Apparently Canada uses 120 degree 2phase for each household as opposed to the single phase 110/220 you correctly described as being used in the US.

Canada is identical to US!
It is actually 120/240 1phase AFAIK it is also same in the US now.
https://en.wikipedia.org/wiki/Mains_electricity_by_country
Max.

 

Here is a little trivia, there is still a two phase system in Philadelphia (http://en.wikipedia.org/wiki/Two-phase_electric_power). The phases are 90° apart. John

My friend owed a commercial building in Philadelphia. I saw some of the two-phase motors that were used in it.

 

The transformer on the pole is connected to only one of the available high voltage conductors, therefore the connection to your house is single phase.

 

I know a homeowner in the middle of a residential neighborhood who was able to request and get 3-phase to his house. He was an electrician and rewired the panel to suit. He claims his house was far more efficient, but I'm not sure how unless he tore apart his larger motor-driven devices and replaced the motors. Alternatively, he may have been running "220" machines off of two of the phases, which would only supply them with 2-phase 120 at 203 volts. That would make the machines less powerful, but the bill might go down, too.

Yeah, the thread ended 4 years ago plus. I guess you could start a new thread about US Residential Power distribution. As to your friend it makes no sense? He made no mention of exactly what came in at the entry point as to voltage? Anyway, another thread would be a better way to go than resurrect this one. Maybe Mr, Bahn will be kind and close this one?

Ron

 

@haygood: Please consider the utility of reviving a thread that died a natural death nearly four years ago.

I found it useful to read the four year old thread myself, and I would assume others will, as well. Adding to it is far more efficient than starting another thread covering the same information.

 

I found it useful to read the four year old thread myself, and I would assume others will, as well. Adding to it is far more efficient than starting another thread covering the same information.

 

You guys are overthinking this question. You add all kinds of non related information like what we did back in 1946. The reality is there ARE TWO phases to residential 240volt power. It is NOT IN a SINGLE PHASE. It does not matter how many degrees apart they are. The "industry" calling it single phase power is not accurate and it confuses attempts to understand electricity at the basic level. Don't call it what it ain't.

 

You guys are overthinking this question. You add all kinds of non related information like what we did back in 1946. The reality is there ARE TWO phases to residential 240volt power. It is NOT IN a SINGLE PHASE. It does not matter how many degrees apart they are. The "industry" calling it single phase power is not accurate and it confuses attempts to understand electricity at the basic level. Don't call it what it ain't.

And that is Definately all WRONG!
Max.

 

You guys are overthinking this question. You add all kinds of non related information like what we did back in 1946. The reality is there ARE TWO phases to residential 240volt power. It is NOT IN a SINGLE PHASE. It does not matter how many degrees apart they are. The "industry" calling it single phase power is not accurate and it confuses attempts to understand electricity at the basic level. Don't call it what it ain't.

 

The reality is there ARE TWO phases to residential 240volt power. It is NOT IN a SINGLE PHASE.

Absolutely incorrect.
IT IS SINGLE PHASE.
You are the one confusing the issue with your alternate reality and calling it "what it ain't".
USA and Canadian residential power is single-phase 240V center-tapped from the transformer.
Thus you have 240V single-phase hot-to-hot, or 120V single-phase hot to neutral (the center tap).
Of course the two 120V signals appear as 180° out of phase as referenced to neutral but that does not make it "2-phase".
Look up the definition of 2-phase if you are not convinced.

 

This just in. Transformers can actually create phases. Not! Transformers can create split phase which is what my residential service is. It involves magic but does work out well and has for years. Hard to believe been 5 years on this thread as it seems like only yesterday. Least I forget my service is in Cleveland, Ohio USA.

Ron

 

The latest reviver of this topic is correct up to a point.

If someone on another planet where to take the basic concept of the three-phase system that we have and generalize it and then make a two-phase system, they would end up with something that, to the end user, would be indistinguishable from what a user here would call a split-phase system.

