WIRING ADVISE

[BARCUD]

Hopefully help at last ! I'm modernising our house and one job I am involved with at the moment is moving wall switches and sockets around. This is going to be a question you have heard a million times I guess so 'sorry' in advance.

I am moving a double wall light switch which has 6 cables in 2 sheaths. Part of a ring main? 3 for each switch I guess. The new position is longer than the existing cable will allow so I need to extend the existing cables. Can I just join each cable with 30amp blocks? or can I use two 3 way junction boxes to make the joins? am I on the right track?

thanks guys, BARCUD

 

[davelx]

No, not part of a ring main - or even a ring final

Are the lights that these switches control also switched from another set of switches somewhere else (this sounds like a simple case of two, 2-way switches)?

If you extend the cables using junction boxes or terminal blocks (10A would do for a lighting circuit), then they must remain accessible for inspection and test - you cannot plaster/board/build over them, you woul dhave to fit a blanking plate and leave it visible.

I suspect that you do not want to do that, so you will need to use crimped or soldered joints - there are loads of posts here on how to do that.

If you can post a photo of the connections on the back of the switchplate (all wires in place) and showing which cores go into which sheaths, we can advise further

 

[BARCUD]

Many thanks for the swift reply.

Yes, this double switch controls 2 lights which are also controlled by 2 single switches also.

Good, I have both junction boxes and terminal blocks I could use. At the moment I have the ceiling off which means I have access to the floor joists so the terminal boxes can be screwed to these and they could then be accessed for later inspection from under the upper floorboards. Not sure what a 'blanking plate' is though !?

Photo's wouldn't be possible at the moment.

To recap - I can make the wire connections with either 2 junction boxes OR connect each corrosponding wire individually with terminal blocks, these can be 15amp.

QUESTIONS ? - a blanking plate ?
- when joining wires in a similar way for a plug socket do
I need to use 30amp blocks ?can I use 30amp forboth?

many thanks again, BARCUD

 

[Space cat]

could then be accessed for later inspection from under the upper floorboards

Opinions on this site vary as to whether that would count as accessible. If you are going to do this, the least you should do is have a piece of board which can be easily unscrewed and lifted for access.

Not sure what a 'blanking plate' is though !?

It's just like a switch or socket plate but there's nothing on it.

To recap - I can make the wire connections with either 2 junction boxes OR connect each corrosponding wire individually with terminal blocks, these can be 15amp.

Underneath the blanking plate you can use choc-block, either three together or three singles. Don't forget to extend the earth wire which you should find attached to a terminal in the back of the box or, just possibly, on the switch itself.

when joining wires in a similar way for a plug socket do
I need to use 30amp blocks ?

Yes, use 30 amp blocks. If the socket is on a ring, there'll be two cables in there with three cores each. You have to extend them all. Or you can join them like to like in the box and add a third cable to your new socket - but make sure the original really is on a ring first.

can I use 30amp forboth

You can use 30 amp blocks for the lights too - if you can get them into the box!

 

[davelx]

If you use 30A blocks for the lights, which are probably wire in 1.5mm cable, you will likely need to double each core over to get the screw to grip firmly.

 

[BARCUD]

All the advise has been very helpful, thanx.

With the light switch, I intend to run the 2 x 3 core cables into 2 round 3 connection junction boxes, and then run the 2 cables to the switch from the 2 boxes. I intend to do the same with the wall socket. Hopefully I've got this correct !?

The 4 junction boxes will be easily accessible under the same floor board next to a skirting board.

If this sounds glaringly wrong please let me know.

many thanks, BARCUD

 

[sealeon]

I think i would only use one JB on the soocket and run it as a spur less conections to fail.Join the cables you got in the jb and add another single down to the socket maybe

 

[BARCUD]

SEALEON, this is what I did at first but wasn't sure if I was doing it right.

My idea was, take the two 3 core wires that run into the socket into a junction box, then take a spur down the wall and connect it to the new socket. BUT, would I then put the 2 lives into 1 connection in the box, the 2 neutrals into 1, and the 2 earths into 1 ? Then put the spur 3 core in opposite them ?

Except for upping the failure odds would fitting the 2 junction boxes be a problem ?

BARCUD

 

[sealeon]

sorry are we on about a light switch or a socket for a plug if as I think you are talking about a socket then one JB all browns together all blues together and all green/yellows together three wires per connection all the same colours
The two switch wires for the lights need two seperate JBs and extend them connecting the same colours together.
no problem using two junction boxes just more cable joins and two cables at the new socket
Dont forget your earth sleeving and make sure the powers off dead and checked before cos it hurts

 

[sealeon]

A three core cable usually means three insulated cables and a bare conductor[earth] old colours were red yellow blue and bare[earth]new colours ar brown black grey and earth[its a three phase thing]
A two core is two insulating cables old colours red and blck and a bare[earth] new colours are brown L and blue N and earth

 

[ban-all-sheds]

If you've got the floors up, and you're moving sockets and switches, why use JBs at all?

Replacing the appropriate sections of cable would be much better.

 

[sealeon]

If you've got the floors up, and you're moving sockets and switches, why use JBs at all?

Replacing the appropriate sections of cable would be much better.

This would be far better if it is possible

 

[BARCUD]

Okie Dokie, just replacing the wires with new longer wires would be the ideal solution BUT, I only have part of the ceiling down and NOT the floor boards up.

Great advise guys, thanx again, BARCUD

 

[sealeon]

Do you think its been made clear and understandable though

 

[BARCUD]

Yes I do think it has been made clear and understandable. I will find out today if it has as I'm doing the job this morning!

And yes I will make sure the power is off! Many years ago I put a screwdriver into a live wall socket and woke up at the other end of the room. Once shocked never again!!!

BARCUD