Unconventional Lighting Wiring

[Lee Tickett]

I'm wiring a few lights in a brand new office and would like them all switched from a central point. Some then have PIR sensors others not.

Rather than having a traditional ring then bastardising a cable to "return the live back to the switch then the switched live back to the light" I would like to switch the live at the source. I have attached a sketch which I hope roughly depicts what i'm looking to do.

Is this a complete no go or is it recognised/allowed?

Thanks

 

[telectrix]

T/E's from CU to a 2 gang switch. break the L's with the switches . no need for JBs. if you need perm. L's for the sensors, then use 3c/E cables.

 

[Lee Tickett]

Thanks for the speedy reply. How would you suggest wiring multiple T/Es from the CU? Fair enough with the neutrals/earths, but would you about the lives? Could possibly squeeze 2 into the MCBO, but what if we extrapolate to 3, 4, 5, 6 etc...

 

[westward10]

How many circuits are you considering, they should be on individual devices. Could wire from CU using singles in conduit.

 

[Lee Tickett]

Initially 5 individually switched lights (was looking at the MK grid style boxes for the switching)

 

[HandySparks]

Initially 5 individually switched lights (was looking at the MK grid style boxes for the switching)

So run a cable from DB to grid switch box. Line into first switch, then short jumper to next switch, etc. Use a 6 way push in Wagos to split your neutral and earth. Just make sure your backbox is deep enough.

 

[Wilko]

What they said
And apologies if it sounds too basic, but don't forget 543.6.1

 

[Lee Tickett]

So run a cable from DB to grid switch box. Line into first switch, then short jumper to next switch, etc. Use a 6 way push in Wagos to split your neutral and earth. Just make sure your backbox is deep enough.

Spot on, that sounds exactly like how I pictured it. It is acceptable to have the neutral and earth wagos in the grid switch box?

Do you have a diagram at all? I am going to try and draw something up just to make sure I fully understand. Thanks

What they said
And apologies if it sounds too basic, but don't forget 543.6.1

What's 543.6.1? Thanks

 

[Wilko]

Ok.
543.6.1 is a regulation in BS7671, saying "where overcurrent protective devices are used for fault protection, the protective conductor shall be incorporated in the same wiring system as the live conductors ..." . If you are not familiar with BS7671, it's a real page turner .
As I'm also Safety Sam, please look up safe isolation techniques and 2 pole voltage testers. It is very dangerous to just turn off an mcb and assume that all will be well. Cheers.

 

[HandySparks]

It is acceptable to have the neutral and earth wagos in the grid switch box?

Entirely acceptable, although some electricians may frown on it. Just make sure that there's enough space so you don't have to cram the wiring in.

Do you have a diagram at all?

No. You need to be able to do your own diagrams for each installation, taking into account the requirements of the wiring regs.

 

[Lee Tickett]

Last question hopefully. For simplicity sake I'm now considering double pole switches (switching both live and neutral). Anything in the regs or reason why this may not be a good idea?

 

[HandySparks]

Last question hopefully. For simplicity sake I'm now considering double pole switches (switching both live and neutral). Anything in the regs or reason why this may not be a good idea?

I don't see how this makes things simpler. You'll have to daisy chain the neutral along the switches as well as the line.

 

[Richard Burns]

Wiring DP switches is going to be a lot more fiddly than SP switches.
No regulations reason why not but just convenience.
Connect all neutrals in wago vs connect each neutral to its own separate terminal and wire link wires between each terminal.

 

[Lee Tickett]

Thanks guys, really helpful. I think I got caught up thinking about fitting the wagos etc in the backbox, but I guess i'm just going to give it a go!

I had similar fun when planning a rewire of a CU with DIN rail energy monitors (I couldn't find a photo of anyone having done it before, so struggled to work out the best approach) but it worked out well in the end.