I imagine I could get an argument started at an IEEE meeting about what you call single phase too but it would not happen at an IAEI meeting. If you are talking about things in the NEC, the definition is well established.
You guys rock on. I am out of this
We try to stay civil among our a.h.r friends! :)
Yes. Indeed. Thank you *all* very much.
I especially loved the gfretwell pictures (they were gorgeous!). I can't wait to get an ammeter to test my currents at the pole!
I agree. Since I'm *not* an EE, and never will be, I'm *just* a homeowner, who wants to understand a bit more than I did.
And now, I do. I can recognize now things in my main breakers that I never noticed before, and, I can recognize similar things in my three subpanels.
This is all good information!
Thanks.
It's not that you asked the question, it's that you wouldn't accept the answer even after it's been explained to you by several EE's, electricians, etc. And we did give you references along the way, you just didn't even acknowledge most of them. Including the one I gave you from Wikepedia that shows how power is transmitted from a 3 phase power source to a 3 phase load, the current flows, and it can be done over just the 3 phase wires. There is no earth path there and if you looked at the animation, you can see that it's not needed.
Here's another puzzling angle. You appeared to understand the difference between a neutral and ground in your own panel after it was explained to you. Well, if using the earth as a return path for power is how power is routinely deliverd, what is that neutral doing there? Why waste money on it? The center tap of the transformer is grounded, your house neutral bar is grounded. They are only a couple hundred feet away. So, why do they have that neutral wire there if the earth is just as good?
Except of course there is no evidence that there was ever any argument. The paper was presented by an IEEE engineer with a long list of technical papers on power systems, power systems modeling, etc. It was presented at an IEEE conference on power engineering. It was published by the IEEE.
If you are talking about things in the NEC, the definition is
The definition of what? You've hurled insults, that I'm confused or know very little. All I've asked of you is to define the electrical engineering term phase. Yet, you can't do that.
I asked the question about a multiple tap transformer because I don't under stand the details about how a part of a circuit gets "out of phase."
We're using the word phase in several different ways and that's part of the confusion at least for me.
I'm not sure it makes sense to say the two lines of a 240 volt service are
180 degrees out of phase even if technically they are, because that seems t o imply a two phase supply, and that you can create an infinite number of p hases with a multiple tap transformer.In my blissful ignorance I just always considered one line to be +120 volts referenced to ground, and the other -120 volts. I'm pretty sure that's wr ong, but at least it's not confusing.
I admit I don't understand the fine details here. So, suppose I take my 12
0 volt singlephase house current, and I connect two incandescent light bulb s in series, each with a resistance of 60 ohms. Total resistance is now 12 0 ohms so I should have 1 ampere of current flowing. If I measure the volt age across both bulbs I should have 120 volts; but if I measure from betwee n the two light bulbs in either direction I will read 60 volts (and the bul bs won't be all that bright). (but I don't care, I'm not going to read by them; this is a thought experiment)NOW: are those two voltages 180 degrees out of phase? If not, why not? T his is exactly analogous to the center tapped transformer, with the sole ex ception that I didn't ground the center of the lightbulb circuit.
What if I used 4 bulbs? Etc.
erstand the details about how a part of a circuit gets "out of phase."
he confusion at least for me.
e 180 degrees out of phase even if technically they are, because that seems to imply a two phase supply, and that you can create an infinite number of phases with a multiple tap transformer.
See the new thread I just started on electrical phases. I laid out an interesting exercise in looking at phase, where I start out with what everyone here agrees is 3 phase and morph it into two phase and it's identical, indistinguishable, from split-phase 240/120V.
ts referenced to ground, and the other -120 volts. I'm pretty sure that's wrong, but at least it's not confusing.
It's not wrong. But when you have a periodic waveform and one wave is the inverse of the other, it's also referred to as an 180 deg phase difference. That one leg is 180 deg out of phase with the other. And if you look at those two waveforms on a scope, that is what you see.
Here from white papers from electrical eqpt manufacturers:
If you look at the ends of the two bulbs referenced to the mid-point, then yes. When one is +60, the other will be -60. You could hook up a scope, use the center as the reference, put one probe on the top of one bulb, the other on the bottom of the other bulb and you'd see two sine waves, 180 deg out of phase. The disagreement is that those on the other side of this refuse to call that a phase difference. They say it's just
180 deg opposite. Well, when you have two sine waves that are the opposite of each other, their phase relationship is that they are 180 deg apart. Which is why I've asked those on the other side 10 times to simply define the term phase. Yet despite telling me that I'm the one that is confused, not one of them can define it. How can you speak about something and not be able to define it?This is exactly analogous to the center tapped transformer, with the sole exception that I didn't ground the center of the lightbulb circuit.
