can you double up cable?

[mattysupra]

hi, im having a new extenstion built (garage)

There was a ring put in it ready (2.5mm with 32 amp breaker) that is laying under the floor ready to pull through.

However im now wondering if i should have had a larger supply put in with its on fuse board.

There is a car ramp going in and i think it pulls around 16amp on its own. Is this going to be o.k on 2.5mm ring? I asked a spark i bumped into and he said " double up the cable" ?? So i end up with 5mm? This dont make sence to me ?

so is this correct that if i join both ends up it will take more power and supply a seperate fuse board? Dont seem correct to me.

 

[LoveRocket]

You need to run extra cables from your main CU out to the extension.

 

[mattysupra]

you mean run extra cable from the CU if i have a seperate CU in there?

What about if i used the dedicated ring that was put in for there? The 2.5mm one? can this run a 16 amp motor?

 

[ban-all-sheds]

No.

You could cut the ring cable so you're left with 2 pieces the same length and supply the ramp that way, which I guess is what your electrician meant, but that's overkill as (assuming it's not run through insulation) a single run of 2.5mm² will be fine for a 16A load. And you could use the other length for a 20A radial for sockets & an FCU for the lights.

However im now wondering if i should have had a larger supply put in with its on fuse board.

Always best in the long run, IMO.

Is it too late to change?

Henley(s) to split the supply - switchfuse - SWA - garage CU with RCBO for sockets, MCBs for everything else.

hi, im having a new extenstion built

What did you put on the Building Regs application form about compliance with Part P?

 

[mattysupra]

No.

You could cut the ring cable so you're left with 2 pieces the same length and supply the ramp that way, which I guess is what your electrician meant, but that's overkill as (assuming it's not run through insulation) a single run of 2.5mm² will be fine for a 16A load. And you could use the other length for a 20A radial for sockets & an FCU for the lights.

However im now wondering if i should have had a larger supply put in with its on fuse board.

Always best in the long run, IMO.

Is it too late to change?

Henley(s) to split the supply - switchfuse - SWA - garage CU with RCBO for sockets, MCBs for everything else.

hi, im having a new extenstion built

What did you put on the Building Regs application form about compliance with Part P?

O.k thanks Ban.

The building regs bit, i paid my architect to sort out the planning paper work and submit to the council for me. Would that include Building Regs? The council are sending someone out to inspect the build in stages.

Or do i need to submit some other paper work?

 

[ban-all-sheds]

The council are sending someone out to inspect the build in stages.

That they are doing that shows he did apply for Building Regulations approval.

Or do i need to submit some other paper work?

No, but you do need to find out what your architect put on the application. If he said that the electrical work would be carried out by a qualified electrician, or by one registered to self-certify compliance with the Building Regulations, then you'll either have to do that or if you want something else see if the council will agree to a change.

 

[SUNRAY]

hi, im having a new extenstion built (garage)

There was a ring put in it ready (2.5mm with 32 amp breaker) that is laying under the floor ready to pull through.

However im now wondering if i should have had a larger supply put in with its on fuse board.

There is a car ramp going in and i think it pulls around 16amp on its own. Is this going to be o.k on 2.5mm ring? I asked a spark i bumped into and he said " double up the cable" ?? So i end up with 5mm? This dont make sence to me ?

so is this correct that if i join both ends up it will take more power and supply a seperate fuse board? Dont seem correct to me.

Yes you can double up a cable, as long as both parts are the same length and take exactly the same route. So 2 runs of 2.5mm can be used to supply a second CU in the garage fed by a 40A or even 50A MCB in the main CU but check to make sure there are no derating factors, including length to consider.