using light fitting as junction box

[kentishman]

Hi there, I wish to add a light in my garage to illuminate the eaves storage area. My plan is to install a switch (probably a pull cord) for this new light in series with the existing garage light switch, so that the new lamp can be switched off when not in use, but if it's left on then the main switch will turn it off.

The existing garage lights are a couple of twin fluorescent tubes, two of these:

http://www.tlc-direct.co.uk/Products/MLTFL58W.html

that has plenty of space in its casing for additional connectors. It would be convenient to use this space for wiring the feed to the new switch and the return from the switch to the new lamp, rather than installing a separate junction box. Is this ok to do?

For connecting the sdditional cables I was going to swap the existing choc block connectors in the fluorescent for some Wago lever connectors like these:

http://www.tlc-direct.co.uk/Products/WA415.html

but there is no means of securing the Wagos so they would be loose in the fitting. Is this ok?

Thanks in advance

 

[PrenticeBoyofDerry]

You can secure wagos in wago boxes, could be a tight squeeze though within fluorescent fitting.
http://www.tlc-direct.co.uk/Products/WAGOBOX.html
How is your existing light terminated?

 

[kentishman]

Just checked the available space and it's not large enough for the Wago box. The existing light has choc block connectors that are not large enough for an additional cable ( the other existing light loops off them) so I would need to replace them with something anyway, even if it was larger choc blocks, but the Wagos are neat.

 

[PrenticeBoyofDerry]

So it's looped in with both live and neutral, then you have your switch cables and you have a spare terminal being used for live loop?
You want new light to be switched off by existing switch, are you happy that both light will need to be on for new light to operate?

 

[kentishman]

yes, there is no natural light in the garage so the existing lights are always on whenever it is in use.

 

[kentishman]

forgot to mention, there is no permanent live at the existing light, it is a switched feed.

 

[PrenticeBoyofDerry]

so what you need to do is at the loop in neutral at existing light take feed to the new light and connect at the the neutral terminal. From the existing switch take a feed from the switch live hopefully at L1 (not perm live at com) this will go to the pull cord and terminated at com and is a live conductor, then at pull cord terminate another live between LI and Live of new fitting.
Also run CPC/earths from existing switch to new fitting via pull cord switch..

This should then only allow the new light to come on when the existing one is on and when the existing light is switched off, it will kill the power to the pull cord switch therefore also new light .

 

[kentishman]

I was planning to take the existing switched live at the existing light and looping off that to the new switch.
My query was really if it's ok to house all connections for the new switch and light in the existing fluorescent fitting, or should I use a junction box? There is room in the fitting, but these new connections relate to a different light.

 

[Aragorn84]

Surely all you need to do is add another piece of T&E to the existing terminals, as though you were adding a third light, run that to your pull cord then on to the new light?

Why take the new pull cord back to the old light fitting at all?

 

[ban-all-sheds]

Surely all you need to do is add another piece of T&E to the existing terminals, as though you were adding a third light, run that to your pull cord then on to the new light?

I think that's what PBoD was describing - hard to be absolutely sure, as it was a bit jumbly.

Why take the new pull cord back to the old light fitting at all?

What's the difference between "add another piece of T&E to the existing terminals and run that to your pull cord" and "take the new pull cord back to the old light fitting"?

 

[kentishman]

The new switch will be in an opposite direction to the new light. The easiest and most convenient way of wiring the new light and switch is to take a feed from the existing fitting to a switch, then back to the fitting and then onto the new light. So a T+E from existing fitting to switch, then T+E from existing fitting to new light. If the junctions could be housed in the existing fitting it would be a neat soulution. If not, then I will install a separate junction box.

It's really whether it's considered ok to house connections in a light fitting that have no direct relation to that light.

 

[ban-all-sheds]

Ah - now I see.

That won't use any less cable than running a cable from the existing light to the new one, and then from the new light direct to the switch, so why not just do that?

 

[kentishman]

From the viewpoint of the internal garage door, the new light will be approx 4 metres beyond the existing light, but the new switch will be approx 2 metres this side of the existing light. The main garage light switch is not in the garage, it is in an adjacent utility room with hidden cabling until the existing light fitting.

So, one T+E (as feed to new switch and return, suitably identified) from existing fitting to new switch; then T+E from existing fitting, picking up the new switched live and a neutral, to the new light.

So as a cable run, it makes sense to make junctions at the existing light fitting.

 

[PrenticeBoyofDerry]

This way and you will only require one additional connector block in pull cord switch.
There is nothing wrong in making additional connection within enclosures of fittings or accessories, providing the it is related to the circuit of that fitting/accessory.

one switch two lights

• PrenticeBoyofDerry
• 14 Nov 2012
• 1

 

[kentishman]

I was thinking more along the lines of this...

Untitled

• kentishman
• 14 Nov 2012
• 1

(existing light connections omitted for clarity)

There is nothing wrong in making additional connection within enclosures of fittings or accessories, providing the it is related to the circuit of that fitting/accessory.

Ok, that's what I wanted to know, many thanks.