Junction Box on Ring Main

Hi

I've read in a few places on the forum that you shouldn't use JBs to extend ring circuits.

Why is this?

Any reference site or book I look at suggests two methods - using exisitng sockets, or using junction boxes.

I've tried searching on the forum to find an answer but can't see the wood for the trees so would be grateful if someone could explain.

Thanks
Scott

the trouble with junction boxes is they are supposed to be acessilble

this ofc raises the question of how accessible is accessible. and this is something the regs themselves don't answer though the electromafia organisations have thier own definitions that tend to err on the side of strictness.

So there's nothing inherently dangerous about them, it's just about where they're positioned?

I only need to use one and it will be under the floorboards one joist away from the wall. Is this under the umbrella as "accesible"?

Thanks
Scott

i would say no because its under the floor,
what happens when you fit a carpet, or other similar floor covering? do you Have to use a jb? can you not pull a cable back and into new socket, then from new socket back to old one, still stays in a ring but no jb, and less joints

as i said the wiring regs have no hard and fast rules for how accessible it is

the electromafia organisations don't consider under floorboards accessible. Many sparkys do provided its well marked and there isn't something like laminate flooring on top.

finally if noone knows its there noone can fail it

Breezer - no, unfortunately there's not enough cable already there to go between the sockets.

Thus easy option would have been to join a piece of cable on to run to the new socket rather than refeeding from the old.

But, erring on the side of caution I've decided to replace it with a single piece of cable.

Had a JB been acceptable then I would have saved myself the effort of refeedingthe cable but I've 50% done it now so almost there!

Thanks both for the prompt replies.

Scott

Scott, JOB's should only be used as a last resort and in an ideal world should be reasonably accessible, however under a floor board would be considered as "reasonably accessible"

What all these amateur sparks fail to realise is that the OSG is designed primarilly for use on New Builds. Obviously there is cross over to refits etc, but the the OSG is a small book and cannot possibly cover all scenarios.

There are certain situations where JB's are the only solution, so if you have to use one, simply make sure you do a good job, all terminations are clean and screws tight, and the JOB will not be effected by external environmental influences, such as damp, extremes of hot and cold, insect attack (difficult one I know) and also vibration, as this last one will have a direct impact on the terminations.

Installed correctly a JB will last the life of the installation, regardless of what some scaremongering nimbies will tell you.

That makes a lot of sense.

I've actually replaced the cable now with a single piece, which wasn't too much work in the end but this is the first room in the house to be decorated so I'm sure I'm going to come up against this again as I move onto the next rooms.

Many thanks for all the advice.

Scott