And again no explanation to support the claim at all.
What a joke. So, if they differed by 170 degrees, or 190 degrees, what would the relationship be then? Almost opposite? You can't get it in your head that 180 deg phase difference is just one special case of a relationship of waveforms. How specifically they are generated matters not a wit. And for the record, saying they differ by 180 degrees is what one would expect from even a high school math student as opposed to the imprecise "opposite".
Here is an app note from an electical eqpt manufacturer that explains 240/120V split-phase:
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"The two legs, represented by Phase A and Phase B, are
180 degrees apart." Since they are 180 deg apart, wiring them together with their relative polarities will result in....
240V"
Notice that they acknowledge:
There are two phases, A and B. They differ by 180 deg in phase.
"A split-phase electricity distribution system is a three-wire single-phase distribution system."
Everyone working with power will call this a single-phase system.
Talking about 2 phases tends to confuse things. People working with power are not likely to talk about 2 phases in what is clearly a single phase system. I have most often heard the 2 different hots referred to as "legs".
A "phase" that is always simply the negative of the other "phase" (the same as 180 degrees out of phase) is meaningless.
Talking about phase relationships is entirely reasonable.
There is a specifically defined 2-phase system. It is not 180 degrees apart.
Sorry for runing half of the thread. A simplle RTFM and we would not have a
500 reply thread..(grin).
Guess that I should ruin the other half and say that for 2 phase power the phases are not 180 deg out of phase, but 90 deg out of phase. The split phases that most of the US has is 180 deg out if you want to call it that.
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That explains how true 2 phase power is generated.
Now can we get back to spraying some WD-40 on the dryer so the 90 deg will slide over to 180 deg on the phasing.
All this could have been avoided if people would just spray some WD-40 in the dryer to displace the water.
"The two halves are 180 degrees apart with respect to center point."
It's also split phase. When you split something, do you still only have one? Cite me an example.
Only if you don't understand the issues.
People working with
It's no more meaningless than a phase difference of 120 deg, 90 deg or any other difference. It is what it is. If you didn't have a
180 deg difference, you couldn't support 120V and 240V with those
3 wires.
And that was what started this when it was stated that the two hots on a 240V circuit have a 180 deg phase difference. It of course is true. You can hook up a scope and see it. But KRW insists that it can't be called a 180 deg phase difference, it has to be called "opposite", which makes no sense.
I agree with that. But again, the post that started all this did not call it a "2 phase system". The observation was simply made that the two hots in a 240V connection are 180 deg out of phase with each other. Actually, I think the poster made the error of saying they were 120 deg apart, but that was quickly corrected.
Good grief. Are you for real? Now you're going to claim that if we hook up two inputs of a scope to the two 240V hots, the waveforms are going to be so far different from perfect sine waves that the phase relationship can't be determined? It doesn't fall apart at all. You could have a sine wave and a sine wave with lots of noise on it. As long as they are recognizable as oscillating waveforms with the same freq, it's entirely appropriate to ask what the phase relationship is between them. And in this case the relationship is that they differ by 180 deg.
se distribution system. It is the AC equivalent of the original Edison thre e-wire direct current system. Its primary advantage is that it saves conduc tor material over a single-ended single-phase system while only requiring s ingle phase on the supply side of the distribution transformer.[1] The two halves are 180 degrees apart with respect to center point.
I see and your reference would be?
I see, and your reference would be?
Here's another reference, an app note from an electrical eqpt manufacturer, the describes split single phase:
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"The two legs, represented by Phase A and Phase B, are
180 degrees apart. "
Bingo. Exactly what Mark and I have been saying all along. Hook up a scope and see. Or dig your hole ever deeper as usual, your choice.
No, it's not meaningless. That's what it is. It's off the opposite side of the transformer so *is* a negative.
When there is a phase relationship, it is. In the case of an Edison connection there isn't, between the two legs. They're opposites. If you cut the power to the transformer, both legs will disappear together. There will not be a pi difference. If there is a line distortion, it will appear at the SAME time on both legs, but opposite WRT each other. There will not be a phase difference. Saying there is, is often slang but it just adds confusion, as you point out.
Saying that there are two phases (in an Edison circuit) confuses the issue completely. There simply aren't. There is a reason they're known as "legs", not "phases".
Right. The only useful two-phase system I've seen has them 90degrees apart.
3 phase power is in interesting thing. At the generator (I am simplifying here a bit) there is a rotor that spins and there are 3 pickup coils aroun d it spaced at 120 degrees. This is 3 phase power. If you connect this to a motor with 3 coil spaced at 120 deg the motor will spin in lock step wit h the generator IN the SAME direction. This is the kind of power used for many large industrial applications.
