You’re correct, phase-to-phase is 173.2% of the phase-to-neutral voltage in 3-phase “Wye” service.
But that’s not what consumers (typically) use in North America. We don’t bring three phase to the home.
Our single-phase final distribution transformers have a center tap on the secondary coil, bonded to neutral. So, one side of the coil provides a 120v leg with respect to that neutral, and the other side provides an opposing leg, 180° from the first, and 120v with respect to that same neutral. Most of our appliances use leg-to-neutral, 120v. But leg-to-leg is 240v.
(Commercial and industrial facilities can get a wide variety of voltages in single or three phase, and we do have some actual, 2-phase generators and customers: the phases are 90° apart rather than 120° or 180°)
The technology connections video talking about 240v power mentioned some apartment buildings having 208v because they’re bringing in two phases instead of center tapping or whatever. So their comment could be right in the correct locations i think.
And lots of things meant to run on 240 are dual labeled 208/240. If it’s a motor it will end up running a little hotter, if it’s a heater it will end up a little colder.
Like others said, we do split phase to residential in the US. So the funny thing is, for all of our wimpy 120V outlets, our homes literally have 240V service. We just don’t wire it to the outlets because you know, standards and fire.
I just made dinner on my induction stove that’s connected to 240V and it’s wonderfully powerful. We use special outlets for 240V, and it’s typically for the major appliances you might expect, if they are electric versions. Oven/stove, clothes dryer, water heater, heat pump, air conditioner, EV charger, etc.
Two-Phase has two legs, 90 degrees apart. When one phase is at maximum amplitude the other phase will be at zero.
Split Phase is 180 degrees apart. When one leg is at maximum positive amplitude, the other will be at maximum negative amplitude. When either is crossing zero, the other is also crossing zero, in the opposite direction.
But it wouldn’t be 200%, it would be something like 170% power assuming 3 phases, right. Too lazy to do the math.
You’re correct, phase-to-phase is 173.2% of the phase-to-neutral voltage in 3-phase “Wye” service.
But that’s not what consumers (typically) use in North America. We don’t bring three phase to the home.
Our single-phase final distribution transformers have a center tap on the secondary coil, bonded to neutral. So, one side of the coil provides a 120v leg with respect to that neutral, and the other side provides an opposing leg, 180° from the first, and 120v with respect to that same neutral. Most of our appliances use leg-to-neutral, 120v. But leg-to-leg is 240v.
(Commercial and industrial facilities can get a wide variety of voltages in single or three phase, and we do have some actual, 2-phase generators and customers: the phases are 90° apart rather than 120° or 180°)
The technology connections video talking about 240v power mentioned some apartment buildings having 208v because they’re bringing in two phases instead of center tapping or whatever. So their comment could be right in the correct locations i think.
I’m clearly no sparky.
Correct. It’s not typical, but it does exist. 208v is usually close enough for 240v appliances.
And lots of things meant to run on 240 are dual labeled 208/240. If it’s a motor it will end up running a little hotter, if it’s a heater it will end up a little colder.
Like others said, we do split phase to residential in the US. So the funny thing is, for all of our wimpy 120V outlets, our homes literally have 240V service. We just don’t wire it to the outlets because you know, standards and fire.
I just made dinner on my induction stove that’s connected to 240V and it’s wonderfully powerful. We use special outlets for 240V, and it’s typically for the major appliances you might expect, if they are electric versions. Oven/stove, clothes dryer, water heater, heat pump, air conditioner, EV charger, etc.
US has two phase power in residential households
Split phase, not two phase.
Two-Phase has two legs, 90 degrees apart. When one phase is at maximum amplitude the other phase will be at zero.
Split Phase is 180 degrees apart. When one leg is at maximum positive amplitude, the other will be at maximum negative amplitude. When either is crossing zero, the other is also crossing zero, in the opposite direction.
They are referring to recombining the two halves of split-phase like what is done with an outlet for an electric dryer or oven, but outside the walls.
https://theengineeringmindset.com/120-240v-split-phase-us-can/