Moving electrical outlets

[iaingray741]

Hi All,

Hopefully someone can give me some advice here...

I have recently moved into a fairly old house (60's build), it's been an older couple that's lived there recently. It seems at some point all the electrical outlets have been moved up to about 1.2m from the height of the floor, I guess for accessibility.

I've like to move these back down to about 450mm, however a lot of the cables have been shortened and there's not enough sack to do so.

Some of the cables I'll be able to replace, but if I cannot, what's the best way for me to extend the cable? Terminal block, solder, crimps, etc?

Any input would be appreciated!

Thanks

 

[ban-all-sheds]

Assuming that you'll be plastering over the old socket box, and therefore any joint, you may not use a terminal block, and soldering is never appropriate. If a joint is to be inaccessible then you must use either a maintenance free JB such as the Ashley J803:

https://www.tlc-direct.co.uk/Images/Products/size_3/ASJ803.JPG

or crimps, but you need to use a crimper like this:

not like this:

If you are going to crimp, you should also get some heat-shrink tubing, in two sizes - sleeve each core individually, and then another piece over the whole lot, completely covering the unsheathed section. Staggering the individual joints can make this easier. Or use a choc-box to enclose all the joints and unsheathed section.

 

[sparkwright]

Firstly, why can't you replace all the cables?

Presumably the cables in question come from above, as they are too short, so I'm guessing some damage will have to be made.

Line crimping then heat shrink is about the only acceptable way for a DIYer to extend cables within a wall, but bearing in mind it would appear the wiring is about 50 years old it would be wise to replace the lot and have a proper job.

 

[sparkwright]

Assuming that you'll be plastering over the old socket box, and therefore any joint, you may not use a terminal block, and soldering is never appropriate. If a joint is to be inaccessible then you must use either a maintenance free JB such as the Ashley J803:

Presumably to extend a cable in a solid wall, one would have to remove the old back box, and use crimps - perhaps in staggered formation, so the cable remains a similar width.

I mention this so one has a good idea where the cable is buried in the wall, ie dead in line with where it can be seen disappearing from the new socket box.

I would imagine a joint within an old back box or within a junction box would be misleading for anyone trying to assess the whereabouts of a cable before drilling a hole.

EDIT. Goddamn it, he's edited his original post since I wrote this...

 

[JohnW2]

Presumably to extend a cable in a solid wall, one would have to remove the old back box, and use crimps - perhaps in staggered formation, so the cable remains a similar width. ... I mention this so one has a good idea where the cable is buried in the wall, ie dead in line with where it can be seen disappearing from the new socket box. ... I would imagine a joint within an old back box or within a junction box would be misleading for anyone trying to assess the whereabouts of a cable before drilling a hole.

I think you may be expressing unnecessary concerns - don't forget that the safe zone is as wide as the new socket's back box.

Kind Regards, John

 

[sparkwright]

That was in the back of my mind, but then why does this forum panic about 'unrelated' cables being in the same zone?

If you see what I mean?

 

[JohnW2]

That was in the back of my mind, but then why does this forum panic about 'unrelated' cables being in the same zone? If you see what I mean?

The problem with an 'unrelated' cable that is not connected to, or joined within, an accessory is that it would often theoretically be possible to remove the accessory (together with any wiring that was actually 'connected to' it), leaving the 'unrelated' cable without a safe zone.

Even an 'unrelated' cable 'passing through' the backbox of an accessory is not totally foolproof. The accessory could be removed and the backbox (with 'unrelated' cable going though it) 'plastered over', again potentially leaving that cable without a safe zone.

Kind Regards, John

 

[sparkwright]

By that token, going back to my original query, what if the new back box was removed and placed a few inches the other way (for whatever reason) meaning the new socket and the cable still remains in the safe zone, but NOT the hidden joint within the old back box?

 

[JohnW2]

By that token, going back to my original query, what if the new back box was removed and placed a few inches the other way (for whatever reason) meaning the new socket and the cable still remains in the safe zone, but NOT the hidden joint within the old back box?

