John Rumm wrote:

However - more info from Toby suggests that the genset will be
configured to supply a TN-C-S style supply.

That's not allowed - using any combined neutral and earth (CNE)
conductor in a consumer's installation is illegal in the UK, under the
ESQC regulations [1].

Configure the generator to make a TN-S system. Here's a blast from the
past which includes an ASCII wiring diagram:

http://groups.google.co.uk/group/uk....n&dmode=source

I would very strongly discourage the 4-core SWA approach here, because
its unconventional nature could be quite dangerous for the unwary.
Using two 2-core SWAs will bolster up the armour CSA nicely too.


[1] http://www.opsi.gov.uk/si/si2002/20022665.htm#8 - regulation 8(4)

--
Andy