Talk:Single-wire earth return

message: :MALT is a single-phase metallic return distribution system.  While interesting for its innovative use of high voltage, it is off-topic because it is not an earth-return system, at least according to the citation, which describes using a second neutral wire.  Perhaps it should be in a different article? The removed text follows for reuse. Ray Van De Walker (talk) 07:19, 20 April 2009 (UTC)
thread_title: Removed [[MALT]] reference

message: :This text refers to a system that that does not use earth return.  While rather interesting, it is off-topic.  Perhaps it should be in a different article? Ray Van De Walker 03:53, 31 May 2006 (UTC)
thread_title:  Removed Tesla Reference from History 

message: Besides the one in the article, please read, 
* Nikola Tesla and the induction motor. CM Jarvis - Physics Education, 1970 - iop.org 
Also, a simple book search will show that this is what tesla was doing. G.book search.
204.56.7.1 15:36, 2 June 2006 (UTC)
thread_title: Tesla references

message: It's s SWER transformer, the image is taken in CANADA and the history section of the article doesn't mention that SWER lines are used in CANADA.
:: It's a single bushing transformer but we can't see the overhead line - could well have the neutral wire run overhead.  Common as dirt in rural distribution and does not in the least imply earth return. SaskPower Saskatchewan runs some SWER lines for the same reason the Australians do -remote farms many miles apart. --Wtshymanski 17:59, 18 July 2006 (UTC)
replies: text: (following comment also posted earlier on talk:split-phase) looking at http://wearcam.org/christina/billru_cottage/d325.jpg which appears to be a larger view of the photo in the article and some of the related images on http://wearcam.org/christina/billru_cottage/polemount.htm it looks like the horizontal wire in the picture is a neutral of some kind with the phase wire being higher up on the pole. Plugwash 00:13, 19 July 2006 (UTC)
thread_title:  Take a look at the Image:Polemount-singlephase-closeup.jpg 

message: Obviously it only requires half as many conductors as a two wire system, and 1/3 as many conductors as a 3 wire system -- but the cost of the wire itself is one of the smaller costs in a electric power transmission system.
The article gives 2 other reasons SWER costs less than 2-wire systems:
* SWER's high line voltage and low current permits the use of low-cost galvanized steel wire. Steel's greater strength ...
Huh? No, steel is not stronger than the material used in 2-wire systems.
And 2 wire systems also use high voltage / low current.
* SWER also reduces the largest cost of a distribution network, the number of poles. Conventional two wire or three wire distribution lines have a higher power transfer capacity, but can require seven poles per kilometre, with spans of 100 m to 150 m. SWER ... reducing the number of poles to 2.5/km.
OK, so we go from 7/km to 2.5/km. That's wonderful, but why?
Why does SWER need fewer poles?
It can't be because the cables are stronger.
(The material used in SWER systems isn't any stronger than the steel cables used in 2-wire systems).
I could speculate that with 2 or more wires, we need more poles to keep the lines from swinging into each other and sparking. While with 1 wire, we just need enough poles to keep the lines from hitting the ground.
But perhaps there is some other reason?
--70.189.77.59 21:04, 21 October 2006 (UTC)
replies: text: This information is from ruralpower.org, which has Conrad Holland P.E., and confirmed by Stone Power A.B. (likewise an engineering group.)  I suspect that galvanized wire without cladding has a somewhat better strength-to-weight than clad wire.  Steel is stronger than either copper or aluminum, you know.  But the information is from them, and they actually build these things.  I just write articles as a hobby. Ray Van De Walker (talk) 08:15, 20 April 2009 (UTC)
thread_title:  SWER cost 

