kind Regards, John

Yes, you are correct about the terminal on a modern MCB not having a screw connecting directly to the conductors - but either way, it seems the more conductors you have, the greater the chance of one conductor slipping the net.

And I blame this on poorly designed terminals.

Just lately I have noticed large terminal holes with a screw that is too skinny. So there is too much space between the inside of the 'tunnel' and the screw.

Where some conductors are smaller than the others, I tend to double over the end of the thinner ones - but even this is not fool proof.

 

[EFLImpudence]

I don't understand your attitude. It seems to be that you do something in a particular way and sometimes the result - because of the design of certain accessories - is unsatisfactory.