Wiring set up for bathroom ceiling

[WabbitPoo]

Above our bathroom we have wiring run for all these items:

Downlights (3) (switched at pull switch)
LV light over a shelf (switched at pull switch)
Shower fan and light (switched at pull switch)
Two electric razor points
A loft light
A powered aerial booster/splitter

not to mention the lighting ring for the top floor as well.

At the moment there are seven junction boxes and cables everywhere, and so I am looking to tidy it all up.

I know what all of the wires do and I have so far labelled them all.

Given that you can only fit say, three wires comfortably in a given junction box terminal, I can see why the need for so many boxes. I was wondering if the easiest (?) way to tidy them would be to mount a ply board on the rafters and to run cables up to it and through to the JBs mounted on the front. That would allow me to clearly label each box and to get at them as and when needed.

Alternatively, is there a clever way of joining so many devices from just two points (ie one switched and one live ie the fan live feed)?

Clear as mud, I am sure.

 

[felix]

I'm all in favour of grouping junction boxes together. It's neat and it makes access simple. The question now is how many do you need.

You should daisy chain your downlights so that only one cable comes back to the junctions. This gives you a total of four unswitched loads and three switched loads. As an absolute minimum you are going to need six terminals: live, neutral, earth and three switched lives.

In practice you need more. You cannot reasonably expect to get eight lives and neutrals into their respective terminals, still less eleven earths! I think you can do this with three boxes daisy chained in line. In each one you have live, neutral, earth and switched live terminals. That's the three switched loads taken care of.

So far so good. In two of the boxes you have three cores in the live and neutral terminals and four in earth. The end box has one less of each. If you get decent boxes you will easily get an extra unswitched cable into the first two boxes and two extras into the last one. The maximum number of cores in any one terminal will be five.

Another option, possibly more elegant, has the power coming into the central box and splitting off both ways. Your unswitched cables now go in the end boxes. You still have the same number of cores in your terminals.

 

[WabbitPoo]

Thanks very much for decoding my post! I'll have to draw it out as you describe, but I ma glad its OK to mount the JBs as I described. Should make it tidier, if nothing else.

 

[ban-all-sheds]

If you want tidy, consider the use of DIN-rail mounted terminals, with jumper links to interconnect as many as required, or DIN-rail mounted distribution blocks, on a rail fixed inside a box.

 

[WabbitPoo]

I DO want tidy, but a quick look at them elsewhere on the web makes me think they are beyond my skill set (looks scarily like a CU to me!)

Quite happy with JBs in general, just a pain with so many wires involved.

Good tip, though - thanks.

 

[ban-all-sheds]

Henley blocks??