Garage supply

I'd not get too hung up on that, indeed it is also possible to have a  spur from a ring that is actually a 16A RCBO, and achieve a circuit performance that is better protected than the ‘standard’  13A fused spur with a real fuse, but the RCBO is not in the back of the OSG as a standard configuration either…

Far more important is to convince yourself that the load distribution will be OK, if you like to assume  that the same piece  of wire can be both final cct for the sockets on the house ring, and in the same breath also a distribution cct for anything downstream of any fuse or circuit breaker fed by that ring, that is fine, but  it does not suddenly absolve you from combining the currents of the two functions when thinking about cable heating, and thinking about total voltage drop to the far ends including losses in all stages.

Arguably ‘the full circuit’ supplying load X ought to include the substation secondary where the electrons are excited, street mains, house fuse etc as well. If it helps pretend  you could tag one electron and follow it right round the loop, anything else is not actually a compete loop, so non-circuital. 

The last leg to the load  is only a final sub-circuit, and the rest are mid sub-circuits.. No-one bothers with that level of detail, it rapidly becomes pedantry for the sake of it.

Mike.

I'd not get too hung up on that, indeed it is also possible to have a  spur from a ring that is actually a 16A RCBO, and achieve a circuit performance that is better protected than the ‘standard’  13A fused spur with a real fuse, but the RCBO is not in the back of the OSG as a standard configuration either…

Far more important is to convince yourself that the load distribution will be OK, if you like to assume  that the same piece  of wire can be both final cct for the sockets on the house ring, and in the same breath also a distribution cct for anything downstream of any fuse or circuit breaker fed by that ring, that is fine, but  it does not suddenly absolve you from combining the currents of the two functions when thinking about cable heating, and thinking about total voltage drop to the far ends including losses in all stages.

Arguably ‘the full circuit’ supplying load X ought to include the substation secondary where the electrons are excited, street mains, house fuse etc as well. If it helps pretend  you could tag one electron and follow it right round the loop, anything else is not actually a compete loop, so non-circuital. 

The last leg to the load  is only a final sub-circuit, and the rest are mid sub-circuits.. No-one bothers with that level of detail, it rapidly becomes pedantry for the sake of it.

Mike.