60 Hz Vs 50 Hz

Just because. It developed over time. Oh, and the US is not the only country using 60Hz.

Charles Perry P.E.

This is due to the geo-magnetic properties of the soil in the USA.

sQuick..

Most likely 60 came to the U.S. because Westinghouse (Tesla) found it produced the least flicker in lamps.

One thought is that the 50 cycles were originated by AEG in Germany which controlled the European market.

It is because the US is a richer nation than any of those in the EU and can afford more Hz's.

>

On Thu, 9 Mar 2006 02:14:07 -0000, "sQuick" Gave us:

If you are not joking, then you are retarded.

On Thu, 09 Mar 2006 02:44:25 GMT, Rich256 Gave us:

More likely because 3600 rpm generator speed is easily divided up in the 360 degrees that make up a full circle. The windings, and many other aspects of system design are quite a bit easier.

The math may be easier, but to say a particular frequency was chosen because merely a set of mathematical calculations was easier is nonsense.

The book Networks of Power: Electrification of Western Society

1880-1930 by Thomas Parker Hughes is a detailed account of why different electrical systems were chosen in different parts of the world (and initially in the USA).

Included in the book is a discussion of frequency. As another poster has pointed out, 50 Hz was indeed chosen by the German Industrialists who dominated the sale of electrical equipment at the turn of the century and the rest of Europe followed in lock step.

50 Hz has the advantage of being slightly more efficient for the transmission of power (less inductive reactance) considering a given set of transformers and transmission equipment.

In the USA, at the turn of the century when carbon lamps were still common (and frequencies were still not standardized), the lower wattage bulbs produced a noticeable flicker (as the filament cooled at

25, 32 or 50 Hz) and it was found that a 60 Hz system minimized or eliminated this. The lower frequencies, however, were better suited for motors, electric railways, etc. given the technology of the time. Many dual systems existed.

Incidentally, there were many "oddball" frequencies in use (other then

50 or 60 Hz), mostly in isolated US towns that had their own central station power plants in the early 1900's.

New York had sections of the city that offered only residential DC up through the twenties and thirties. Special DC appliances such as radios were sold exclusively for these districts.

In the US, Standardization of frequency was a consequence of having to interconnect all of these distant systems with much of the leadership and pioneering work done by Samuel Insull and the Public Service Company (later Commonwealth Edison) of Chicago.

Many transmission advances can also be attributed to scientists and engineers in Europe, where the first long distance DC transmission system was invented and where such critical devices such as the transformer were invented.

Beachcomber

The story I heard was that when it was time to decide on a frequency to use, Tesla thought of the requirements for a moment and came up with

60 Hz. At the time, the large motors and generators operated most efficiently at low frequencies, but low frequencies would cause light flickering. If the story is true, Tesla decided 60Hz was as slow as it could be to avoid flicker. Note that even today, there are some electric railroads that use 25 Hz power in the US, and I think 16 2/3 Hz is used for some railroads in Europe.

For a while, different frequencies were used. Niagara Falls generated 25 Hz (maybe still does on the Canadian side), and I've seen a turn of the last century generator that produced 40 Hz.

I was serious, I'm sure that is correct.

sQuick..

On Thu, 9 Mar 2006 17:01:33 -0000, "sQuick" Gave us:

Said "geo-magnetic properties" of soils vary from place to place to place all over the world, and that in much smaller chunks that one the size of our country.

What you have said makes NO sense at all, considering that the soils (there are none) in So Cal, and those back east differ by orders of MAGnitude.

I doubt it was a consideration at all regarding the entire country. It MAY have been a consideration in the locale where these things were being engineered.

On Thu, 09 Mar 2006 12:27:20 -0600, Bud-- Gave us:

Which ALSO has NOTHING to do with the "geo-magnetic properties of the soil".

But in heavy iron mining areas it is not uncommon to use 50 Hz or even

25 Hz to lower the impedance of distribution lines.

I think you will find this is done to prevent acid rain in the area.

sQuick..

But in iron mining areas the soils have a high iron concentration. Every thing turns red from the dust.

bud--

And why do you suppose 3600 rpm is chosen? To get 60hz? A circular argument, 60 hz because of 3600 and 3600 because of 60 hz.

Europeans find it easier to use 50 hz since their generators spin at 3000 RPM. Why do you suppose their generators run at 3000 RPM and ours at 3600 RPM??

daestrom

That is a question that really can't be clearly answered. Similar to asking why do they drive on the left side of the road in UK and the right side in the U.S.?

I put it down to a couple different individuals a hundred years ago making a WAG estimate of what should be used. As I said in another post those at Westinghouse decided to use 60 and those at AEG in Germany decided to use 50. Each had more or less a monopoly in their local market and it became the standard for their areas.

------- Now, that is as silly as the geomagnetic reasons offered by sQuick. :).

Windings and system design are no easier at 60Hz than at 50 Hz. Differences occur but aren't related to the number of degrees in a circle and not increasing or decreasing the effort of design and construction.

Also, The original generation at Niagara (Westinghouse/Tesla) was at 25Hz to add to the confusion - actually better for the desired motor speed ranges of the day. Some of this plant was still in use after WW2. Flicker was terrible.

--

Don Kelly @shawcross.ca remove the X to answer

On Fri, 10 Mar 2006 05:24:52 GMT, "Don Kelly" Gave us:

Not at all as silly. You HAVE to give me that. Now have a look at my logic. Far better than his.

Not true. I can divide up a 3600 rpm 60Hz rotor across 360 degrees in MY HEAD.

Whereas at 50 Hz and 3000 rpm,. the calculation of segmenting up a rotor for winding becomes a problem one doesn't or isn't able to do in one's head.

Sure there is a difference. The design cycle is a LOT faster when the engineer can flip the numbers off in his head like that. The 50Hz design REQUIRES a calculation tool, and more though, hence more time involved.

Which is why it is only still used in some light rail applications.

many thanks to you.this was a doubt for long time.now it is clear. thank you. shree