Electrical Advice

Windofchange

Hey all,

Doing some home renovation stuff at the moment and I want to run a power supply up into the loft. At the moment I have knocked through a wall and have the back of a double socket exposed. There are two wires running into this, so my understanding is this is on a ring main.

What I want to then do is add two sockets.

First socket is going to be on the other side of the wall in the new room I am making. I would then like to run a second socket up into the loft so I can convert this into a games room.

My question is around the maximum wiring run in the house. It is a two level maisonette - hallway on the ground floor is where the fuse box and mains feed is. We then have the first and second floors with the attic above that. I have read that you can only have 50 metres of cable in your circuit. I would be adding I guess about 3 metres going up into the loft and then 3 metres coming back down - I'm happy to have the double socket in the loft directly above so don't need to run additional cable around.

How do I know whether I will exceed this 50m rule?

phill99

I know this is a moneysaving site, but truthfully, for this I think you would be better off getting someone in. As You are extending a circuit, this needs to be tested and a minor works certificate issued.

Windofchange

Yeah I am kind of going along that thought process - I have an electrician hopefully coming out today to take a look, but I like to understand these things too even if I don't end up doing the work myself. How do you know if you will be overloading the circuit with your extra wiring loom?

Mr.Generous

50mtrs is a lot for a house if its a typical size house you will be under that. Large properties will be set up with 2 ring mains, sometimes a separate ring for the kitchen. If there is enough slack to get one existing cable to the new socket it's easily achievable. make sure you maintain ring integrity. If not you are looking at joining a cable, not something I'd do unless you are qualified. Its going to need testing anyway so get a price from a couple of sparks.

Windofchange

Cheers guys. Got a sparky coming this afternoon to take a look. I guess I can quiz him a bit about the cable length, but I like to go into things with a bit of information about what I am after. I don't think it is going to be too big a job - maybe an hour of his time.

phill99

Windofchange wrote: »

. How do you know if you will be overloading the circuit with your extra wiring loom?

You wont. He will.

Owain_Moneysaver

Windofchange wrote: »

I have read that you can only have 50 metres of cable in your circuit.

Where?

You can have a circuit as long as you like provided the protective device trips quickly enough and the volt drop is within limits.

Owain

Ectophile

Windofchange wrote: »

Yeah I am kind of going along that thought process - I have an electrician hopefully coming out today to take a look, but I like to understand these things too even if I don't end up doing the work myself. How do you know if you will be overloading the circuit with your extra wiring loom?

You can't overload it, because it will be on a circuit breaker. Of course the breaker might trip, but that's unlikely. Most rings use a 32A breaker, so that's an awful lot of small appliances. A few years ago, houses were wired with all the sockets on one ring, and that worked fine.