On 13/04/2011 17:43, Owain wrote:

I suspect that at 3 x 100A you'd use Whole Current metering unless
there's a good reason not to.

Surely it's the supplier's or metering company's decision what type of
metering to install? (Consumer chooses tariff, supplier installs
appropriate metering equipment of their choice.)

Round here (the old Eastern region) they tend to use whole-current
metering up to 3 x 200 A and CTs for larger. If you find CTs on smaller
supplies it's generally where old meter equipment hasn't been updated.

--
Andy