Internation standard

| To the best of my knowledge, there was no worldwide conference on | selecting a global electrical standard as there had been for setting | the world's time zones (The French insisted that the prime meridian 0 | degrees longitude must run through Paris, but the British held out for | Greenwich, and won!) . Perhaps, at the time, the big industrial | concerns like Siemens were interested in protecting their markets, but | I think the choice was made without even imagining a global market for | electrical products. In Europe, even though the voltage and | frequency were standardized throughout the continent, every single | country had their own unique plug and socket arrangement that persists | to this day.

And what was the frequency dependency of the primary consumer electrical product of the day? None. It was the light bulb. Industry had some concern since much of their usage was motors. But motor systems could be engineered around it easily enough.

| I still have trouble understanding why Japan is at 100 volts and half | the country is at 50 Hz, the other half at 60 Hz. Does anyone know | the particulars?

I'm not sure about the 100 volts, but the frequency difference could have been just from two major hold outs. At the time they didn't need to form a shared grid, so the remaining issue would be dependency on stuff that used the power. And it's not the critical.

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phil-news-nospam
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Thanks.

You'd need high ceilings for that as well. I noticed while searching for those sections of the NEC, they require 277 volt light fixtures to be

(since they listed the voltage as 277, wonder if you could 'cheat' and 'ask' the utility to provide a slightly lower feed voltage :-) )

Reply to
Michael Moroney

| snipped-for-privacy@ipal.net writes: | |>| What's 210.6(C)(6) have to say? I can't find that portion online. | |>In the 2005 draft it says: | |>Cord-and-plug connected, or permanently connected, utilization equipment. | | Thanks. | |>And if it weren't for the fact that I dislike fluorescent lights, I might |>cheat a little and get some 277 volt lights. There are incandescent bulbs |>made for 277, but it's jut not worth the trouble. | | You'd need high ceilings for that as well. I noticed while searching for | those sections of the NEC, they require 277 volt light fixtures to be |>8' from the floor.

How high do 220-240 volt light fixtures need to be in Europe?

| (since they listed the voltage as 277, wonder if you could 'cheat' and | 'ask' the utility to provide a slightly lower feed voltage :-) )

I don't know that I would be getting 277 from the utility at all. If I could, great. If not, I have to transform the voltage myself. What I could do is make sure everything is rated for the full 277 volts, then just wire it through a transformer at the panel (a separate subpanel at

277 volts). If I sell, I just replace the 277 volt bulbs with 120 volt ones, and remove the transformer.

But it's not really worth the trouble. It's just a dream I have of a better electrical system. Had it been that way all along, the NEC would be dealing with it, and it would even be safer than now because it would be expected. A lot of the danger of high voltage isn't the voltage per se, but the expectation of a lower voltage. If you think the bulb socket has 120, but it has 277, surprise! I think the NEC frowns on such things. Having 230 volts or so in a light socket in Europe is not surprising to Europeans.

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phil-news-nospam

yeah, I noticed the insulators between the wires were smaller than those from them to the tower, and figured that being fairly close to being in phase the voltage between them would be lower, though I didn't work out the math.

Reply to
Michael Moroney

Actually, the primary consumer electrical product of the early years of the electrical age was the iron (see "The Electric City" by Harold L. Platt -1991), but you are correct in that it did not have a preferred frequency.

At one time, there were many satisfactory power distribution systems at 25 Hz. This was thought to be the ideal frequency for consumer and small industrial motors, transformers, etc. The New York Transit Authority used 25 Hz into the 1990's for distribution and rectification to DC to power the trains.

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It turns out that incandescent light bulbs do have a frequency dependency... The lower frequencies caused excessive flicker in the lower wattage lamps. Hence, 25 Hz was deemed unacceptable for residential consumer use and the higher 60 Hz value was picked for North America.

Beachcomber

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Beachcomber

In six-phase 'double-wye' the phase-to-neutral and phase-to-immediately-adjacent-phase voltages are equal. Ref IEEE Std C57.12.70 §6.

?s falke

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s falke

Hepcats call this 6ø/12ø stuff "high phase order"

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?s falke

Reply to
s falke

On Fri, 23 Apr 2004 18:11:56 +0000 (UTC) Michael Moroney wrote: | snipped-for-privacy@ipal.net writes: | |>Yes, 6 phase on the left, 12 phase on the right. I don't really know where |>it is. Supposedly by having more phases like that, wire spacing is easier |>to do. At a 30 degree phase angle, the potential between conductors is a |>bit more than half the line to ground voltage. So if the voltage from each |>line to ground is 69000, then from line to cloest line is just 35717. | | yeah, I noticed the insulators between the wires were smaller than those | from them to the tower, and figured that being fairly close to being in | phase the voltage between them would be lower, though I didn't work out | the math.

Hitting 35717.028224148 requires the math. But you can simply visualize the vector diagram right on that 12 phase attachment and see the reduction.

