Yes, words mean things. And the term "phase" is a term widely used in math, physics, engineering. In the context it's being used it only means the relationship between two waveforms that are present at the 240/120V dryer connection.
If you were in school and they hooked an oscilloscope with two inputs up to:
Dryer hot 1 and neutral Dryer hot 2 and neutral
and showed you those waveforms, only calling them waveform A and B and asked what the phase relationship was between them, what would your answer be?
Hmmm, Let's refresh trigonometry from HS, draw the AC wave form on a piece of paper(one full sine wave, 1 Hertz), what phase means or related term leading or lagging by such and such degrees. L1 leg represent top half of sine wave and L2 bottom half. So how many degrees apart between L1 and L2? For convenience we can say that L1 is positive half and L2 is negative half or vice versa..
Re-read what I wrote, and what you and others are trying to assert. Think really hard about it. The secondary of a residential transformer only has "one" winding. It is fluxed by "one" winding. Meaning that it is not a poly-phase system Hence, no phase shift. How the primary winding is powered varies, and just might use two phases of a three phase system, yet since there is only one secondary winding, the secondary winding only has one phase angle. Zero offset between the hot legs and the center tap for there is only one winding and either side of the center tap is at the same phase angle as the other.
To kill two birds with one stone.
In the utility world, the term "phase" references one leg (output) of a poly-phase system. This does not matter if the transformer is delta or wye. I would say the same thing about generators, but you would be hard pressed to find a three-phase delta generator. (trying to get a ground reference is a pain in the ass and cost a a lot more money). The three outputs are called A, B, and C. There is more about delta systems, but that does not pertain to this conversation.
Around here, Arkansas, they supply the primary with one hot and a neutral. In the Bay Area, Ca, the primary uses two hots. Not necessarily poly-phase in origin, but the closer you are to commercial buildings, and such, the greater the chance that this is the case.
Regardless, a three phase wye generator and/or transformer is the only true power source on the grid that has a "neutral". Something you will not see around your meter-main, ever (unless you are very lucky :-)).
I could go on, but another football game started...
I agree. They are hung up on the fact that in an electrical power distribution system, it isn't referred to as two phase. But it is called "split phase", and when you split something, well it seems you wind up with more than just one.
I would not call the electrical service two phase, as I think someone here might have, but in fact you do have two AC waveforms present that are 180 deg out of phase with each other.
You could make the more general case of a "box" that you put a sine wave into and get various sine waves out of. They can each be described in terms of their frequency, amplitude, and phase relationships to the original and each other. You could have one, two, three,
10 different phases, all derived from one input. Are they going to say that if one of them is 180 deg out of phase with the input, that it's not correct to say that? You can only call it the "opposite"? Good grief!
Hi, I think simply white always carry current. green is safety in case some thing happens to white wire(connection) Every thing we touch should be at ground level all the time.
I have thought hard about it and I'm fully aware of the meaning of the term phase.
The secondary of a
Hook up a dual input oscilloscope to hot 1 and neutral and hot 2 and neutral at the dryer. Show that plot to a school student and ask:
"What is the phase relationship between waveform A and B?"
What's your answer?
How the primary winding is powered
Each side of the secondary is 180 deg opposite the other. It is referred to as "split-phase", right? When you split a something, do you still have just one?
Here:
Split-phase electric power
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"A split-phase electricity distribution system is a three-wire single-phase distribution system. It is the AC equivalent of the original Edison three- wire direct current system. Its primary advantage is that it saves conducto r material over a single-ended single-phase system while only requiring sin gle phase on the supply side of the distribution transformer.[1] The two ha lves are 180 degrees apart with respect to center point. "
Note the very important last sentence. That is all I and Mark Loyd and others are saying.
Yes, but the utility world doesn't own the term phase. It's widely used to describe the relationship between two or more waveforms in math, physics, electrical engineering. And in the broadest sense, in any of those fields, it's simply the relationship between two or more waveforms. Exactly how they got generated doesn't matter. If you can hook up a scope and see two different waveforms and one is 180 deg out of phase with the other, then that is the relationship, is it not? And two sine waves differing by 180 degrees is what you get from a center tap transformer delivering 240/120.
