School Boy Mistake...

[hoojar]

I've made a school boy mistake and cut a cable too short when wiring up a socket in a backbox. the cables part of a new ring main and its already been platered into the wall.

this is what i'm thinking of doing instead of having to put a whole new cable in: add a connector to the cable to extend it and add a new backbox next to the current one. then put a blank plate on the old one and bobs your uncle.

does that sound like a decent solution or is there any reason i can't do it like this - regulations etc?

 

[flameport]

Can do - but why have a separate box with a blank plate? Just put the connectors in the box behind the socket. Or have an extra socket there if you need to move/add the backbox.

 

[hoojar]

i was thinking of using a blank and a new socket because its a bit cramped as it is in the backbox so i didnt think i'd be to fit a connector in as well. is there a specific type of connector i should use for this? there seem to be quite a few to choose from.

cheers.

 

[Taylortwocities]

If it is in a box that has a blank plate or a socket on the front then the connection will be accessible.

You could therefore use a 30amp piece of "choc block".

 

[electronicsuk]

Surely you'd be able to fit crimps in the existing backbox? Sounds a bit gash having an extra box with blanking plate to fix the mistake.

 

[Adam_151]

Putting aside the issue of how you are going to fix it, becuase others have already dealt with that...

Sorry if I'm teaching you how to suck eggs, but just incase you are trying to do what I've seen others do, I'll say teh following...

How short are you *trying* to cut the conductors?, it seems a common thing among DIYers to try and cut them exactly to the terminal positions, which is a bad move because if the front ever needs to be replaced and the replacement has live and neutral the other way around...

Try cutting them so that they reach the furthest corner of the box from where tehy enter and then some, and dress the cables in neatly as you push the front back and the excess conductor will lie flat directly behind the socket taking up very little room

 

[electronicsuk]

Some very good tips from Adam there. My personal preference is to trim back the outer sheathing as close as reasonable practical to the entry into the backbox. With a double backbox, I then take the conductors to the left hand outside edge of the box, bend them in a large sweep around my thumb, and then back the other way into the terminals. This always leaves plenty spare for future accessories with different terminal positions, and makes it very easy to pull the fittings away from the wall for maintenance.

 

[ColJack]

Some very good tips from Adam there. My personal preference is to trim back the outer sheathing as close as reasonable practical to the entry into the backbox.

always leave 10mm of outer sheath in the backbox.. that way you're sure that it's still inside the backbox when you push the fronts back..

With a double backbox, I then take the conductors to the left hand outside edge of the box, bend them in a large sweep around my thumb, and then back the other way into the terminals. This always leaves plenty spare for future accessories with different terminal positions, and makes it very easy to pull the fittings away from the wall for maintenance.

ah so it's you is it.. ?
sounds like a good way to trap a wire under a screw to me..

to me the backboxes need re-designing..
unless you actually use round conduit, then a round hole, who's midline is about 15mm from the back, is a bad way to get a flat cable into the box..

surely a square knockout at the back of the box would be better?

there's the problem then though of grommeting the hole.

 

[hoojar]

Thanks for the advice everyone. I've managed to get this working by..... turing the fixing on its side not ideal i know but its not in view anyway so its fine.

I have been cutting my cables way too short because I was afraid to squash them into the box. The first socket I did the wires came out of the connecters when I pulled them a bit, I'm using volex sockets and they seem to have a space at the side of the screw where the wire can go.

I've since been advised to double over the ends of the wire so I'm able to leave a bit more length on the wire and have confidence its not going to come loose when I press it into the box.

btw. what is the most likely result of a cable coming loose in the box? is this a fire hazard or is it more liekly to blow a fuse?

 

[Spark123]

If a live (line) conductor touched the back box it will either blow the fuse/trip MCB or trip the RCD
If the neutral touched then it should trip the RCD
The result of the conductors parting in a ring final circuit is that one leg of the circuit can be overloaded.
In a radial, downstream sockets wont work.

 

[seasickstevie]

But usually it's neither. They just get warm.

Which is why I like to leave a bit of spare in the box just in case when I come to replace/upgrade the sockets at a later date, I can cut the wire back a bit and re-terminate with fresh copper.

I always double over the cores.

(No not the Irish singers )

 

[electronicsuk]

ah so it's you is it.. ?
sounds like a good way to trap a wire under a screw to me..

Never happened so far...