3 Phase 415v is also available in the UK but is normally only installed in factories for large industrial machines etc. Because the domestic supply is double the US voltage in the first place there is no need to have this sort of arrangements for anything you would have in the home.

Speaking of unusual voltages, the London Underground, like many underground/subway systems worldwide, runs on 600 volts DC. However whereas all other systems supply this at +600v through the power rail just outside the running tracks, returning through the running tracks at zero potential, in London there is a separate fully insulated negative in the centre of the tracks (those of you into these things may have noticed there are 4 rails rather than the usual 3 in London). Furthermore the 600 volt supply is at +400v in the outer power rail and -200v in the centre rail. There are a number of technical reasons for this unique method, starting with some unusual electrolysis corrosion problems the Underground is liable to in various places.

I think our poor Original Poster, who just wanted to run their television, might be getting a little lost by now !