Junction Box

[osca]

Hi All

Me again

Can I install in a junction box instead of running a new cable to a 2 gang socket. The other cable is a bit hard to get to, so a junction box would save a lot of work and it could be located under the floor
Thanks
Tom

 

[Spark123]

Not really, all screw connections are meant to be accessable for inspection and testing. A JB under the floor isn't really accessable.

 

[oharaf]

More detail needed here, is this cable part of a final ring?

Do not really understand what it is you're doing

 

[electronicsuk]

Can I install in a junction box instead of running a new cable to a 2 gang socket. The other cable is a bit hard to get to, so a junction box would save a lot of work and it could be located under the floor

If what you're asking is effectively "Can I spur from a ring main using a JB?" then the answer is yes, but ONLY if the circuit you're wiring into is not already a spur. You should use a 30A junction box and wire your spur in 2.5mmsq.

Technically you shouldn't put the JB under the floor, but I have to confess to doing the same thing in my own house. After all, who *really* wants to install an ugly junction box where its visible?

 

[JohnD]

And when it somes loose and overheats, we hear the old "it's impossible to put it right because of the expensive laminate flooring/fitted carpet"

(search for the word "impossible" on Electrics UK and you'll find it's a common whinge)

 

[securespark]

John: I think you're being a bit unfair. It's not a common whinge at all.

It's VERY common!

 

[JohnD]

 

[bernardgreen]

Hunt the junction box ?

Look for the slightly discoloured areas of the laminated floor. Dig there.

Existing JBs under a floor are bad enough, putting a new one there is just not sensible.........

 

[pbar]

I understand what's being said with junction boxes where you can't see them, crimping being preferable, but -

1. How often do correctly fitted junction boxes come loose? I was at my old house almost 30 years and remember plenty of junction boxes in the loft for the upstairs lights. Not once did they come loose or cause an issue. There are plenty in my house now, still never had an issue.

2. On the assumption that they come loose on their own, surely the same must be true of everything as regards to terminal screws. Standard plugs for example. I can't remember one instance where I've had to undo a plug because it's come loose on it's own. I've got appliances a zillion years old, we all have.

3. Same point above for ceiling/wall lights, plug sockets, FCU's,etc. Never found myself having to go round tightening them all up.

3. Doesn't every house everywhere have junction boxes scattered around. I've just had an extension, junction boxes were used for the lights. And for the smoke alarms.

4. How many times have you guys got called out to a problem and it's been down to a junction box? Just wondering. And how many of those times has it been because they haven't been fitted properly.

Can't help thinking that this problem is minimal and that DIYer's are far better off using junction boxes as both DIYer's and electricians have been doing for years instead of attempting to crimp which can also be troublesome, especially for the DIYer.

I understand the views and potential issues. I've recently fitted an electric smoke alarm, junction boxed from a lighting circuit. It is under the floorboards upstairs, I made sure the boards are not too difficult to remove in the future and marked on them what lies beneath. And when the electrician fitted one elsewhere, he connected it the same way.

 

[davelx]

Hunt the junction box ?

Look for the slightly discoloured areas of the laminated floor. Dig there.

Existing JBs under a floor are bad enough, putting a new one there is just not sensible.........

Indeed, I've just added 7 new 2G sockets to my ground floor ring final, and in the process removed 2 underfloor JBs that were sitting on the slab and were showing clear signs of corrosion on the terminals, which were also not very tight, and three twisted and taped joints.

One of the JB's was directly under a socket, with plenty of slack to take the cable up the wall, but no, he'd put a JB in and a single cable to the socket! Whoever put that lot in was a right cowboy. But all fixed and to current regs now.