2 junction terminals from ring mains?

[BigJim]

Hi,

I have both wires of the ring mains running under my floor boards. I want to put 2 double sockets in the room, each on a different wall. I understand that I shouldn't really run 2 spurs from a single junction terminal so I need to use two junction terminals. Question: should I put one junction on one wire of the ring mains and the second on the second wire of the ring mains to prevent the 2 junction boxes being too close together?

Your advice would be much appreciated!

Cheers.

 

[TicklyT]

Somebody who knows what thet are doing will probably be along in a minute....
Why not extend the ring though. Break one cable, and add your new sockets from one end, and link back to the other end.

 

[pcboffinuk]

BigJim,

There are a couple of issues here,

The main issue with rings is to try to balance an equal load on both legs, although in practise it is not too important unless one leg has all the load on it.

The more important issue for you is that you can't put junction boxes under the floor unless they are 'accessible', which is generally taken to mean not under carpet or laminate floor (unless there is a clear trapdoor). This is because screwed connections can work loose and may need to be checked in the future. The only accepted way to join cables in an inaccessible place is to crimp, but this can take some practise to do correctly.

Not sure how close the under floor wiring is to your socket location? The best option if possible would be to cut the wire (with the power off!), and insert the socket directly into the ring. If there is not enough slack you could put one side in and perhaps run new cable along to the next socket in the ring, or crimp to the remaining existing wire under the floor.

Hope that helps, but feel free to ask about anything you are unsure of, you will always receive good advice here.

Regards

Gavin

 

[dunny]

I have seen this many times about inaccessible JB's but all the houses I have lived in , including ones completely rewired by qualified sparks have ALWAYS had JB's under the floor!!!

Has it always been the rule is this one of thos things that open to 'intepretation' !!!

D

 

[BigJim]

Thanks a lot for the replies, it sounds like I should get an electrician in to do the job properly then as there is no slack in the wires of the ring. I was goingf to put the junctions on a plynth from a joist for stability. Is the advice about not putting junction terminals under floor boards just best practice or a serious no no?

 

[BigJim]

The two sockets are in opposite directions too so it's not really feasible to extend the ring for them both. Thanks for the advice so far!

 

[davy_owen_88]

All joints not classed as permanent MUST be accessible. Accessible isn't clearly defined within the regs which is why lazy people often put them in places not regarded as accessible when something actually goes wrong.

If there was a fault and your lights/sockets failed, how would you feel having to empty a room, rip up the flooring and then pry up some floorboards until you find the JB?

 

[dingbat]

I have seen this many times about inaccessible JB's but all the houses I have lived in , including ones completely rewired by qualified sparks have ALWAYS had JB's under the floor!!!

Qualified does not mean competent. Neither does 'experienced'.

The majority of so-called electricians working in the domestic market are neither qualified nor competent... but may be very experienced at hiding junction boxes!

There is no excuse for inaccessible junction boxes on a rewire.

 

[dunny]

The majority of so-called electricians working in the domestic market are neither qualified nor competent... but may be very experienced at hiding junction boxes!

Thats rather a bold statement !!

However if thats true thats very scary!!! - I have given these guys thousands of quid over the years. Never had any major issues but might as well have done it myself then??

D

 

[davy_owen_88]

What dingbat means is, anyone can do a 5 day course and say they are 'qualified' but this doesn't stop them doing jobs to a ****-poor standard. Same applies to DIY'ers only in reverse, there is nothing stopping them doing jobs to a very high standard yet being totally 'unqualified' in the eyes of most people. This is where the main word 'competent' comes into play - you can be qualified and still be incompetent and vice versa.

 

[BigJim]

So the overall advice then is not to use jbs but to get someone in who can crimp me a proper junction and feed out a couple of spurs to my sockets?

 

[davy_owen_88]

Pretty much, but most sparks will try to extend the ring not run them as spurs and most will try to replace the cables instead of crimping, but as a last resort crimps and spurs will do the job you want.

 

[BigJim]

Had another thought on this that might affect the advice about JBs under floorboards. I'm not actually going to cut the ring mains wire, I'm going to remove the insulation and position the wires into the JB before adding a spur (or two? back to the original question). Shouldn't this minimise the risk of a problem with the ring mains and therefore make it OK to use this? The most likely problem to arise would be to the two new sockets I am adding but that's going to be a risk whatever.

If I stabilise the JB by screwing to a plynth attached to a joist, I am minimising the risk of screws becoming loose aren't I? I'm trying to understand if this is something I can do myself or if I've got to shelve out £100 for someone else to do 'professionally'.

Cheers for the input so far, very helpful.

BigJim.

 

[dingbat]

What dingbat means is, anyone can do a 5 day course and say they are 'qualified' but this doesn't stop them doing jobs to a p**s-poor standard. Same applies to DIY'ers only in reverse, there is nothing stopping them doing jobs to a very high standard yet being totally 'unqualified' in the eyes of most people.

Nope. Mostly I'm referring to the guys who have been doing wiring work for years and years and years and regard themselves as electricians. You know the ones; no test kit, no knowledge of the actual regs and testing consists of switching things on and off. Their years of experience sometimes show, with good quality (if non compliant) work, but more often than not they started out sloppy and then started to cut corners.

In contrast the 'five-day-wonders' are concerned enough to pay good money to go on courses, buy test equipment and then pay more good money to be assessed by a third party, which can be a daunting experience.

I'd rather have my work done by somebody trying hard to comply, than by somebody who isn't even aware that there are regulations.

This is where the main word 'competent' comes into play - you can be qualified and still be incompetent and vice versa

For a working definition of competence you need to refer to Reg 16 EAWR 1989.

 

[dingbat]

So the overall advice then is not to use jbs but to get someone in who can crimp me a proper junction and feed out a couple of spurs to my sockets?

The correct way to go about it is to either extend the ring or take a spur from an accessible location. The best bet is to make your modifications at existing sockets.

Yes, it may involve making good, but you'll have all the pleasure of knowing you've done it right while you're busying yourself with the Polyfilla!