If you use 4 bulbs in series and used the center point as a reference, you would see +30V, +60V, -30V, -60V again with the sine waves 180 deg out of phase.
Not very well. Near me, 5,000 people without power.
. Christopher A. Young Learn about Jesus
It is not two phase, it is a single phase sin wave.
AC current changes direction 120 times per second.
At any point in time (with exception of crossing 0), the electricity is either flowing
from L1 thru the neutral to L2
or
from L2 thru the neutral to L1
So, 60 cycles per second changes 120 times?
nderstand the details about how a part of a circuit gets "out of phase."
ither flowing
Tell that to the IEEE power engineers:
"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. Further, the standard 120/240 secondary is different from the two phase primary system in that the secon dary phases are separated by 180 degrees instead of three phases separated by 120 degrees. "
Or these electrical eqpt manufacturers:
I've asked 12 times now for those of you who claim you can't view split-phase as having two phases present to give your definition of "phase". It's pointless to claim anything when you can't define a simple engineering term.
Also see the other thread I started where I start out with 3 phase and morph it into 2 phases, indistinguishable fromm what you have in a 240/120V split phase service.
I think perhaps you did not read for comprehension.
I did not say it is two phase. I don't believe it is two phase. But clearly there is a phase relationship between part of the wire and another part, in that ON THE SAME WIRE some part of it is 180 degrees out of phase with another.
confusing, but yes. the key phrase is 'changes'
take a sine wave at the top goes from forward to reverse, at the bottom goes from reverse to forward, so in one cycle at 60 Hz, you've changed direction twice, or 120 times.
The better point might be to ask, "what the hell have you gained by this type of confusing model/dialogue?"
People should say what they mean, mean what they say; and get on with it. This thread has turned into a troll's paradise.
Yes, reference a 60 hz AC sin wave. It changes direction twice per cycle.
snipped-for-privacy@snyder.on.ca wrote in news: snipped-for-privacy@4ax.com:
Which obviously qualifies you to make sweeping generalities about the entire North American continent -- NOT.
And yes, I'd say that working on rural African systems *does* qualify as "limited experience". You clearly don't understand much beyond Canadian codes and practices.
I'm a church going man. Won't have sin wave in my house!
erstand the details about how a part of a circuit gets "out of phase."
he confusion at least for me.
e 180 degrees out of phase even if technically they are, because that seems to imply a two phase supply, and that you can create an infinite number of phases with a multiple tap transformer.
ts referenced to ground, and the other -120 volts. I'm pretty sure that's wrong, but at least it's not confusing.
120 volt singlephase house current, and I connect two incandescent light bu lbs in series, each with a resistance of 60 ohms. Total resistance is now 120 ohms so I should have 1 ampere of current flowing. If I measure the vo ltage across both bulbs I should have 120 volts; but if I measure from betw een the two light bulbs in either direction I will read 60 volts (and the b ulbs won't be all that bright). (but I don't care, I'm not going to read b y them; this is a thought experiment)This is exactly analogous to the center tapped transformer, with the sole exception that I didn't ground the center of the lightbulb circuit.
"In my blissful ignorance I just always considered one line to be +120 volt s referenced to ground, and the other -120 volts. I'm pretty sure that's w rong, but at least it's not confusing."
It is wrong. And while it seems like it's not confusing, it is in fact con fusing you. Because AC is neither negative nor positive, it's both. It is - half the time and + the other half.
Your home power is 120vac between one line and neutral. If you use both ho ts the peaks of the sine waves are opposite each other. So that when one i s on the positive peak the other is on the negative peak. So the voltage i s 240vac.
ROFLMAO! I'm so used to using the math function sin(Ø) that I forgot it was spelled sine.
Put the reference clip of a dual-trace oscilloscope on L1.
Put the probe for Trace A on the neutral/center tap.
Put the probe for Trace B on L2.
Here's what you'll see:
The scope will display 2 traces in phase sync with each other.
The only difference between traces will be that Trace B will be twice the amplitude of Trace A
Yah, you're right. There are a whole bunch of 2-phased trolls here.
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