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phil-news-nospam

On Fri, 23 Apr 2004 22:22:17 GMT s falke wrote: | | "Michael Moroney" wrote: |>

|> >Yes, 6 phase on the left, 12 phase on the right. I don't really know where |> >it is. Supposedly by having more phases like that, wire spacing is easier |> >to do. At a 30 degree phase angle, the potential between conductors is a |> >bit more than half the line to ground voltage. So if the voltage from each |> >line to ground is 69000, then from line to cloest line is just 35717. |>

|> yeah, I noticed the insulators between the wires were smaller than those |> from them to the tower, and figured that being fairly close to being in |> phase the voltage between them would be lower, though I didn't work out |> the math. | | In six-phase 'double-wye' the phase-to-neutral and | phase-to-immediately-adjacent-phase voltages are equal. | Ref IEEE Std C57.12.70 ?6.

Does IEEE talk any about twelve-phase?

The six phase configuration, of course, is with each angle at 60 degrees which will do same voltage between each phase.

What I find interesting is that the cross section of that transmission line is a representation of the phase vector diagram. Imagine doubling the 12 phase system to 24 phases, nearly cutting the line to line voltage in half yet again. Then split it further to 48 phase, then 96, then 192, and so on. You'd be approaching a solid tubular conductor that way.

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phil-news-nospam

On 24 Apr 2004 07:05:24 GMT snipped-for-privacy@ipal.net wrote: | On Fri, 23 Apr 2004 18:11:56 +0000 (UTC) Michael Moroney wrote: | | snipped-for-privacy@ipal.net writes: | | | |>Yes, 6 phase on the left, 12 phase on the right. I don't really know where | |>it is. Supposedly by having more phases like that, wire spacing is easier | |>to do. At a 30 degree phase angle, the potential between conductors is a | |>bit more than half the line to ground voltage. So if the voltage from each | |>line to ground is 69000, then from line to cloest line is just 35717. | | | | yeah, I noticed the insulators between the wires were smaller than those | | from them to the tower, and figured that being fairly close to being in | | phase the voltage between them would be lower, though I didn't work out | | the math. | | Hitting 35717.028224148 requires the math. But you can simply visualize | the vector diagram right on that 12 phase attachment and see the reduction.

I ran the calculations on more phases, to extreme, based on 69000 volts:

phases voltage

------- ---------------- 6 69000.00000000 12 35717.02822415 24 18012.61452637 48 9025.63183376 96 4515.23342940 192 2257.91896446 384 1128.99726534 768 564.50335562 1536 282.25226818 3072 141.12620789 6144 70.56311317 12288 35.28155774 24576 17.64077901 49152 8.82038952 98304 4.41019476 196608 2.20509738 393216 1.10254869 786432 0.55127435

1572864 0.27563717 3145728 0.13781859 6291456 0.06890929

and based on 1000000 volts:

phases voltage

------- ---------------- 6 1000000.00000000 12 517638.09020504 24 261052.38444010 48 130806.25846029 96 65438.16564355 192 32723.46325297 384 16362.27920787 768 8181.20805247 1536 4090.61258233 3072 2045.30736068 6144 1022.65381403 12288 511.32692372 24576 255.66346395 49152 127.83173224 98304 63.91586615 196608 31.95793308 393216 15.97896654 786432 7.98948327

1572864 3.99474163 3145728 1.99737082 6291456 0.99868541

Now, who would like to construct a tube with 6291456 tiny parallel wires over a length of a transmission line, or the transformer array needed to convert the phases. :-)

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phil-news-nospam

To get more power over an existing limited right-of-way, wouldn't it be more economical to just build higher towers with conventional

3-phase conductors at higher voltages? (With the understanding that there might be height restrictions near airports, etc.)

Asthetically, I think these HPO towers would "freak-out" owners with property adjacent to the right-of-way. To me, transmission towers and substations are usually a thing of beauty. I think these things are a bit on the ugly side, however.

Beachcomber

Reply to
Beachcomber

| To get more power over an existing limited right-of-way, wouldn't it | be more economical to just build higher towers with conventional | 3-phase conductors at higher voltages? (With the understanding that | there might be height restrictions near airports, etc.) | | Asthetically, I think these HPO towers would "freak-out" owners with | property adjacent to the right-of-way. To me, transmission towers and | substations are usually a thing of beauty. I think these things are a | bit on the ugly side, however.

I rather like them, especially at 12 phases.

I'd be one of those who would "freak-out" if an adjacent transmission line were doubled in height and voltage. But doubling or quadrupling the number of wires in an HPO line at the same height would not. When I would have visitors over, I'd tell them made up stories about how the wires are used to entrap magnetic fields, or it's a design they got from space aliens, or such.

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phil-news-nospam

...

There's another use for such "multiphase" transmission lines. Right now long AC transmission lines are unstable due to phase shift, but the long wavelength at 60 Hz (5,000 km) means it takes a length of 1666.666 km to by one complete phase (A becomes B, B becomes C, C A), so there are problems if a substation is fed through routes of different lengths. But with 6291456 phases :-) the phases shift by 1 in about 112 cm, so two or more routes of different lengths can be matched to that distance precision.

Reply to
Michael Moroney

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