30A wiring advice

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I read in sci.engr.electrical.compliance that No Spam

I agree; that's why I don't understand the violent reaction of some US people on the subject.

No, that's specious. With one winding, you have the choice of 0 or 180 degrees phase. There is no way to get 120 or 72 degrees.

Well, that's yet another way of looking at it, better than appealing to a sum of angles being 360 degrees. My point is that a 2-phase 90 degree system is unsymmetrical, unlike a two-phase 180 degree system or a 3-phase 120 degree system. A three-phase 60 degree system would also be unsymmetrical. Unsymmetrical systems of this type can be made symmetrical by doubling the number of phases, **and this can be done by means of 1:1 transformers**. This last point applies to a single-phase supply as well, with conclusions that should now be obvious.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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Au contraire. A 90 degree 2 phase system is symmetrical. The whole thing transmits constant power (remember: sin(x)^2+cos(x)^2=1, and cos(x)=sin(x+90) A center tapped transformer doesn't transmit constant power, and its power is identical to a single phase non-center tapped transformer. A 3 phase system (with all phases available and used) is also symmetric.
--
-Mike

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No Spam wrote:

Abraham Lincoln once asked, "If you call a dog's tail a leg, how many legs does a dog have?". His answer; "Four; calling a tail a leg doesn't make it one." Particularly in a technical field, getting the terminology wrong has caused more errors than any other single factor in my experience. As I said in a previous post, this issue is defined in the same way in various standards and in every electrical engineering text I've ever seen, and the definition is as I have explained it before. Do I have the right to call a capacitor a transformer? NO!
Every hot conductor in a power system is not a "phase".

73, JohnW
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I read in sci.engr.electrical.compliance that John Wilson

You cited one ANSI standard.
I do not wish to continue this futile exchange. You are not prepared to see any other point of view than your own.
--
Regards, John Woodgate, OOO - Own Opinions Only. http://www.jmwa.demon.co.uk
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John Woodgate wrote:

I cited one ANSI standard, because it's the one I remember offhand. I have access to many others at work; this entire exchange has taken place on a weekend. If you want more references, I can supply them.
Anybody have access to a collection of IEC standards, to see what the European definition is?
In any case, most terms, including many others that are frequently misused, such as "metalclad switchgear", "circuit breaker", and so forth, are each defined in a particular standard.
73, JohnW
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Good answer. Accurate and to the point.
Unfortunately it won't change the minds of the fanatics; but you have the satisfaction of having answered the question for the rationale ones.
HR.
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On Wed, 1 Oct 2003 06:31:14 -0700, the renowned "s"

Not really. Many of us claim that two linearly dependent voltages don't represent two distinct "phases", even if one of the proportionalities happens to be -1. John disagrees.
A two phase supply with conventional 90 (or anything != n * 180, n is an integer) difference between the phases could be used in motors, as your comments suggest, or converted by a Scott-T transformer to make three-phase (or other polyphase) power. Canadian/US residential power cannot, so those who want to bring an industrial machine tool into their basement or garage have to use a static, rotary or VFD phase converter.
This has been discussed before...
Best regards, Spehro Pefhany
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snipped-for-privacy@interlog.com Info for manufacturers: http://www.trexon.com
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<...snipped...>

That is just so wrong.
--

Larry Wasserman Baltimore, Maryland
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(Lawrence Wasserman) wrote:

-- Regards, Doug Miller (alphageek-at-milmac-dot-com)
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It MUST be two phase between the two hot wires, because if it was in one (the same) phase then the heating element would not heat up.
- +ve 120V - - - - - - - - - -ve 120V
+
- +ve 120V - - - - - - - - - -ve 120V
= no potential difference between the two hot wires and so no current flow. Waves are in a single common phase.
- +ve 120V - - - - - - - - - - - - -ve 120V
+
- +ve 120V - - - - - - - - - - - - - - -ve 120V
= 180 deg phase shift, 240V potential difference at peaks therefore current flows therefore heater heats up.

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In terms of maths/physics/engineering you are clearly correct.
In terms of the US electricity supply industry, "2-phase" is a specific jargon term which applies to only one 2-phase system. In the UK electricity supply industry, the common US scheme was called 2-phase (but is long obsolete and was never common).
--
Andrew Gabriel

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Joe 90 wrote:

Lets go to the understanding of how it heats up and avoid the controversy that surrounds what you label it. Consider: + - + - A--Battery1--B--Battery2--C Let each battery provide 120 volts. A to B = 120v; B to C = 120v; A to C = 240v or in other words, a simple series circuit (the circuit being completed by the voltmeter). Either battery can be used independently of the other, providing 120v DC, or they can be used in series to provide 240v DC.
Now, substitute the secondary of a center tapped transformer for Battery1 and Battery2. Again, it is a simple series circuit. Either half of the secondary can be used independently of the other half, and provide 120v AC, or the two halves can be used in series to provide 240v AC.
In the US, the dryer uses points A and B (or B and C) to provide 120 volts for lighting, timer circuit, motor circuit, electronics, and points A and C to provide 240 volts to the heating coil circuit. The dryer does not give a rat's ass what we call it - single phase, two phase, split phase or anything else - as long as it "sees" the required voltage at the necessary current.
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Whereas On Wed, 1 Oct 2003 10:43:11 +0200, "Joe 90"

It is Vab= -Vbc0, Vac$0V. Note the -Vbc, it is 180 degrees out of phase of Vab.

Don't forget there is a motor and a timer in the dryer also, and they need 120V.

They seem to allow it, so it is okay.

--
Gary J. Tait . Email is at yahoo.com ; ID:classicsat

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On Wed, 01 Oct 2003 16:45:12 -0400, the renowned Gary Tait

And generally a light bulb. Since the neutral only carries an amp or two, it could probably be recreated with a compact 230:120 control transformer or autotransformer, but I have no idea what getting that intalled to code for a Swiss residence would involve.
Best regards, Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
snipped-for-privacy@interlog.com Info for manufacturers: http://www.trexon.com
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Whereas On Wed, 1 Oct 2003 01:50:42 +0200, "Joe 90"

No, the best solution would be to hire a Swiss electrician to wire it up., or forget it and buy a Swiss/EU approved dryer, instead of trying to make the NA one to work.
--
Gary J. Tait . Email is at yahoo.com ; ID:classicsat

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The unit already works (has been working fine in Switzerland for past 2 years!) and has been checked over by a Swiss electrician for safety. I simply wanted to extend the wiring but culd not find and awg8. Thx.
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Damned difficult to believe that 10-gauge wire is unavailable in Switzerland. One might simply drive to a neighboring coutry and buy it if it is. Or is CH simply a convenient posting location? In any case, I surely wouldn't mess around with using multiple conductors to overcome the problem -- for all the reasons that others have cited.
--
John McGaw
[Knoxville, TN, USA]
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Whereas On Tue, 30 Sep 2003 20:48:43 -0400, "John McGaw"

CH is the TLD for Switzerland.
--
Gary J. Tait . Email is at yahoo.com ; ID:classicsat

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scribbled:

It would seem obvious that I knew that already. Why else would my reply state "Damned difficult to believe that 10-gauge wire is unavailable in Switzerland."
--
John McGaw
[Knoxville, TN, USA]
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Whereas On Thu, 2 Oct 2003 07:12:21 -0400, "John McGaw"

I was under the impreddsion you wern't sure if CH was indeed Switzerland, or some poor country that sold their TLD to companies for anonymous users.
--
Gary J. Tait . Email is at yahoo.com ; ID:classicsat

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