The power in your home is derived form ONE of these wires. The one phase goes through a where TWO copies of the same waver are crea ted, but one is the inversion of the other. Each of these two voltage are
120 V (in the US) relative to ground. And there is 240 voltages across the m. Technically both of these waves are derived from the SAME phase. One i s the inverse of the other. But it is the same signal as if it were 180 de grees apart. If you put another imaginary coil in the generator 180 deg fr om one of the other, this would create the same two signals. In reality t here is not a coil at 180 degrees so technically the power in your home is SINGLE phase and the the two voltages are inverse of each other. This is c ommonly referred to as 180 deg out of phase because it is equivalent but in reality it is not created that way. It is created by an inversion.
Back to the dryer, in the old 3 wire systems, the safety ground and the neu tral are the same wire and this was allowed by code even though it is stupi d and can be dangerous. New installations require a 4 wire connection wher e the neutral and safety ground are separate wires. If you have dryer conn ected by a 3 wire system in your house, I would suggest you add another saf ety ground wire just in case the neutral/ground develops an OPEN circuit wh ich could feed dangerous voltage onto the case of the appliance.
Of course you didn't respond. The few responses you give are typically one word, like "wrong" or some sarcastic remark that ignores the issue.
Where's your response to this, from an electrical eqpt manufacturer?
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In describing 240/120V split phase they say:
"The two legs, represented by Phase A and Phase B are
180 deg apart."
Exactly what the poster said that you claim is impossible, wrong, stupid, etc.
Or how about this. Are you familiar with the IEEE? The Institute of Electrical and Electronic Engineers? Are they a respected peer reviewed group or also just a bunch of idiots? From one of their conference papers on power systems, which was published and presented at a conference:
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4520128
"Distribution engineers have treated the standard "singlephase" distributio n transformer connection as single phase because from the primary side of t he transformer these connections are single phase and in the case of standa rd rural distribution single phase line to ground. However, with the advent of detailed circuit modeling we are beginning to see distribution modeling and analysis being accomplished past the transformer to the secondary. Whi ch now brings into focus the reality that standard 120/240 secondary system s are not single phase line to ground systems, instead they are three wire systems with two phases and one ground wires. "
It couldn't be any clearer. The author of that IEEE paper says "they are *not* really single phase systems, instead they are 3 wire system s with two phases".
Bingo! Exactly what I've said. And now you have it from an IEEE conference paper on electrical distribution systems. Read it and learn.
If you spent half as much time learning as you do with the attacks, you might have some hope.
Remember when everyone was an idiot who told you that you were wrong when you claimed it was illegal for an employer to help pay for Obamacare for their employees? Or how about the time you made an ass of yourself, with me, Bud, RBM, trying to explain to you that you didn't know what you were talking about with regard to a 4 wire vs 3 wire appliance connection? Just like those, here you are. With no references, just your arrogant, ignorant, flapping gums. Well congratulations, you've just done it again.
ase distribution system. It is the AC equivalent of the original Edison thr ee-wire direct current system. Its primary advantage is that it saves condu ctor material over a single-ended single-phase system while only requiring single phase on the supply side of the distribution transformer.[1] The two halves are 180 degrees apart with respect to center point."
Oh, I see. "opposite" is the precise term according to you. While 180 deg phase difference is slang. Go figure.
I can read and I'm sure everyone following the thread can too. They know you've once again made a complete ass of yourself. The IEEE paper proves it. But I know you'll just say that's wrong too. BTW, where are YOUR references?
I wish I actually understood what you're trying to ascertain so that I could give you the answer you seek to help you explain it to me.
What I can *see* are three huge aluminum wires going into the circuit panel at the outside wall of the house (my power wires come from underground, which is the code around here).
All three are insulated; one, the smaller-gauge wire, is striped (presumably that's the neutral which, I believe, is tied to ground somewhere a few hundred yards away, and which theoretically carries the current back to the power company to complete their power loop).
What does the insulation on all three incoming cables tell you?
Most pivot irrigation system run off 3ø 480VAC. We sometimes tap power off the supply for the grain bins. Those are typically 1ø?? 240 VAC like the supply for dryers. We add a step up transformer and a phase converter to make the pivots run. Does that alter your thinking?
I'm perfectly happy to be wrong, as long as I can figure out from the correction what the right answer is.
Hmmm... Ok. I did not realize that you're only getting *one* of the three hot wires from the distribution pole. If it helps, here is a picture of what is coming into my house from underground, from the transformer:
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I had to break a seal to open that separate panel cover, so I guess they don't want us messing around with these wires; but it seems if I had an oscilloscope, I would check the phase difference between the two thicker non-striped wires.
I checked the voltage with my flukemeter which showed they were each 120 volts ac with respect to the neutral.
But, you're saying *those* two wires are 180 degrees out of phase with each other, right?
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