Hi all,

I have a box of salvaged three phase sockets. They're pretty old and of
an all-metal construction. I'd like to mount a pair on my phase
convertor (when I've built it) but I don't have any plugs to match the
sockets. They have 3 phases, a neutral and an earth, but I don't think
they're CEE sockets. As far as I know the 3P+N+E CEE sockets have the
pins arranged in a pentagon, whereas these have four pins in a square
and the earth in the centre. There's an emblem made from an interleaved
"M" and "L" on the front, and you rotate the plug to switch on the
power. Here's a pictu

http://www.mythic-beasts.com/~cdt22/socket.jpg

Any idea what they're called? That way I might stand a better chance of
finding some matching plugs.

Best wishes,

Chris