On Tue, 11 Dec 2007 23:33:57 -0800 (PST), ac1951
wrote:

...
...
... . The cable will be 2.5mm size so use this size cable for
... the spur .
... Stuart
...
... As a general rule yes but it may be larger.
...
... .

The circuit cable is larger. It has 3 coiled earth wires for a start.
I spurred off with a 30amp junction box using 2.5mm.
Why should the cable all be the same size?

Mike P