Redesigning the Junction Box

[Charlie]

Having just completed the wiring in my extension I couldn't help but question whether junction boxes have reached their optimum design in terms of saftey, convenience and commercial viability.

JBs are easy to wire up on the kitchen table with

- lots of slack cable

- plenty of illumination

- gravity working with you

- your elbows nicely supported

- cup of tea nearby etc....

But when you are up a step ladder with just a builder's lamp it gets trickier (well it does for me).

Does anybody have any ideas on how the design of the simple junction box could be improved?

I was thinking along the lines of:

- 2 earth and core wires all of equal length

- some sort of clamping system to secure the wires

- an anti-pull system for the sheathed cable (like you get in modern plugs)

I'm guessing ideas have already been tried but fail on grounds of:

- safety

- commercial viability I'm just interested in people's thoughts.

Charlie

[:::Jerry::::]

You need more practice then !...

IMO non of the above will help, some will even hinder, about the only improvement would be the use of a hexagonal head or recess to the conductor fixing screw - this would make it easier when working over head or vertically whilst still allowing the use of a brass screw.

[chris French]

In message , ":::Jerry::::" writes

Well, equal cable length would be nice, but I can't envisage how it would work with cables coming in from different directions.

Can't see the point in an anti-pull system, but sometimes when fiddling about with various recalcitrant cables, i think some sort of retainer by each terminal would be handy.

[John Rumm]

Try the MK ones, several times the price, but they do have some things in their favour. They have separate straight rows of smaller individual contacts for each wire, so less problem trying to get one in without another jumping out etc.

[bigcat]

fiddling

This can be done by 2 nodules; you simply pres the cable down round them in an S shape. A simple quick easy cordgrip.

But anything like this means more plastic and more money, the general direction of advancement is to make things cheaper.

NT

[a]

On a similar note, are there any small junction boxes around that will fit through a hole approx 60mm diameter? I rather foolishly laid one cable into a ceiling void (now plastered and painted) above the sink to supply 3 50W halogen spots in it - I couldnt find any junction boxes small enough to fit through the holes the spots required (63mm IIRC) so ended up using some 30A choc block and lots of insulation tape around it. I dont think it is dangerous as it is, just doesnt look very neat when you pull it out (hopefully it will never need working on again ;o)

[Dave]

... snipped

Yes, the 20A type from Ashley are really good quality and about 59mm diameter

[Lurch]

On Fri, 21 Jan 2005 14:58:11 +0000, Dave strung together this:

JB 201 from memory. Any wholesaler will have some, or an equivalent, if you ask them for small junction boxes. I've found the Ashley ones to be the most 'fall to pieces' proof though.

[a]

cheers - I'll seek out a wholesaler :o)

[Mike]

B&Q used to have the three way JBs with separate connection points per wire (12 in total). These were great and I never understood why they didn't do a

4 way by 3 wires and 6 way by two wires versions.

[Tim (Remove NOSPAM.]

By far the worst aspect about JB's is the non-contained screws.

These are just about on the table, downhill, but winding them out to get enough room to get 3 or 4 conductors under them whilst upside down *always* results in 1/2 turn too much and the screw falls out, never to be seen again, rendering that JB pretty much useless.

No doubt there are alot of bodged JB's about the country which have suffered the same screw-loss syndrome and the wires stuffed in joined with a choc-block or similar for the want of an errand screw....

Tim..

[Charlie]

Tim,

You're on my wavelength. That's precisely the reason I suggested a clamp system such as the one you often find for speaker cables.

The "anti-pull" mechanism I suggested came from the possibility that the clamps might not hold the cables securely enough. It also would help to hold each cable in place whilst you arrange and trim all of the wires.