I suppose it depends upon what you mean by 'a few inches'. It it is more than the width of the box, I can't see how the cable could remain in a safe zone.

Whatever, I still think you're probably worrying unnecessarily. My understanding was that the OP simply wants to reposition the socket directly vertically below its present position - in which case one has the whole width of the backbox to play with for a joint. ... if the back boxes are the same size and directly aligned with one another, any joint within the old box will inevitably be within the safe zone created by the new socket/box.

Kind Regards, John

 

[sparkwright]

By that token, going back to my original query, what if the new back box was removed and placed a few inches the other way (for whatever reason) meaning the new socket and the cable still remains in the safe zone, but NOT the hidden joint within the old back box?

I suppose it depends upon what you mean by 'a few inches'. It it is more than the width of the box, I can't see how the cable could remain in a safe zone.



Kind Regards, John

An example would be a new double box has the cable passing through the top extreme left knockout. It's then decided the box could do with being to left a bit. So the box is removed, a chase is made in the wall, and now the cable passes through the top extreme right knockout.

Meanwhile, this has pushed the hidden joint above out of the cable zone.

 

[JohnW2]

An example would be a new double box has the cable passing through the top extreme left knockout. It's then decided the box could do with being to left a bit. So the box is removed, a chase is made in the wall, and now the cable passes through the top extreme right knockout. Meanwhile, this has pushed the hidden joint above out of the cable zone.

I don't really know why you are coming up with all these hypothetical scenarios. AFAICS, all you are saying is that if you don't 'line up' the two boxes appropriately, a cable might not be in a safe zone once one of the boxes becomes 'hidden' - but that's just obvious! Assuming that the old box is not movable, one obviously has to install the new box such that cables from the (visible) new box will remain within the (new box's) safe zone on their way to the old box (which will become hidden).

Kind Regards, John

 

[sparkwright]

The only reason I have come up with hypothetical scenarios is because you have, that's all.

That was in the back of my mind, but then why does this forum panic about 'unrelated' cables being in the same zone? If you see what I mean?

The problem with an 'unrelated' cable that is not connected to, or joined within, an accessory is that it would often theoretically be possible to remove the accessory (together with any wiring that was actually 'connected to' it), leaving the 'unrelated' cable without a safe zone.

Even an 'unrelated' cable 'passing through' the backbox of an accessory is not totally foolproof. The accessory could be removed and the backbox (with 'unrelated' cable going though it) 'plastered over', again potentially leaving that cable without a safe zone.

Kind Regards, John

 

[JohnW2]

The only reason I have come up with hypothetical scenarios is because you have, that's all.

That was in the back of my mind, but then why does this forum panic about 'unrelated' cables being in the same zone? If you see what I mean?

The problem with an 'unrelated' cable that is not connected to, or joined within, an accessory is ....

I don't think that's fair! As your quote illustrates, I merely responded to your question as to why "the forum panics about 'unrelated' cables in safe zones" - and I really don't see what that scenario has got to do with what we are (meant to be!) talking about in this thread!

Kind Regards, John

 

[sparkwright]

Let's try this from another angle then.

Isn't joined wires together in an old back box, then trying to applying heat shrink going to be difficult?

And doesn't there seem to be something 'messy' about it?

Removing the box, and joing with crimps in staggered formation, with heat shrink, and even some oval conduit if room has got to be the better way.

 

[JohnW2]

Isn't joined wires together in an old back box, then trying to applying heat shrink going to be difficult?

Possibly - although there is 'no limit (within space limitations!) as to how much of the new cable could be inside the box.

And doesn't there seem to be something 'messy' about it?

Yes - I would never (knowingly!) have 'plastered-in' joints of any description in my house!

Removing the box, and joing with crimps in staggered formation, with heat shrink, and even some oval conduit if room has got to be the better way.

As above, as far as I am concerned, that is also 'messy'. For me, at least (all of) the buried part of the cable should be replaced - with no 'buried joints'.

Kind Regards, John