message: They do occur, the question is how much, and what's morally acceptable.
"The advantage of such schemes is saving money for a second conductor, because the saltwater is an excellent conductor. Some ecologists claim bad influences of electrochemical reactions, but they do not occur on very large underwater electrodes."
The amount of reaction occuring is relatively small compared to what's expected from the line's power rating, because most of the energy in a high voltage line is delivered by high voltage and relatively small currents flow, so the power P=I*V is large, while the power loss, dependent only on current and resistivity of wire, I^2Rstays low. I.e. if the same line carried 800,000 volts, or 101 volts and 1 amps over a 100 ohm line, the IR voltage drop in both cases would be dV=IR=1*100=100 Volts, delivering 1 volt on the other end of the wire out of a 100 V input, or 99% loss, compared to 799,900 output out of an 800,000 V input, or less than 1% loss. This is the reasoning for high voltage, limiting the amps that cause voltage drop, but it's also a reasoning to limit the electrochemical reactions, which as voltage independent and only depend on current, based on Faraday's law of electrolysis.
m=1/F * A/n * I*t
where
F=96485 Coulombs/mole charge, the Faraday constant
A=atomic mass, 35.5 g/mole for chlorine atoms from seawater, 16 g/mole for oxygen
n=charge per atom, 1 for chloride ions, 2 for oxygen ions
I = amperage, t=time in seconds
So an 8 amp line would generate m=1/96485*35.5/1*8*(24*60*60)=254 g of chlorine gas in a day, equivalent to dumping  25,400 g of 1% wt bleach, or about 25 kg, 25 liters,  about 6-7 gallons of straight bleach into the ocean per day at the titanium cage site in question. The sea and sea biosystems buffer and nullify most of these effects - the ocean is a big place - though there is a theoretically limited buffer capacity, how much is too much. It would be nice to have a study on how much this affects a local ecosystem, compared to, say, human fishing and fish eating, or waste treatment plant effluent releases, on a relative scale, on a dollar per dollar basis - if you can put a dollar sign on damage to the environment due to fishing - and what's acceptable. Humans do inflict some damage on the environment to sustain themselves, including taking over areas from wildlife for agriculture, hunting, fishing, etc., question is how to optimize actions to get the least environmental damage for greatest benefit. For instance fishing is a "natural" process that's been around for millions of years, while chlorine and oxygen induced damaged dna might induce ecosystem changes that are far too great compared to, say, sunlight uv and cosmic ray and seawater uranium decay inflicted dna damages. By the way most public utility drinking water is either chlorinated, oxygenated/ozonated, or treated with UV, to destroy most organisms, and such water, if allowed to stand for long, the organisms that haven't decayed remultiply and the water becomes stale. It's amazing how life is both so fragile and so resilient at the same time. Sillybilly 13:03, 8 November 2006 (UTC)
thread_title:  Some ecologists claim bad influences of electrochemical reactions, but they do not occur on very large underwater electrodes. 

message: It's been a while since I last looked her and the article has become a very good reference piece on SWER.  It has presented what can be a very confusing engineering concept in simple terms.  Well done.  Lumberjack Steve 22:42, 24 January 2007 (UTC)
replies: text: Not quite sure what you mean here - in terms of the frequency it will transmit at whatever is generated 50Hz or 60Hz being the most common Lumberjack Steve (talk) 01:26, 29 November 2007 (UTC)

text: I added some clarifying text; I myself heard of Tesla's scheme long before I heard of SWER, and I was initially confused. Ray Van De Walker (talk) 08:28, 20 April 2009 (UTC)
thread_title:  Good article 

message: Please cite any references or sources. (January 2008) J. D. Redding 15:11, 9 April 2008 (UTC)
replies: text: The safety discussion is a paraphrase of Mandeno's article, and reviewed by Conrad Holland, P.E., both already cited.  If you mean "regulatory" issues, it's the National Electrical Code (obvious to me, I guess), and it's not available on line because it's copyrighted, and the copyright is enforced for safety reasons.  It can be purchased here:  Ray Van De Walker (talk) 08:16, 20 April 2009 (UTC)
thread_title: Safety references or sources

