what is correct rating for an electrical circuit breaker

[stel]

I am running a 2.5mm2 steel armoured cable from my house mcb board to the garage in a ring main,its about a 10meter run, and it will serve some radiators and television av equipment,

it will have an mcb rcbo for the circuit but what 1 do i use,20amp or 32 amp....

[raysparx1]

If you are running a single 2.5, it cannot be on a ring main as that requires a feed and a return, what you would have to have installed is a "Radial" circuit ie: 1 cable feeding one or more sockets, this should be rated at 16 or 20 amps, but do you realise that this is illegal to be done as a DIY job ? it should be done by an electrician registered for "part P" of the building regs.Ray

[buildersmate]

Or else you DIY but make a Building Control application for inspection of the work you have done. About �120 for the BC application.

[stel]

thanks for the response,i know i said I in my question but i meant the job was being done,but it aint by me,its some1 else but a sparky has seen it and said its fine...

the 2.5mm s.w.a goes into a 30amp junction box then 2.5 T & E comes out 1 side and starts to feed sockets in a ring main 1 in and 1 out of each socket with the last cable in last socket returning to the junction box....

[buildersmate]

Sounds like you have the technical answer you sought.
Not making a big deal of it, but please understand that the only way this work can be done within the regulations is by an electrician who is registered under the Competent Person's Scheme. This is not the same thing as a registered/qualified electrician - who can be qualified but still not registered under the CPS.
If you don't comply the first time it may cause you trouble is when you try and sell the house - solicitors are very hot on checking for correct Building Regs approvals these days. Just a thought.