Google seems to have let me down on this topic, and I am starting this thread here to avoid hijacking another one where Q.E.D. and I seem to have a minor disgreement.
The questions are: What is the frequency of consumer-grade A.C. powerlines in other parts of the world than the U.S.? 60 hz is the U.S. standard, but is 50 hz used anywhere else?
And if not currently (heh), was 50 ever commonly used in the past?
I recall vividly that 50/60 hz (actually, “cps” years ago before hertzes were invented) was displayed on many transformers and consumer electric/electronic products years ago. IIRC, “60 hz, 50 hz in Canada” is so well ingrained in my mind that I would never question it if Q.E.D. hadn’t. Does Canada use 50 now or did she ever? And if so, when was the switch made, and why?
Numerous links about EMF/cancer links, pro and con, use the phrase 50/60 without making any distinction. I even found some NZ/AU researchers with a paper given in Greece about a study using 50 hz but no mention of 60. So does Australia and/or New Zealand and/or Greece use 50?
Do we have any power supply experts handy? It should be a simple question for you.
[url=http://kropla.com/electric2.htm]Here is a listing of powerline frequencies currently in use aroudn the world.
As for the 50/60 Hz marking on transformers and power supplies, this is still fairly common. It’s fairly trivial to engineer a transformer to work reasonably well within a small range of frequencies. I’ve even seem some rated for 50-400 Hz, for use on land systems as well as on aircraft.
Great link; just what I hoped for and couldn’t find thru Google. Interesting, Japan uses both 50 & 60. It even seems that, in terms of the number of countries that use it, 50 is slightly more popular.
Now the only thing left to answer is when Canada first used 60. Got an historical chart up your sleeve?
There’s one anecdote that 50hz was used by early European networks because it was a Metric-friendly multiple.
It seems oddly coincidental that the Hoover Dam would run on an even multiple of Niagra’s transmission frequency. I wonder if 250RPM wasn’t a common specification for hydro generators–either because of some efficiency at that speed, or just because that’s what was available. Anyone know the original generation frequencies of other hydro plants?
I’m not sure buy that Hoover Dam story. I can find only one reference to it, and that’s justanother site quoting that message board post. There’s no mention of it in my copy of the Electical Engineer’s Reference Book (1945), though that’s hardly surprising.
Here’s something interesting. From Loren Cook’s Engineering Cookbook, A handbook for the mechanical designer (PDF): (1999)
Looks like a serious reference work, but seems to clash with the other data offered in this thread. I wonder if this is just a myth that belongs in Snopes.
Canada is most definitely 60 Hz… otherwise our analog TV sets would have a real fun time with US broadcasts, among other things. The Canada and the US are pretty tightly integrated electrically (which is why the blackout last summer affected both of us).
I remember reading about the 25-Hz stuff, but I’m surprised it stuck around as late as 1957; I thought it was replaced by the late forties at the latest. I’d be very surprised to learn that Canada ever used 50 Hz. I’m not saying that might not be true, just that I’d be surprised.
Incidentally, Japan is split: half uses 50 Hz, and the other half uses 60 Hz.
I think the incorrect idea that Canada uses, or at least used, 50 Hz power comes from two bits of commonly known information: 1) Canada was at one time part of the British Empire and 2) The UK uses 50 Hz power. Someone who knows both of these things might assume, therefore, that Canada uses 50 Hz power too.
Some parts of Boston, MA (USA) still were serviced by DC as late as 1970. I recall hat Beacon Hill (a ritzy part of Boston) was converted totally to AC by 1978. A wealthy lawyer was holding things up-he wanted Boston Edison to pay to re-motor his DC elevator to work on AC. He sued them because they would not pay=so the whole neighborhood had to wait.
Actually, DC has a few advantages:
-very low electrical noise
-motor-driven appliances with DC can be smaller
