On Wednesday, February 14, 2018 at 6:52:43 PM UTC-5, Diesel wrote:
Pat L
Wed, 14
Feb 2018 17:23:30 GMT in alt.home.repair, wrote:

I bought two mahjong machines in China to use in the US but I
forgot they use 220 over there. So I want to install a US 220V
20A female receptor by using two legs of 110V 15A circuits and
mounting a box next to one of my 110v outlets. That done I want to
convert that over to 220V, neutral, & ground to run my machines.

They do, but, it's not afaik, split like ours is. The 220volts there
is coming via a single wire. That's not how we do it, here. We take
both 120volt legs to get the 240volts on two wires, not one.

That would be some remarkable physics to supply power using only one wire.
Those Chinese must be really clever.



The cord into the machine has "L" "N" and "gnd". I want to
combine the two 110 legs to one 220 leg.

You'll be buying a suitable converter then. You can't just take our
120volt lines and 'combine' them. You'll have a very spiffy looking
arc flash if you try.

No arcs. If the two 120V circuits are on the same hot leg/phase, then
nothing will happen. If they are on opposite legs, which is what
the poster said they were going to do, then you have 240V between
them which is what the machine needs. That is assuming it's here in
the USA and it's OK with 240V instead of 220V. They could theoretically
turn two regular circuits into a shared neutral edison circuit, which
is what it sounded like they were talking about doing. There may be
code issues, but the physics is straightforward.