To T or not to T

[Benway]

New outside lights at the back of the house.

Existing outside lights have their own dedicated RCBO.

Best practice to T into existing or run new cable to RCBO.

Cheers

 

[EngStudent]

Run a new cable back to the existing lighting RCBO? Or to a seperate RCBO?

If it's the former then you may as well take your feed from wherever is easiest/most convenient on the existing lighting circuit. If you can, provide means of isolation for the outside lights by way of a double pole switch; that way if you get moisture in the fittings which in turn trips the RCBO, you can isolate them causing minimal disruption to the rest of the house.

Edit: Didn't read the bit about the existing lights on the RCBO being all outside lights. As the poster below says, it will depend on existing load and your intentions for switching.

 

[thomo27]

I would think it depends on what load you have on the RCBO at the moment i.e. how many outside lights are on the RCBO and what wattage ?

Do you want the new outside lights to be switched with the existing or would the new lights be on a seperate switch (or are they switch by a PIR)

 

[Benway]

It was more of an ideological question.

The existing 6A RCBO has 2 26W lights. The new lights total 240W and are PIR'd but will have an isolation switch.

I would think it depends on what load you have on the RCBO at the moment i.e. how many outside lights are on the RCBO and what wattage ?

Do you want the new outside lights to be switched with the existing or would the new lights be on a seperate switch (or are they switch by a PIR)

 

[Benway]

The most convenient place would be about 200mm above the CU.....

If it's the former then you may as well take your feed from wherever is easiest/most convenient on the existing lighting circuit.