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I added a section outlining the balanced wye conneced and delta connected modes. The circuit diagrams with generator side offer more to the reader than the other two delta and wye diagrams. The voltage and current derivations add more to the story of where the VLL and VLN conversions come from than in the single phase load section. I would consider also consolidating the single phase load section moving its Unbalanced section as a second part to the balanced circuits. — Preceding unsigned comment added by Jaredmporter (talk • contribs) 22:38, 27 November 2013 (UTC)[reply]

Sounds like a good idea. Minor point is to be careful of the WP:TONE...just say what it is, rather than saying that "we see" it or that something is good to note. DMacks (talk) 23:00, 27 November 2013 (UTC)[reply]

That's a neat equation-alignment feature, no? DMacks (talk) 05:23, 2 December 2013 (UTC)[reply]

yes, it is. 85.110.119.56 (talk) 06:03, 3 December 2013 (UTC)[reply]

Old discussions, some of which haven't been active in years, can be found in the talk page archives linked above. --Wtshymanski (talk) 00:40, 29 March 2014 (UTC)[reply]

Can we clear this up? It's not clear why my edit was reverted. To my knowledge, the standard electrical install required for most home-loan financing is a 200-A 2-phase system. There are other details if you look farther up the distribution network but at a residence, there are 2 phases and a neutral. So... what's the reason for the reversion? — Preceding unsigned comment added by Neffk (talk • contribs) 19:41, 5 May 2014 (UTC)[reply]

It's fed from one of the three phases of the distribution, which is converted to a split-phase. The result is two opposing phases (180°, or + vs – of same "phase"), not two of the three three-phase (120°) phases. File:Polemount-singlephase-closeup.jpg is pretty standard last hop before residence. Notice one primary-side bushing, and two secondary (plus center-tap neutral). DMacks (talk) 19:57, 5 May 2014 (UTC)[reply]

It looks like two phases, but in electric-speak it counts as one. Phases that are 180 degrees apart don't count as additional phases. I agree it is a funny rule. Note also that you could use center-tapped transformers on a three-phase wye system, and, I believe, it would still be three, and not six. I don't have any reference for that, though. Gah4 (talk) 02:19, 3 April 2015 (UTC)[reply]

The standard supply to an American home is 3-wire single-phase. It's not clear what the reference to 200A for home financing is referring to though. There are thousands of homes across the U.S. still running on 100A (or lower) services, and that really has nothing to do with financing. Some financers might balk at specific types of equipment which have been shown to have problems (e.g. some Federal Pacific panels), but that's a different matter. 97.84.107.236 (talk) 16:08, 23 November 2015 (UTC)[reply]

"While a single phase AC power supply requires two conductors (Go and Return), a three phase supply can transmit three times the power by using only one extra conductor. This means that a 50% increase in transmission cost yields a 200% increase in the power transmitted. [3]"

That depends on how the sytem is set up and under what condition power is transfered and measured. The transfer may be 3 times or squareroot(3)=1,73 times the transfer of two phase connected loads. KjellG (talk) 15:04, 28 May 2014 (UTC)[reply]

For a balanced three-phase delta system, limited by voltage to ground (dielectric breakdown) and current (thermal), the three-phase system allows three times the power. For an unbalanced system, three phase wye, or other limitation, it will be less. But then it says "can" not "always will be". The 50% increase and 200% increase are hard to read, even if correct. Gah4 (talk) 13:50, 3 April 2015 (UTC)[reply]

The principle behind this is that a 3-phase system makes optimal use of the conductors (given a maxium permissive voltage) by using all of them at the maximum permissible voltage, while single phase and corner grounded delta systems make less use of them because they have a neutral. The same may be obtained with a single phase system, it is just a matter of using both conductors at the same voltage (for instance, by grounding the center tap of a transformer). I have also reworded the paragraph so that it is clear that it is capacity what increases relative to material used. Mario Castelán Castro (talk) 18:57, 3 April 2015 (UTC).[reply]

Hello. This article and three phase are about exactly the same topic. Three phase explains the mathematics of a three phase system, but I think than that should be explained here as well, since it's a single topic. Under the relevant policy on merging I think that this is an instance of overlap. I can understand having several articles on a topic when it's very lengthy and complex, like relativity (physics) and introduction to special relativity but this is not the case here. Regards. QrTTf7fH (talk) 16:10, 4 August 2014 (UTC).[reply]

Go for it. Once you eliminate the math typesetting from three phase, there's not much content that isn't duplicated here or better off here. Wikipedia is not a textbook and showing all the derivations is a job for a textbook, not an encyclopedia. --Wtshymanski (talk) 02:50, 5 August 2014 (UTC)[reply]

