Taping into and Installing outside security light

DIY GUY · Nov 20, 2017

Thanks sidewinder & binky!

I have a double socket nearby where im putting the light. Does this mean I can just tap into the live on the normal double socket and the cable would be safe to bury?

Or would I need to wire the light to this then a link from this to my double socket

Sidewinder · Nov 20, 2017

You would need to feed it via a fused connection unit, similar to the above, you could use a switched version to give you isolation in case the outside light goes faulty and keeps tripping the RCD!

Please ensure that you do this safely, ensure that the power is off, and that all connections are sound, and that the cable is not damaged when installed.

An electrician doing this work would also test the circuit for safety, I suspect that you don't have the equipment to do the tests as required by BS7671?

DIY GUY · Nov 20, 2017

No I’ve no equipment to do tests.

Yes I’d do it safely and turn of power and would run the cable safely also behind wall or skirting.

So basically to do this job. I would have to put a fused switch relatively close by to my double socket, tap into the fused switch from my socket then run a cable from the fused switch to my new light? Does this sound correct & safe enough? What size of cable would I use to do both links?

DIY GUY · Nov 21, 2017

Could someone please simplify this for me please? Or is it really a job for electrician?

I thought it would have been a pretty easy job but seems so complicated now. Thanks

Tony S · Nov 21, 2017

Paul 1982 said:
Or is it really a job for electrician?

It is.

Doc Hudson · Nov 21, 2017

Paul 1982 said:
Could someone please simplify this for me please? Or is it really a job for electrician?

I thought it would have been a pretty easy job but seems so complicated now. Thanks

Some of the earlier methods you described could have been functional and legal. As BS7671 wiring regulations are non-statutory. And providing you are confident in you own work you could have fitted the light in such a manner. However no one on here could suggest the work would be safe as without correct testing there is no way of knowing. Just because something works does not mean it is safe.

The industry recognised method of confirming safety of any electrical alteration is to; (a) first double check the condition of the incoming supply, and its earth and bonding arrangements. (b) design and install the alteration including amending any parts of the existing installation to ensure they meet the current wiring regulations BS7671. (c) test the amended circuit, (dead tests and live tests) and document the test results on the appropriate electrical certificate.

Assuming all of the above tests are within the prescribed values for the type of circuit and protective device(s), then you could reasonably say that to the best of your knowledge it is safe to use and compliant with current regulations. As you say you have no test equipment then it is impossible for anyone here to give advice as to how you can prove the wiring you intend altering is safe now or after you have done the alteration.

It can be a very tricky balance offering advice over an internet forum as no one wants to encourage people to go dabbling around out of their depth with an invisible commodity that you cannot see or smell but can kill a healthy adult almost instantly. In my opinion the best solution to your situation is to amend the existing lighting circuit to include RCD protection, then add your new light to this circuit, but that would also need an RCD tester to verify the trip times to confirm safety. Also that type of fuse box is dated and it will probably require an external RCD, as you wont find you to fit internally. I think this work is outside of the scope of your abilities or correct tools & test meters.

Doc H.