| firstname.lastname@example.org wrote:
|> | phases are 360/2 degrees apart. 3 phase 360/3 degrees apart, 4 phase
|> | 360/4 etc.
|> That would be the normal way of thinking of it. It gets interesting when the
|> number of phases is any even number. For example 6 phase. I have mentioned
|> the concept of 6 phase before and some people get confused. If a 6 phase
|> system with phases labeled A,B,C,D,E,F (going around the circle) with phase
|> angles of 360/6 degrees each, gives you 240 volts between A and D, then why
|> can't a subsystem tapped from just A and D alone be called 2 phase? They are
|> counted as 2 phases.
| That depends on how you look at it- if you bring out only the two
| terminals A,D you have a single voltage between them. It is then
| indistinguishable from a single phase 2 wire supply. With a single
| voltage, phase, as a relative term, becomes a problem. as what do you
| relate this single voltage to?
If you have a neutral or ground or some kind of ground reference, even if
high impedance, then you have 3 points, 2 or 3 vectors, and can determine
an angle. If you don't, all you have is the voltage difference.
| If the 6 phase system is a Y rather than a polygon (super delta) then
| you have a neutral and then you can consider that you have a 2 phase
| system where the voltages Van and Vbn are 180 degrees apart. You then
| have 3 terminals. This is indistinguishable from the center tapped
| single phase system which fits what the Europeans refer to as 2 phase.
| Neither are distinguishable from a 2 wire single phase system if you
| ignore the neutral.
Is it standard in Europe to use "2 phase" to refer to what Americans mostly
use some variation of "Edison style split single phase"?
I don't like to call any AC system based on Edison in any way. Edison did
not design around AC. He did DC. Thus he didn't split his power system in
any way considering angles, because there were no angles. Edison would not
recognize the power system coming into my home. Tesla might.
And Edison is quite far from being my favorite inventor/scientist/engineer.
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