|>I'd like to know when the US went to 120. Did the 440->460 and 460->480 |>steps happen at the same time as 110->115 and 115->120? | | I remember the voltage being listed as 117V at one time. So maybe there | was a 115->117V transition, or was it 110->117V at once?
I've seen that, too. I've also seen things listed with 125V and 127V and even 130V and 140V. In some cases I think it's "max volts". Some light bulbs do come in 130V rating, probably to extend life.
| I'd guess 440->460->468->480 happened as the same time as the | corresponding 110->120V transitions, as I'd assume they made the | conversion one substation at a time (possibly by simply changing taps), | rather than replacing zillions of perfectly fine pole pigs. Also, I | remember they had 'brownouts' (voltage decreases) during the energy crises | of the '70s (rather than rolling blackouts like they'd do now if they had | to), and I'd assume that was also done by simply changing taps.
But are brownouts really effective? Motors in particular, and most things with switching power supplies, just compensate with more current. With more current downstream, line losses increase. So unless there are enough things like light bulbs that go down in current to account for the current losses in what goes up, a brownout could these days have the opposite effect of what is desired. Maybe that is why they are doing blackouts. Soon more people will be installing energy reserve systems to deal with that, which means more current when the power is on.
|>I do know that before Edison, there were several suppliers of electricity |>around the US (had been for many years) and the systems were configured |>in all kinds of ways, different voltages and frequencies. I'm sure the |>same must have been in Europe. | |>I'm also curious how the transition happened after Edison in terms of |>getting the country on the same voltage. Edison sure didn't get it on |>DC, so I doubt he played a significant role in having 110 volts AC. But |>maybe it was his idea of the 110/220 split combined with 220 being in |>use in Europe (was it that _common_ at that time frame?) that make it |>a popular choice as more electrical supply systems were being put online |>in America. | | I thought Edison with his 110/220V DC system was first (other than | possibly some small systems of no consequence) and when DC proved | impractical due to inability to send it long distances, they kept the | 110/220V configuration for compatibility but went AC for the most part, | though there were many incompatible systems in the mean time.
I recall seeing some documention of 220 volts being in use before Edison set up his system. Remember, he did not invent the light bulb; he just improved on it to make it practical enough for common use (e.g. don't need to change the bulb every day). Electric lights were in use before this time, as were motors running on both DC and AC. The really great invention, though misused for a while, was the transformer. That's what killed DC.
As for the 110/220 split, I am more inclined to believe it was part of his light bulb "improvements". At a lower voltage, you can have a thicker filament. I suspect he split the voltage because it gave him even more of an edge on light bulb service life. He surely understood that lower voltage was better for the bulbs, but harder to deliver, and split the power to gain the advantage of lower voltage for the bulbs while keeping the deliverability of the higher voltage. Unfortunately with DC at the time, 2:1 was the best he could do. AC plus the transformer ultimately won, but by then the light bulb had gotten good enough that there was not a major need to go even lower in voltage. Had things shifted a bit, such as AC taking over sooner and light bulbs getting better later (such as going to the tungsten filament), we might well have seen a further reduced voltage delivered into the building based on an outside transformer to step the "street voltage" down. Perhaps it might have ended up with 50 volts for lights and 500 volts on the street. If Edison had accepted AC and gone with that (and paid off some patent royalties for Westinghouse, Siemens and others, which I think is the real reason he stayed with DC) he might well have managed to light up all of New York City and more on his own.
I don't know if Edison was the choice of "220" or not. I'm inclined to think not. I suspect the number came from one of Siemens, Tesla, or Westinghouse. And I suspect Tesla would have chosen it because of its easier three phase calculations (e.g. you could use whole numbers and get fairly accurate results). It's not the only such number, and not even the best in terms of whole number closeness, but it would be an attractive number in the desired voltage range. If this was the motive for the choice, some of the other better choices could have been: 97Y/56 168Y/97 265Y/153 362Y/209 627Y/362 989Y/571
It could simply have been the arbitrary choice of one of the first electricity producers and it just happened to catch on.
But I don't think Edison had any influence on the choice Europe made. If he had, wouldn't they have gone with his split system?
|>And how did Canada come to be using the 600 and 600/346 volt system, which |>I presume to be originally 550 (and 550/318 if wye came before the voltage |>change). It's not an unknown voltage in the US, but very rare. Canada |>does have a lot more 480/277 than the US has 600/346 though. | | I know this: I once worked in an old mill complex that used electricity | in the late 1800s. An old generator was on display. If I remember, the | date on the nameplate was 1897. It ran at 40 cycles per second. I also | know they used 550 volts (delta probably, knob-and-tube wiring with 3 | conductors was used) for several vintage elevators. A single circuit fed | by a backwards 480-120 transformer with taps fed several elevators. An | electrician neighbor once mentioned 550V to me. It may have been common | in the early 20th century "mills".
Back when things were not interconnected, and there was little vision of that kind of thing (a grid) ever happening, and there was little if any mass market in electrical appliances for the "common man", the frequency could be freely chosen based on whatever motor speed was needed. So there were a lot of choices made. And if you're designing the electrical system around the utilization, then voltage becomes as easy to choose as frequency.
I do suspect that the choice of 100 volts in Japan was influenced by so much of the country being on 50 Hz and either wanting to use US transformers or use the US transformer designs to get started. But this is really just speculation on my part. It could also have been a war time thing that stuck.