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Help running this 220v machine in my house

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james_s:
No, it's not, when it's 180 degrees of separation it cannot create a rotating field and it's considered a single phase, calling it whatever you want creates confusion. Talk to any electrician and they'll tell you it's single phase. 2 phase power distribution did exist at one point, but it was replaced by 3 phase which can carry more power over the same wires.

https://ctlsys.com/support/two-phase_electrical_service/

"Residential electric service in the United States (120/240 Vac) is sometimes called two-phase service but this is NOT correct. It is only single-phase, since both line voltages are derived from a single phase of a distribution transformer with a center tapped neutral and are 180° out of phase with each other."

https://electronics.stackexchange.com/questions/611732/why-is-north-american-residential-power-called-single-phase


DavidKo:
There was a lot of talking about 220V vs. 230V during the switching period from 220V -> 230V and it was said that it should be not an issue since the devices were made for 220V +-10%. I do not want to say that this is a common praxis nowadays, but as rule of thumb it can be taken since the voltage in the network changes during the day and week day (cooking on Sundays vs. nights in working days) and usually some compromises on power lines are done.

IanB:

--- Quote from: james_s on January 11, 2023, 04:18:41 am ---"Residential electric service in the United States (120/240 Vac) is sometimes called two-phase service but this is NOT correct. It is only single-phase, since both line voltages are derived from a single phase of a distribution transformer with a center tapped neutral and [the two voltages] are 180° out of phase with each other."

https://electronics.stackexchange.com/questions/611732/why-is-north-american-residential-power-called-single-phase

--- End quote ---

If you divide the unit circle into thirds, you get three vectors 120° apart, giving three phases (and three phasors).

If you divide the unit circle into halves, you get two vectors 180° apart, giving two phases (and two phasors).

For electricians and power engineers it is a split phase supply, but for physicists and mathematicians there are two phases 180° apart. Trying to pretend this is not true is like trying to re-define pi as being equal to 3.

james_s:

--- Quote from: IanB on January 11, 2023, 05:31:23 am ---
--- Quote from: james_s on January 11, 2023, 04:18:41 am ---"Residential electric service in the United States (120/240 Vac) is sometimes called two-phase service but this is NOT correct. It is only single-phase, since both line voltages are derived from a single phase of a distribution transformer with a center tapped neutral and [the two voltages] are 180° out of phase with each other."

https://electronics.stackexchange.com/questions/611732/why-is-north-american-residential-power-called-single-phase

--- End quote ---

If you divide the unit circle into thirds, you get three vectors 120° apart, giving three phases (and three phasors).

If you divide the unit circle into halves, you get two vectors 180° apart, giving two phases (and two phasors).

For electricians and power engineers it is a split phase supply, but for physicists and mathematicians there are two phases 180° apart. Trying to pretend this is not true is like trying to re-define pi as being equal to 3.

--- End quote ---

I'm not saying that isn't true, I'm saying it's called single phase power. Physicists and mathematicians aren't really relevant to this particular discussion. The topic isn't mathematical theory, it's practical application. In practical application, the correct name is single phase, the panel will say single phase, the distribution transformers will be labeled single phase, in this context 2 phase means something different.

Nusa:

--- Quote from: james_s on January 11, 2023, 03:00:57 am ---
As far as I know you're still allowed to have 240V outlets without neutral. The change to the code mandates a neutral if you have any 120V loads on it. For example electric ranges used to typically use ground as neutral for the oven light and the clock and such, clothes dryers did the same with the interior light and timer. Modern dryers and ranges need a 4 prong plug and ground is used ONLY as a safety feature.

--- End quote ---

Existing installs are grandfathered (3-pin dryer plugs are common in older houses), but haven't been legal for new installs since the mid-90's.

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