240v debate....

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Besoeker said:
Then how about you give your expert opinion on exactly why the two pulses in the SCR circuit I posted have to be 180 deg apart?
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Do you think asking it 12 or 13 times will make it any less of a stupid question? It is no different than your rectifier circuit. One SCR is operating on the positive half-cycle and the other is operating on the negative half-cycle. It is not magic and has nothing to do with a phase shift. Each diode or each SCR is forward/reversed biased every half-cycle. The half-cycles are 180? apart, so of course you have to fire the SCR's at 180?. You would have to do the same thing if they were connected to a single-winding too. Either you are being deliberately deceptive or incredibly...... :dunce:

Put your diodes or SCR's into the circuit I drew in post #417, and then tell me how the 180? phase shift is mandatory. That circuit has no phase shift, but it will do the same thing with your SCR's.

Yes, it hasn't slipped my observation that for the past dozen or so postings, you have suddenly become more rigid with your use of the Vbn and Van designations. However, earlier on, you were not only sloppy with this, but actually made statements that disregarded this. If you are changing your tune, then say so now. Your previous responses indicated that this 180? was absolute and was not predicated on a reference point. If you are changing that tune, then I/we need to know.

Besoeker said:
And why the circuits I have posted are, as you have claimed, wrong?
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Because you labeled your nodes 120V, 0V, 120V. I've said this several times, but you didn't respond except to repeat your question from above. You're so locked in your ways and want the rest of the world to follow your ways, that you no longer see the freshman error you make in your diagrams. When you label your nodes, the voltage between those nodes is derived from those labels. You therefore have zero volts from A to B. I have brought this up several times. Has it slipped your purview that no one has rushed to your defense on this matter?
 
hurk27 said:
Not sure what you mean by relative, but I wouldn't use that when paralleling the two windings of the secondary of a transformer, putting X1 with X4 and X2 with X3 might get some unwanted results.:blink:
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The relative relationships would not make those results unexpected. Polarity vs direction. Learn it. I promise you will be better for it.

hurk27 said:
If you agree with what this site had to say then you would also agree with this point they made almost at the bottom of that page I posted:
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That is a separate discussion. Sorry you can't see that. I have already said that the voltages in the same direction are in phase.
 
mivey said:
You said they were not two sources. A single voltage source has two terminals. By definition, a voltage is taken between two points.
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Besoeker said:
Not at all. the supply Jim D refers to has two hots and a common neutral.
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Besoeker said:
Should have read:
The 120-0-120 is two hots and one common neutral with Van and Vbn both 120V and mutually displaced by 180degE.
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A center tap 120/240 transformer has two 100 watt light bulbs wired to it. One on half and the other on the other half. How much current is on the neutral? Where does the current flow? Could this take place if they were 180 degrees out of phase with each other?
 
Rick Christopherson said:
Umm, here's a twist for you. Why do you think you need a common reference point in the first place? ... Voltages are determined between nodes regardless of a common point.
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But any time you want to compare to voltages, you MUST have a common reference. You should know that.

jumper said:
This is a real question. I am confused by this statement.
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You're not.

jumper said:
How can I measure a voltage without a reference point?
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You can measure it and get the voltage of one terminal relative to the next, but you will have to have the measurement to a common point to compare the two original measurements.

Rick Christopherson said:
I didn't say without a reference point. I said without a common reference point. Standard KVL sums the voltages around a loop from node-to-node. When you perform KVL based on a common reference point, then you should be referencing all of your nodes back to that common reference point for their voltage. This gets very complicated and tedious. It still works and is still true, but the equations get needlessly complicated.
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To compare any two of those, you will need a measurement to a common point. By summing in order, you build a reference chain. That is why the law works because if you make a loop, you will get back to to beginning and have closure at the original reference point.
 
Rick Christopherson said:
And I would really like to thank you for your contributions to this discussion. If it wasn't for your added brain power, this discussion might have carried on for 500 or even 600 postings.
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Rick, what has my brain power of any level have to do with your ability to answer a question?

How do your attempts to belittle those around you help you prove your point in this thread?
 
jwelectric said:
A center tap 120/240 transformer has two 100 watt light bulbs wired to it. One on half and the other on the other half. How much current is on the neutral? Where does the current flow? Could this take place if they were 180 degrees out of phase with each other?
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I told you if you did not understand post #98 and #290 you would not be able to follow along. I will simply refer you back to those instead of repeating it all over.
 
jwelectric said:
A center tap 120/240 transformer has two 100 watt light bulbs wired to it. One on half and the other on the other half. How much current is on the neutral?
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Zero of course.


Where does the current flow?
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On the two ungrounded conductors.

Could this take place if they were 180 degrees out of phase with each other?
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Could it? most certainly.

Being 180 out phase with each other is is the only way it could take place.
 
Rick Christopherson said:
Is that what your insurance company would say as they were completing the claim on your lab explosion? :lol:
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I'm sure I would get my story straight before they got there.:D

Rick Christopherson said:
Umm, you're the one suggesting the laws are flexible......I'm the one being very sarcastic about it. :D
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My post was tongue-in-cheek. :D

We both know the laws are not flexible and I am not suggesting they are.
 
iwire said:
How do your attempts to belittle those around you help you prove your point in this thread?
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I made that same observation many posts back. To me, it only hurts his credibility.

You and I have delt with a lot of people over the years and you & I both know what most professionals think about people who act like that. It never brings them value except in their own eyes or in the eyes of the like-minded.
 
weressl said:
Isn't connecting something in phase order ABC and BAC is simply CHANGING one's chosen 'reference' point? Will it produce different results in a 3 phase motor rotation?
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Rick Christopherson said:
That's not a change in reference. That's a change in the physical circuit.
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Changing bolted motor connections is no different than changing where you hold the probes of your meter.

The motor is a load, the meter is a load.

Even a layman can plainly see that. :lol:
 
Rick Christopherson said:
NO!
You do not need a COMMON reference. You need two reference points for each voltage. You know better than this!!! :dunce::dunce::dunce:
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Good gracious Rick. Re-think what you just said as I think you got caught up in the moment.

You can measure the potential of node #1 relative to node #2. You can also measure the potential of node #536 relative to node #137. But you will never be able to discern the relationship between V_1_2 and V_536_137 until you establish a common reference. Come on now, that is basic electricity.
 
iwire said:
How do your attempts to belittle those around you help you prove your point in this thread?
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And your posting to me wasn't an attempt to belittle and I didn't simply throw it back in your face? Look at your contributions to this thread before you answer that.

Don't step in front of a moving truck if you don't wish to get run over. Don't throw a stone if you don't expect a rock to be thrown back. Don't run with the big horses if you can't p**** on the tall timbers.

You knowingly enter into a discussion that you admit is over your head, and when you mock me, you complain that I return with condescension? If you asked me to hand you a 1/2" wrench and I gave you a screwdriver, you don't think you would respond in a similar tone?
 
mivey said:
Good gracious Rick. Re-think what you just said as I think you got caught up in the moment.

You can measure the potential of node #1 relative to node #2. You can also measure the potential of node #536 relative to node #137. But you will never be able to discern the relationship between V_1_2 and V_536_137 until you establish a common reference. Come on now, that is basic electricity.
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You "can", but you are the one that said you "MUST" (your emphasis). Now you're backpedling and it is a "can" not a "must"?
 
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