As an undergraduate physics student and high-functioning autistic, these articles should be kept separate as the theory and application in the real world are quite different even though there is significant overlap. An analagous situation would be microeconomics and macroeconomics. The size and scope of the two articles here are different enough that both should be improved and contain links to each other. Another crucial point here is that physicists define electricity and mathematically treat it from a different perspective as electrical engineers. Interestingly, the first comment above mentions both special relativity and general relativity and from the perspective of the most general audience, certainly two separate articles are more than justified. Possibly the two articles could/should be merged but not until the content is both improved and simplified as to complexity so the general reader level is at least as supported as the electrical engineer reader. Cheers. Gf1422 (talk) 08:41, 1 September 2014 (UTC)[reply]

Hello, I think it is very badly written and is confusing. — Preceding unsigned comment added by 202.6.136.224 (talk) 06:01, 10 February 2015 (UTC)[reply]

I think they work well separate. Very litle math is required to actually use three phase power, mostly knowing where to put the square roots of three. I am sure that the people who string up long distance power lines don't do much of the math. If one does want the math, there is a place to find it. Gah4 (talk) 00:58, 14 May 2015 (UTC)[reply]

Oppose This merger proposal has been up since August of 2014, and though there has been little discussion here, it is obvious that there is no consensus. My personal opinion is that Three Phase should be its own article, as it is its own mathematical and physical concept and deserves its own discussion. Meanwhile, the three-phase electric power article also should be its own article, as it is the most widely used form of electricity distribution in the world. Since this proposal has been up for a very long time, and there is not consensus, and it has been sparsely discussed for several months, I think this fits the description of a failed merger proposal (see Step 4 on that page), so I'm removing the merger tag from the article. If anyone strongly disagrees, please start a new discussion! Spiral5800 (talk) 17:34, 23 June 2015 (UTC)[reply]

Suggest the reference to IEC 60446 is cleared and the correct reference to IEC 60445 is put in (change since 2010), this is regarding color coding of wires Sigurdurs (talk) 09:27, 29 April 2015 (UTC)[reply]

Done, but I have left the link to 60446 in place since that page has the information. IEC 60445 is currently just a redirect to List of IEC standards. SpinningSpark 15:44, 29 April 2015 (UTC)[reply]

There is a comparison of three phase delta with one phase, hot and neutral, in power transmission efficiency. It would seem more fair to compare to two-wire single phase with grounded center tap. Also, is phase-to-phase voltage a more useful comparison than phase-to-ground? Gah4 (talk) 21:00, 13 May 2015 (UTC)[reply]

I don't understand why you want to compare to the rather unusual single-phase centre-tapped (split phase). The comparison between single-phase two-wire and three-phase three-wire on a power per conductor basis seems perfectly valid to me. On the phase-phase voltage issue, the limiting factor on overhead lines is likely the voltage across the insulators between the lines and the pylon, that is, the phase to earth voltage. The phase to phase voltage may be significant in an underground cable however. In any case, my purpose in the edit under discussion was simply to restore a reference which properly verifies the text in the article, not to try and justify the validity of the comparison. If you want to make a different comparison, you are welcome to look for a source that it can be cited to. SpinningSpark 22:18, 13 May 2015 (UTC)[reply]

If the question is the efficient transfer of power over some distance, and the restriction is phase to ground voltage, then I see no reason why one wouldn't minimize the phase to ground voltage by using a center tapped transformer. On the other hand, if you do want to compare phase and neutral, a fair comparison might be to three phase wye. As far as I know, in the case of one phase to neutral, it is usual to use earth ground return, which also saves on wire cost. You are probably right about insulators being the limit, though at some point corona discharge off the wires becomes important. Gah4 (talk) 00:50, 14 May 2015 (UTC)[reply]

I chose to add some extra information about high phase order systems dealing with the pros and cons of why they could be practical but aren’t. In addition, I wanted to make it clear that while 6 or 12 phase systems are indeed more efficient, there are clear drawbacks that make it impractical today.

• High-phase-order systems for power transmission have been built and tested. Such transmission lines typically would use six phases or twelve phases in order to maintain both the cancellation of triplen harmonics and forgoing the need for a neutral wire for return. Higher-phase-order systems provide more efficiency and smoother power transfer. High-phase-order transmission lines allow transfer of slightly less than proportionately higher power through a given volume without the expense of a high-voltage direct current (HVDC) converter at each end of the line. However, with these benefits come issues of cost, equipment, and analysis. Higher phases require an increased number of buses and conductors, in addition to to more power transmission lines. These lines also need to be transposed significantly with one another-for example, a six phase power system would need to transpose the line a total of six times to maintain balance. Analyzing a system with higher phase is also much more complex than a three phase network; therefore, maintenance of a higher order system is more difficult to comprehend. Additionally, the increase in efficiency of one phase to three phase power is much more significant than the increase in efficiency of three phase to a higher phase; as a result, it is at three phase power that we find the optimal amount of power efficiency for cost. It is also important to note that there are little to no advantages for a four or five phase power system compared to a three phase system as these systems are unable to deliver constant power; therefore, only higher order n-phase systems that are multiples of three should be considered as being advantageous to the conventional three phase system.

Sidd26 (talk) 03:05, 9 December 2015 (UTC)[reply]