Hi, Of course in radio wave dealing with E and M field, in acoustics dealing with sound wave, in hydraulics dealing with liquids, gases, etc. Doppler effect in radio wave or sound wave, light wave, etc., etc. Also not all waves are sine waves.
So typical. Instead of writing a few sentences to try to explain your case, you start with the insults. That's because you have no case.
How is a sine wave, which of course is exactly what AC power is, a "degenerate case"? And they don't look the same, they have a "phase" relationship, expressed in degrees to each other.
Yes, because you refuse to look at anything that shows you're wrong.
Is wikipedia lying too:
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A split-phase electricity distribution system is a three-wire single-phase distribution system. It is the AC equivalent of the original Edison three-w ire direct current system. Its primary advantage is that it saves conductor material over a single-ended single-phase system while only requiring sing le phase on the supply side of the distribution transformer.[1] The two hal ves are 180 degrees apart with respect to center point.
Read the last sentence. They are saying exactly what I, Mark Loyd and at least one other person have been telling you. And that is that the two hots at the dryer are 180 deg out of phase with each other.
But that isn't what you objected to. You objected to someone saying the two hot legs at the dryer are out of phase by 180 deg with each other. That is true as can be seen on a scope. And when you split something, can you cite an example where after splitting, you still have just one?
It is common practice to use the same bus for both neutral and ground in a service panel. The bus is bonded to the enclosure (N-G bond), and the earthing electrode system connects to it.
Can also be done with a separate ground bar connected to the enclosure. (Neutrals can't connect to such a ground bar.)
The neutral bar in a service panel must be bonded to the enclosure/ground system.
Not obvious what you are saying.
The system N-G bond is at the service disconnect.
It is common for the neutral in a meter can to be connected to the can. That is done to "ground" the can.
Your post would be more clearer to most people if you used "neutral" instead of "grounded conductor".
Because a single frequency sine wave is symmetrical, both forward and backward, and top to bottom. Add some distortion (which is always present in the real world) or delay and your gross simplification falls apart. Inverting and phase shifting are entirely different things.
You're some piece of work, Trader. You can't admit that you're wrong
*IN ANYTHING*. Even though you claim to be an EE, you're wrong. Get a refund. Invest in Cracker Jax. It's better than your degree.
What do you want to ruin half the thread for? RTFM? I agree the dryer appears to be wired right for a 3-wire connection. My guess is the white wire that connects to the frame at the left connects internally to the neutral, and bonds the neutral to the frame.
Typical. Don't respond to the specific points that go to the issue, just start with the usual insults. A sure sign that you've lost the argument and can't address the points.
Here are some references for you that say exactly what I and Mark Loyd are saying:
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"A split-phase electricity distribution system is a three-wire single-phase distribution system. It is the AC equivalent of the original Edison three- wire direct current system. Its primary advantage is that it saves conducto r material over a single-ended single-phase system while only requiring sin gle phase on the supply side of the distribution transformer.[1] The two ha lves are 180 degrees apart with respect to center point."
Note the last sentence.
Or this app note on power configurations, which shows and talks in detail about split-phase:
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Second diagram down:
"The two legs, represented by Phase A and Phase B are 180 degrees apart. Since they are 180 degrees apart, wiring them together with their relative polarities will result in...."
THAT is exactly what you objected too. A poster made reference to the fact that the two hots of a 240V service differ by 180 degrees in phase. You claimed that they are not 180 deg different in phase, just "opposites". Which is like saying the south pole doesn't differ by 180 deg from the north pole, it's just the "opposite". Any one with any math, science background knows you're wrong here.
Remember how you made a complete ass of yourself not knowing how a 4 wire vs 3 wire oven connection worked? Even as two EE's and an electrician told you that you were wrong. Even as I said just go look at any electric stove installation manual, which you refused to do? Well, here you are again.
Are you as sure of that as were about it being illegal for an employer to help pay for employees to buy Obamacare policies on the exchanges? Then too, you started with the insults, the one word non-answers, and of course you were totally wrong.
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