Origin of 60 Hz Frequency for Electric Power

[SlideRuleEra]

This may have been discussed before, but I came across this short article that offers an understandable reason... the capabilities of the the earliest AC equipment combined with the process of elimination of frequencies that had drawbacks.

http://www.antiquewireless.org/otb/60cycles.htm

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[waross]

I was under the impression that after seeing 25 Hz in action, the British decided that 50 would be much better,
When the shortcomings of 25 Hz versus 50 became apparent, the Yanks went one better by going up to 60 so as to avoid using and appearing to copy the british 50 Hz system.
Would anyone do that?
Well. Robertson head screws are much better performers than Phillips head screws. It took about 50 years before Robertsons were used in the US, possibly because the patent was not US.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[msquared48]

Now I know why I'm not an electrical...

Mike McCann
MMC Engineering

 

[MikeHalloran]

My grandfather's business card said "Superintendent of Phase Change". I guess 'phase' was shorter than 'frequency'. He was in charge of the transition from 25Hz _and_ 50Hz to 60Hz for a Northeast US utility.

He said they picked 60Hz because lamps flickered noticeably on 50Hz. I'm guessing maybe they also did it so they wouldn't have to tell only half of their customers that they needed a houseful of new clock motors.



Mike Halloran
Pembroke Pines, FL, USA

 

[SomptingGuy]

Interesting.

Also interesting that 60Hz seems to be married with 120V, whereas most 50Hz supplies are at 240V.

http://en.wikipedia.org/wiki/File:WorldMap_Voltage&Frequency.png

- Steve

 

[ScottyUK]

Except in Europe 240V is now 230V, and 220V is also 230V because Brussels says it is so. In the UK my 230V supply still reads 243V tonight. Ho-hum.


----------------------------------

If we learn from our mistakes I'm getting a great education!

 

[IRstuff]

Not sure if there's that much difference in the US; while it's ostensibly 120V, I've seen it referred as 110 and 115.

TTFN

FAQ731-376

 

[waross]

110V, 115V, you can sometimes guess the age of the speaker, or the speakers mentor by the number used for voltage.
The standard is 120 Volts. It was not always so.
Many years ago there was a lack of standardization in voltages in North America.
I have seen antique appliances rated at 105 Volts, 100 Volts and one at less than 100 volts. (95V or 97V)
Utilities across North America agreed that the voltages should be standardized and that a higher voltage was desirable.
They decided to increase the voltage to 150 Volts at the rate of 1/2 volt per year as I remember. The rate may have been even less. This was based on the expected lifetime of appliances and of the distribution transformers in use at the time.
The standard voltage for appliances was 110 Volts for a time. Then 112V was standard. The next step was 115V, followed by 117V and finally 120 Volts. At this time the plan was re-evaluated and two new factors were considered.
The normal life span of transformers and appliances had increased dramatically and 120 Volts was working well. The voltage was standardized at 120 Volts.
Note that the electrical codes in North America may have been written in anticipation of the expected 150 Volt standard as there are rules that apply to circuits above and below 150 Vots to ground.
I have been looking for the source of this information for years. If anyone can verify this information I will be grateful.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[SlideRuleEra]

waross - Your information fills in the gaps in a version of this story that one of my Electrical Engineering professors told us in the late 1960's. He was well over 70, at that time, and had worked in the 1920's with General Electric in Schenectady, NY, on power systems and later in the development of radio broadcasting.

His story went like this:
In the early days of AC power a (USA) national convention was held to develop standards. One consensus reached was that 200 volts (AC) was the maximum that could be safely handled in residential use. Even at that time house wiring had provisions for using both legs of the nominal 200 volt circuit (100 volts each).

Since generating voltage control had not been perfected, it was agreed that a plus or minus tolerance of 10% would be acceptable (180 volts to 220 volts, or 90 volts to 110 volts for each leg).

As time went by, voltage control was greatly improved so electric utilities took advantage of the efficiency gained by targeting the top to the tolerance range (220 volts).

Our professor admitted that he did not know why voltage kept creeping higher - that is where your explanation fits in very nicely.

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[gmax137]

Just today I was reading (in a book about the Brit "Ultra" codebreakers during WWII) that the standard in Italy during the war, anyway, was 45 hz (causing problems for the radio operators).