On Thu, 6 Jun 2019 19:51:22 +0100, Nightjar wrote:

The USA has a +55v 0v -55v system.

You sure about that? I thought US domestic supplies where 110 V
biphase. ie 110 - 0 - 110. Normal appliances where connected between
0 and one of the phases. Big loads like washers connected between the
phases and ran off 220 V and thus half the current for the same power
@ 110 V.

--
Cheers
Dave.