On Wed, 22 Aug 2007 13:49:46 -0700, mused:

i am currently installing some wiring and cannot find any reference to
trunking recommendations.

i would like to understand size versus number of cables capacity

trying to fit the following in a trunking run

3cables 2 twin+earth 2.5mm
+ 1 twin+earth 1.5mm

You could get that in a 25x16 if you wanted, just, depending on the
make. Best make it 16x40 just to be sure.

and

5cables 1 triple+earth 1.5mm
+ 4 twin+earth 1.5mm

Should get that in a 16x40 again.

what minimium size will be sufficient for each run

The above assumes that sticking the cables in trunking isn't going to
massively derate them.
--
Regards,
Stuart.