Unconventional Lighting Wiring

L

Lee Tickett

• Oct 25, 2016

• #1

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

-

Mentor

Nearly Esteemed

Arms

Joined

Sep 5, 2010

Messages

73,534

Reaction score

71,830

Location

cheshire/staffordshire

• Oct 25, 2016

• #2

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.

 

OP

L

Lee Tickett

• Oct 25, 2016

• #3

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

Staff member

Admin

Esteemed

Supporter

Joined

Jul 15, 2016

Messages

22,245

Reaction score

28,387

Location

Northamptonshire

• Oct 25, 2016

• #4

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

 

OP

L

Lee Tickett

• Oct 25, 2016

• #5

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

 

HandySparks

-

Mentor

Arms

Joined

Jul 22, 2011

Messages

4,333

Reaction score

2,656

Location

Hampshire

• Oct 25, 2016

• #6

Lee Tickett said:

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

Click to expand...

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

-

Arms

V.Nearly Esteemed

Joined

Jul 28, 2016

Messages

6,245

Reaction score

7,157

Location

Berkshire

• Oct 25, 2016

• #7

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

 

OP

L

Lee Tickett

• Oct 25, 2016

• #8

HandySparks said:

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.

Click to expand...

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

Wilko said:

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

Click to expand...

What's 543.6.1? Thanks

 

Wilko

-

Arms

V.Nearly Esteemed

Joined

Jul 28, 2016

Messages

6,245

Reaction score

7,157

Location

Berkshire

• Oct 25, 2016

• #9

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

-

Mentor

Arms

Joined

Jul 22, 2011

Messages

4,333

Reaction score

2,656

Location

Hampshire

• Oct 26, 2016

• #10

Lee Tickett said:

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

Click to expand...

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.

Lee Tickett said:

Do you have a diagram at all?

Click to expand...

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

 

OP

L

Lee Tickett

• Oct 26, 2016

• #11

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

-

Mentor

Arms

Joined

Jul 22, 2011

Messages

4,333

Reaction score

2,656

Location

Hampshire

• Oct 26, 2016

• #12

Lee Tickett said:

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?

Click to expand...

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

-

Mentor

Arms

Joined

Feb 25, 2011

Messages

9,894

Reaction score

6,432

Location

Cambridgeshire

• Oct 26, 2016

• #13

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.

 

OP

L

Lee Tickett

• Oct 27, 2016

• #14

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.