Simple practical question .... I think

[phil_ballard]

Hi all

I'm installing a lighting circuit in some (already present) 25x16mm rectangular plastic trunking (the sort with a snap-on cover) fitted high on my garage wall. What's the neatest, simplest and safest way to make cable connections? (e.g. to add cable down to switch etc) Coming out of the side of the trunking into a round junction box seems a bit messy.
Is there a tidy little product (or technique) for doing this? Is it permissible to use a (correctly rated) terminal strip inside a blank-covered pattress box, for instance - this would just look a bit neater alongside rectangular trunking (IMHO)

[BTW I know this sounds a half-baked question, it's hard to explain what I mean though]

 

[breezer]

why do you need choc bloc? (some where to connect to)

have a look at the "for reference" to see how to do it, there is no choc bloc / "extra" connections required .

 

[phil_ballard]

Yes I'd studied those, but the layout puts the switch (which is near the CU) a long way from the two lights (which are off in different directions). It would mean running a long cable to one of the lights from the switch, which I was hoping to avoid.

 

[breezer]

but if you dont run a long cable to one of the lights how will it work?

cost of cable is negligable.

nothing says you cant do the following

cu> switch> lamp 1 > lamp 2

it just means you can not run another light switch from this set up

 

[phil_ballard]

There has to be 1 long cable to each light, but the solution you describe in your reference entry means sending a switch cable out there as well - I'm not griping about the cost, it just strikes me it would be easier to send only the switched supply out there? Sorry, if I knew how to post a diagram, I would.....

 

[phil_ballard]

This is what I wanted to do ... sorry for cr*ppy diagram.

 

[AdamW]

These boxes are suitable for the switch.

This is a load of trunking accessories. At the bottom is a 25x16mm trunking Ceiling Rose. I am not certain, but it may be possible to fit a standard junction box "lid" on it and use a choc-blox inside it.

Surely someone must make a JB that fits mini trunking. I think I have seen them in Wickes even!

 

[breezer]

then why not do it as i suggested?

cu> switch> light 1 > light 2

 

[phil_ballard]

breezer, I'm certainly not doubting your solution, I was simply trying to avoid running an extra cable all the way out to L1, with all the aggro of opening trunking etc. (The cable would have to go out to L1 (say) then all the way back down the same trunking right past the Tee to the switch again:

And don't I still end up with a choc block (or something) to join the neutrals? (shown inside sw/box in diagram)

Is there some safety or other problem associated with the way I propose to do it?

 

[phil_ballard]

AdamW, thanks for these. No problem with the switch box, I have a suitable one already. I was just a little surprised that I couldn't get a more sightly junction box.

 

[ban-all-sheds]

I'm still struggling to understand the problem - in both your diagrams you've still got a cable running between L1 and L2, whether it has a junction box in it or not.

How about this:

T/E from CU to switch

2-terminal choc-block inside switch box for N & E

2 x outgoing T/E - 1 to each light - no need for a JB at the T.

And as for "all the aggro of opening trunking etc" - what aggro? Once started, the lids peel off very easily - bung in the new cables, put the lid back.

I'm sure I'm missing something, but I can't think what...

 

[phil_ballard]

Thanks Ban
The trunking is already in place (fairly inaccessible in some places) and the wiring from L1 and L2 is already there (not a continuous cable L1 > L2, but ends available where I propose JB). This is legacy of the previous incarnation. In my diagram of Breezer's solution, note there are 2 cables between SW and L1 - so I'd have to run an extra cable to L1.

What I was really after was whether there was anything fundamentally wrong or unsafe with the solution I diagrammed (1st diagram)? I agree your solution achieves the objectives too except that the present cables from L1 and L2 don't reach where I want the SW (not that you could have known that). If three's something harmful about having a JB then I'll rip out and do it as per Breezer's solution, but if it's permissible it's just a lot easier.

Thanks for all the advice chaps

 

[ban-all-sheds]

Nothing wrong with a JB, and nothing wrong with your JB consisting of a bit of choc-block inside a surface box with a blanking plate on it.

What sizes are the cables, and what is the rating of the MCB for the circuit you want to use?

 

[phil_ballard]

Lighting cables are 1.0 mm2, 6A MCB in a Volex garage CU with RCD

 

[ban-all-sheds]

AOK then