Date   : Sun, 06 Sep 2009 20:19:16 +0100
From   : philb@... (Phil Blundell)
Subject: Leccy @ Acorn World '09

On Sun, 2009-09-06 at 19:30 +0100, Jonathan Graham Harston wrote:
> Also, with rings you can have as
> many outlets as you want, with a radial you may only have a maximum
> of three outlets. 

Where do you get that from?  I don't think anything in the regulations
imposes such a limit (and indeed the example radial circuit shown in
Appendix 15 depicts twelve outlets).  There's a note that "as a rule of
thumb, the floor area served has been limited to 50m^2", but even this
is not mandatory so long as the expected load is within the circuit's
capacity.

Incidentally, appendix 15 also shows a 20A protective device for a
circuit wired in 2.5mm.  I don't have an up-to-date copy of the OSG here
to look at, but it seems a bit odd that it would require only a 16A
breaker for the same circuit.

The IET also have some discussion of the relative merits and evils of
ring circuits on their website, see:

http://www.theiet.org/publishing/wiring-regulations/ringcir.cfm

p.