If someone decades ago could have looked forward far enough there is a good chance that we would also call today's split-phase system a two-phase system (and what we call a two-phase system today might be called something like a quadrature-phase system) and, as the reviver notes, this likely would make understanding some of these concepts at least a bit easier for new folks to the field. But they didn't and, as in so many things, we have to live with the terminology established and adopted long ago. That's just the way it is and no amount of wishing or pontificating is going to change it.

 

Split-phase and two-phase systems are completely different animals mathematically in operation and physically in generation.
https://en.wikipedia.org/wiki/Two-phase_electric_power

 

Split-phase and two-phase systems are completely different animals mathematically in operation and physically in generation.
https://en.wikipedia.org/wiki/Two-phase_electric_power

No one has said that these two systems (which could be called fred-phase and sue-phase systems) are not completely different animals. either mathematically either in operation or physically in generation. But there is nothing magical about the name -- they arose arbitrarily. There is NOTHING in the name "two-phase" that requires or implies two phases 90° out of phase -- this is purely a matter of historical convention. Both names are much more naturally description of what we call a split phase system; but what we call a two-phase system was developed for industrial purposes and was christened as being "two-phase" (which is a perfectly acceptable description, though arguably is just a special case of a generalized two-phase system with a particular phase offset). When what we call "split phase" arose it could easily have been called "two-phase" but that would have conflicted with an existing and widely adopted use of that term for something else, so a different name was coined.

Similarly, there is nothing that mandates that the term "three-phase" must refer to power waveforms that are 120° out of phase from the other two. That is just one special case of what is a family of three-phase systems. But if someone where to find a use for a three-phase system that did not have those phase relationships, they would almost certainly coin a different name to avoid confusion.

Things get more convoluted because some definitions of "polyphase" systems are crafted so as to try to embed some since of the historical terms into the definition, but the result is that they can be mutually contradictory. One definition attempts to exclude split-phase systems as being multi-phase systems by requiring that polyphase systems must have three or more phases that are equally spaced in phase, which would mean that a two-phase system is not a polyphase system, when most descriptions of it indicate that it is. If just the requirement of a minimum number of phases is removed, then clearly what we call split-phase would fall under this definition but two-phase would not. Others require that a polyphase system must deliver constant power to a rotating load (which two-phase systems do while split-phase systems do not) and yet others exclude split-phase systems because they do not define a unique rotation of the magnetic field.

But all of this is still human-crafted definitions to force an outcome, and not a natural meaning of the terms.

 

Your post is exactly why this thread should have been allowed to die a natural death years ago.

 

Your post is exactly why this thread should have been allowed to die a natural death years ago.

A flick of a moderator's switch could do that.

 

And every time we lock a thread because it gets resurrected, people gripe and complain about the moderators being heavy handed.

 

Here is a little trivia, there is still a two phase system in Philadelphia (http://en.wikipedia.org/wiki/Two-phase_electric_power). The phases are 90° apart. John

This was the original 2 Phase. When 3 Phase (0 / 120 / 240 ) caught on, if I recall correctly, a "Scott" connection was engineered to convert between the 2.

 

Someone tell me hos a transformer can create poly phase? Now if a transformer can create poly phase they why, going back in time, did we have motor generators like the old KATO units to create poly phase, for example run three phase motors? Why wasn't just a transformer used? A single-phase transformer (primary) with a series/parallel 120/240V secondary winding has two separate 120V secondary windings and is usually connected into a 3-wire system. This is why I can't refer to my residential power as two phase and refer to it as 240 VAC "split-phase". Transformers cannot convert a single-phase source to a three-phase source or for that matter a two phase source. That's my story and I am sticking to it. Possibly the poster who mentioned this could elaborate on why they feel the way hey do?

Ron

 

And every time we lock a thread because it gets resurrected, people gripe and complain about the moderators being heavy handed.

You get to pick the lesser of two weevils