On 17 May 2004 06:49:23 -0700, in uk.d-i-y
(jacob) strung together this:

What size flex 3 metres long for a 2.2kw 3 phase combi woodwork
machine?

1.5mm2.

What size cable to workshop (about 6 metres) to supply say max at one
time 6kw 3 phase machines?

6 or 10mm2, 32A supply as a minimum.

Would this need to be armoured or just conduited or what?

Yep, any of those.

Separate single phase elsewhere, but could I run a spur from a 3phase
wall socket to a single phase socket (same phase as other single
phase?) or is this against the rules?

Nope, you need to run the three phase submain to a 3 phase
distribution board and run you 3 phase and single phase circuits from
there.

I've got some sheathed and armoured 3 core cable. Does this need a
separate earth for 3 phase use, or do you earth the sheathing, or
both, or neither?

Both, but if you want to run single phase through it as well you'll
need a 4th core for the neutral. Some three phase machines will also
need a neutral.
--

SJW
A.C.S. Ltd.