On 28/01/2012 20:05, J. P. Gilliver (John) wrote:

[...] I'm curious what the word "final" means here, as it seems to be
being deliberately left in in a way that suggests it _is_
significant.

A final circuit is simply one that directly feeds 'points of
utilisation' - lights, socket-outlets, etc. A typical domestic
installation with a single consumer unit only has final circuits.

OTOH an installation in a larger building is likely to have a number of
intermediate distribution boards fed from the main intake via
*distribution circuits*. Said boards then feed final circuits or further
levels of sub-distribution (or both) . Distribution circuits which feed
separate (out)buildings from a common supply intake are known as submains.

HTH
--
Andy