On Sun, 05 Jul 2015 09:43:09 -0700, Tricky Dicky wrote:

My Son in law wants to use powerline alongside wifi. He has a split
supply CU with separate upstairs and downstairs ring mains, will this
cause connection problems? At the last house we used powerline and also
had seperate upstairs and downstairs ring mains and found problems
unless we had the powerline adaptor son the same ring main.

I've got (TP-Link) powerline here, not just across rings, but with one
end on a separate consumer unit daisychained off the main one. Works just
fine.