message: Please cite any references or sources. J. D. Redding 15:13, 9 April 2008 (UTC)
replies: text: The reliability references are already cited: Mandeno, and also Holland. Ray Van De Walker (talk) 08:00, 20 April 2009 (UTC)
thread_title: Reliability references or sources

message: Please cite any references or sources. J. D. Redding 15:13, 9 April 2008 (UTC)
replies: text: The power quality references are already cited: Mandeno, and also Holland. Ray Van De Walker (talk) 08:00, 20 April 2009 (UTC)
thread_title: Power quality

message: Please cite any references or sources. J. D. Redding 15:13, 9 April 2008 (UTC)
replies: text: The upgrade recommendations are already cited, see the Stonepower A.B. web site. Ray Van De Walker (talk) 08:00, 20 April 2009 (UTC)
thread_title: Upgrading a SWER line references or sources=

message: Merging sections and putting one tag ... J. D. Redding 15:13, 9 April 2008 (UTC)
thread_title: Merging sections

message: There's a section "use in interties", but with no link to what an intertie is, and searching on Google it appears that entire HVDC lines such as the one on the West Coast of the US are called interties - that's the first result and this page is the second result searching for "intertie electricity distribution". Could someone explain what the definition of an intertie is in comparison to other transmission/distribution systems? Miasmic (talk) 21:26, 10 August 2010 (UTC)
replies: text: An intertie allows power to flow from one grid to another.  It's usually metered so the utilities involved can exchange money for power.  An intertie provides alternative or inexpensive power in case generators fail, or lack needed capacity.  Interties can be economical when a grid has cheap power and can afford to sell it to neighbors. Ray Van De Walker 15:15, 10 August 2011 (UTC)
thread_title: Interties

message: In the section "Mechanical design" para 3, it says,
"In Thailand the poles only needed to be 1.3m high to allow for the safe passage of the locals."
This sounds like a rather feeble racial joke.   Darkman101 (talk) 00:02, 22 May 2014 (UTC)
thread_title:  Is this vandalism ? 

message: I think that passage ment "open floating star", or which ever is the most correct name for this now rare configuration. To make it clear, this can be used to provide three phase power with only two conductors; who said the pahse angles must be even if you allow single phase loads in the medium voltage network anyway. The linked Two-phase is almost completely historic.
:Some helpful editor has changed it to the correct, still-used "split-phase". Ray Van De Walker 02:24, 23 December 2015 (UTC)
replies: text: Yes.  My house is wired this way. Ray Van De Walker 02:24, 23 December 2015 (UTC)

text: I've never been involved with the actual engineering decisions, but I do know that there is an effective, more standardized substitute distribution drop that would serve the same purpose as three-phase earth-return. Three-phase delta is widely used in place of three-phase wye. Delta has no need to distribute a neutral wire for current return and the safety ground is provided locally, or in a substation as a true earth ground. Ray Van De Walker 02:24, 23 December 2015 (UTC)
thread_title:  Two phase reference 

message: Mention if  is ever used on the user side of the power meter. e.g., by individual farm owners. Jidanni (talk) 08:28, 29 May 2019 (UTC)
replies: text: I have never heard of such an application. Though physically possible, it might contradict local safety regulations. In most areas, a government-licensed engineer is permitted to sign-off on the safety of unusual installations. Ray Van De Walker (talk) 23:20, 2 August 2019 (UTC)
replies: text: I'm thinking jungle water pump. But my tests with a light bulb showed that a copper return wire made a brighter light... Jidanni (talk) 15:27, 5 August 2019 (UTC)
thread_title:  On user side of the power meter 

message: This is a great piece of trivia, but it's a bit disingenuous to claim that there were no other factors. The cited article actually says that the value of 12 m comes from wanting long, unbroken sightlines between the poles. Where giraffes are mentioned, it says only that "conductor supports" (synonymous with "poles"?) had previously caused problems when placed < 5.2 m off the ground. SuscipiamSingularitatem (talk) 01:42, 9 April 2021 (UTC)
thread_title:  re: Mechanical design section, pole height influenced by giraffes