Extending the lighting circuit

[eco-tech]

Eve,

Am doing a 1st fix on a new lighting circit in a extenstion. The problem is the house is concrete block and the only way i can get to the ground floor and 1st floor lighting circuits is near the C/Unit.

What i need to know is can i jst add the new circuits to the Breakers that are in the c/u (two circuits 1 for the grond floor extension and 1 for the 1st floor extension) Or do i need to use a new breaker foe each one ?

The loading is good and will be protected with a 30ma rcd on each circuit.

help please ?

 

[Spudnik]

Ideally into a spare way for the extension lighting, which can be for upstairs and downstairs.

If not, put them into the correct existing MCB's for up and down.

 

[eco-tech]

Yeh i thought the ecisting breakers would be ok, but am unsure if could have two circuits out of one breaker etc.

 

[Risteard]

Yeh i thought the ecisting breakers would be ok, but am unsure if could have two circuits out of one breaker etc.

You can't, but only because it's impossible.

Putting them in the same breaker makes them, by definition, one and the same circuit.

 

[Jason Smith]

you could have a sub main fed off the main cu to feed the extension, this will use one way from the exisitng board, and will provide you with as many new ways the demand on the extension will alow, you can often get a five way board in the same cupboard as the main board.Just a thought for you .

 

[Sintra]

You can't, but only because it's impossible.

Putting them in the same breaker makes them, by definition, one and the same circuit.

Putting them in the same breaker makes it a parallel circuit which has to meet certain criteria.
ie. same length on each circuit, same load on each circuit and same cable csa on each circuit.

 

[eco-tech]

So if i put a new c/u in, with room for breaker's for the lighting (both circuits) this will be good ?
Also do the same for the sockets. A new ring main for the extension ?
Then 1 for the smoke etc ?

This house bashing does my head in grrrrrrrrrr.

 

[Sintra]

Yes new cu with enough ways for all circuits as you have stated sounds fine.

 

[eco-tech]

Thanks chaps.