On Thursday, February 15, 2018 at 2:09:41 PM UTC-5, James Wilkinson Sword wrote:
On Thu, 15 Feb 2018 01:03:22 -0000, Frank "frank wrote:

On 2/14/2018 7:42 PM, James Wilkinson Sword wrote:
On Wed, 14 Feb 2018 21:02:07 -0000, trader_4 wrote:

On Wednesday, February 14, 2018 at 2:38:30 PM UTC-5, trader_4 wrote:
On Wednesday, February 14, 2018 at 12:23:37 PM UTC-5, Pat L 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.

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

I know that there are converter that will convert 110V to 220V but
I am afraid the 15A circuits can not handle the machines. Anyone out
there really know what I can do or buy to make this happen?

First, if you are in the USA it's 240v, so let's assume the machine
is ok with that. You can't put a 20a receptacle on a 15a circuit, ie
a circuit with a 15a breaker and 14g wire. Looks like your only
option is a new 240v circuit.


Let's try again. I saw where you said you wanted to put in a 20A
receptacle.
But the machine only needs 10A. So, you could use a 240V 15A receptacle.
The rest of what you're trying to do gets more dicely. As I
understand it,
you want to take two existing branch circuits that are on separate
breakers,
15A?, and turn them into an Edison circuit/shared neutral circuit that
still powers the existing two circuits plus the added 240V 15A
receptacle.
You'd have to replace the two breakers with a single double pole 15A
breaker.
Then the physics and basic safety work, but you still have other
potential
issues:

Are 240V and 120V receptacles permitted on the same circuit? I don't
know of any code provision that says no.

You'd have to make sure there aren't any other code issues with
converting
this into a shared neutral circuit.

Being in the UK I'm not sure how this works in the US. But before those
namby pamby circuit breakers, you just had -110V, 0V, +110V. You could
take 110V from either of the 0V and 110V wires, or 220V from the two
110V wires. Do the circuit breakers think there's an earth fault if you
try to run a 220V device off two 110V wires? I thought an American
circuit was paired - i.e. the two 110V lines were linked and run off a
dual breaker which would accept a 220V device?


We also have 220 outlets. Think I only have one for clothes dryer but
at least well and electric stove are 220.

But what I'm interested in is do you ever have 220V devices connected to the same +/-110V wires as 110V devices, off the same breaker? If so, how does this breaker cope with THREE possible current flows?



I haven't seen 240V and 120V receptacles on the same circuit. I would
think mostly that's due to the fact that there is no need for it, eg
dryers, stoves are dedicated circuits. But IDK of any code provision
that prohibits it, nor is there any obvious safety issue. The breaker
deals with it by doing what breakers do, limiting the current to the
breaker rating.