Connect Brown+Black to Brown+Blue? Earth leftover. . .Hmmm

[Dom1980]

Hi All - I'm connecting a PIR outdoor light fitting.  - Which I want to connect to another wire leading to the main power supply. 

- This main wire only contains Black and Brown wire colours within only. (No earth) 

Therefore I would like to know , from the PIR Light, which has 3 internal Wire colours - Blue, Brown, Yellow/Green - 

- I connect the (LIVE) Brown to Brown . . .

- Then do I connect the Black ? (to the Blue - Neutral ? ? ?) 

- And then what should I do with the Yellow/Green left over wire , insulation tape ?    _ I thought this would be a doddle  , but the jury's completely out on this one.

BIG Thx to anyone for jumping in, maybe saving my life

 

[Sharpend]

When you say main supply, where to main supply? Light switch, socket or consumer unit? 

 

[Geoff1946]

If your light fitting has an earth (green/yellow) you can't just abandon it. You must source an earth connection from your house wiring. 

Black and brown are not normal colours to find leading to a light, so it's anyones's guess. However if there was  a working light there before they must be live and neutral which could be determined by testing. There is a sporting chance that it's mixed old and new standards, brown live, black neutral, but as I say guessing!  It should be tested.

Your real issue is the absent earth. Do not install that fitting without finding an earth. If that's too difficult you may be able to find an alternative double insulated fitting which doesn't need an earth.

 

[SPECIAL LOCATION]

Black and brown are not normal colours to find leading to a light

Unless someone has used some 3core+E, and just cut off the cores they didn't think important..

e.g.

Brown / Black / Grey 

and Mr DIY thinks he has seen Brown and Black before when wiring up plugs etc..

But the Grey is just confusing so cut it off!

I was changing a CU back at the start of November..

Whilst doing a few sample inspections & tests for my EIC..

I found that, excluding the supply feed from the CU which was Rd/Bk T&E...

ALL of the rest of the lighting circuits were wired in RYB+E..

Dunno if the builders electrician had just acquired a job lot of 3core+E  that they wanted to use up..

or if it was a specific contractors method to provide L,N & SwL everywhere!

I think we would benefit from a photo of the OP's actual wiring?

:C Guinness