Opening Pandora's Junction Box

Some of you may remember when we were discussing how not to wire a junction box, I posted this:

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Well, I finally decided to tackle it. First problem - I can't open the box with all the earths in the way. And I don't want to leave them disconnected, since who knows what I'll find in the box and how long it will take to sort out. So, with a few bits from the junk box:

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No, I'm not going to claim that's compliant with regs, but at least they're all connected with screw terminals now. And I can get to the lid of the box. I'm still a little wary of what will be in it, but time to remove the lid:

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First problem - the corner of the box fell off when I removed the lid. And it's as big a mess as I expected. In fact it's worse - wire nuts? I thought they went out with the Ark.

The bigger question is what on earth all these wires do. It's pretty clear that this is just the lighting circuit. The two single terminals in the middle are the main live and neutral. There are only three internal lights and a security light in this part of the house, yet there are six switch drops that I can see, plus one more in the rose next to the box. And at least two of the lights don't use a switch drop, as there are two cables at the switch. The RYB cables are pretty clearly a two-way switch, yet the only two-way switching in the house is at the other end of the building back near the consumer unit, so it would make no sense for it to come here. So, a lot of investigating still to do. Of course, all the cables vanish under the loft insulation and boarding, making it very difficult to trace.

Mike

Reply to
Mike Humphrey
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It seems you need a box with 3 bus-bars in it, earth, neutral and live and another row of terminals to connect the individual pairs.

I've not seen one, perhaps Adam will assist where to get one?

Reply to
Fredxxx

Very simple to just make sure they're all connected properly and leave it.

NT

Reply to
tabbypurr

En el artículo , Mike Humphrey escribió:

eep.

The Shermans still use them.

I'd be tempted to sort out the earths (straighten them out and sleeve them, make sure it is actually earthed at the CU), tidy up the rest, use a new box, get rid of the wire nuts, make an attempt to trace and label wires.

Using DIN rail terminals in a box as per Andrew Gabriel's pic here might make life easier.

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Makes me wonder what other horrors are lurking.

Reply to
Mike Tomlinson

You can still get wire nuts and there is nothing wrong with them used properly, although there is room for error in the wrong hands.

Reply to
F Murtz

The best thing to do with that lot is to rip out the whole house wiring and start again. No doubt there is other hidden stuff as bad or worse. This is the sort of thing ends up killing people. DON'T try to bodge it up piecemeal.

Reply to
harry

Yes but if sme are redundant yet live it could be a nasty problem for the next time somebody drills a hole. What is needed is a nice sunny arm dayy disconnect them one at a time and have somebody with a ladder insserting buldbs and switching switches while the person near the box measures the continuity. If there are some that go to nothing take them out andmark them and when done and all good uns back on a nice busbar system and check everything works and does notgo bang. Always my favourite part! Sadly cannot do it any more. Brian

Reply to
Brian Gaff

I thing I would be temped to buy a load of 4 terminal junction boxes and wire off the lights as in this junction box drawing (whilst labelling up the cables).

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In the picture I can see 5 clear switch wire and cables off to light fittings. This would remove 10 cables from the jb and allow you to see what is happening with the remaining cables - I am pretty sure how the two way switching is working and that would remove another 3 cables (probably all of them if the remaining two are just permanent LNE).

Reply to
ARW

Rubbish - it just needs tiding up.

Reply to
ARW

A telecoms tone tracer might be useful. Ensure that nothing is live, disconnect a cable (having marked each cable with a letter or number and photgraphed and possibly a rough schematic sketch of what goes where in the box) attach tone sender then wander about trying to find the tone at switches/fittings etc

Reply to
Dave Liquorice

Or is at arms length under in a floor void trying to find where a cable goes only to find the open end of a simply cut through live T&E... BTDTGTTS.

Reply to
Dave Liquorice

Our first house was built in the early 70's looped at the rosettes, the pre sent bungalow built 1975 has a single neutral that links each rosette whils t the live is a strange cable I have never seen before which is a single li ve and earth with a red sheath on the live a green on the earth and an oute r sheath of red with a green stripe. This live loops to each switch com and from the switches a single switched live to the rosettes. All two way wiri ng is done with singles, the whole thing is a bugger when it comes to traci ng wiring. Cannot in either our case or with my daughters new build see any reason why to me the more common loop in at the rosettes was not used. In her case it has resulted in some switches which are part of a two-way switc hing to have 4 T&E cables terminating in the back boxes along with terminal strip connectors terminating the neutrals and a second for the earths all tightly packed behind the switch plate even on a 25mm deep box. I just cann ot see the logic of it.

Richard

Reply to
Tricky Dicky

Rubbish. I would just crimp some of it and fit a new box around it. Its easy to crimp stuff when you have a good crimper. 8-) Failing that do as ARW says and use a row of junction boxes and label them as to where they go for future reference. The earths need a bit of sleeving but they aren't exactly dangerous without it. Some cable clips would make it stable.

Reply to
dennis

My bedroom lightswitch has 4 T&E and 4 3&E but it is a 4-gang switch and the smoke detector circuit loops in and out at that point too.

It springs open like Zebedee having an orgasm if I loosen the faceplate screws.

Owain

Reply to
spuorgelgoog

I would have said this was a simple job for a multimeter or volt stick. It's easy to identify which cables go off to the light fittings so why not see which light switch control which light without disconnecting anything.

Reply to
ARW

If on your own there can be a lot of toing and froing to find and then verify single light controlled by single switch. Throw in some two way switching maybe with other switches that aren't two way and it's a nightmare. Or more than one fitting controlled by the same switches.

Easier if you have an apprentice and a pair of walki talkies... B-)

Reply to
Dave Liquorice

Agreed, I would screw the JBs to a baton above the insulation just in case you ever needed to work on them again.

I suspect that most of the lights in the OPs house were just run as a single T&E from every switch and fitting to a central point. It would not be the first time I have seen this done.

Reply to
ARW

Done that, but I use twin live and earth for the switch run, I had quite a lot left after I ran the five room stats.

Reply to
dennis

Not quite what you asked for, but how about?

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It obviously will not work for the strapper cable which needs a 6 terminal junction box.

Reply to
ARW

Well there's a reason I do not keep that in stock:-) You are capable of checking the cable you install is not twin live and earth - the apprentices are not.

Reply to
ARW

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