Really, in those years, the main use of electricity was lightning and either frequency perfectly fulfilled the requirements of quality, with lower frequencies the lamps would began to produce an annoying flashing effect.
1890 - 1925
This a period in the one appears an element that will annoy the relative tranquility of manufacturers, the induction motor.
The motors that were used for the development of mechanical power that moved the machines tools were couple directly, motor - machine toll, of the the machine worked at 80 rpm, it will required a 200 poles motor working ar 133 +1/3 Hz. This problem, the elevated pole number, wouldn't appear in Europe since there they used 40 Hz, therefore they required only 60 poles machines.
In 1890, AEG and Oerlikon used 40 Hz for their 175 km three-phase electrical line, from Frankfurt (receptors) to Laufen (production) using an alternator of 50 V phase tension, 32 poles with a spin speed of 150 rpm, that gives 40 Hz frequency. The transmission was made transforming in the origin from 50 to 8.500 V and in Frankfurt it was reduce to 65 V. Later they realize the stroboscopic problems, due the low frequency applied to the lamps and by 1891 they chose to used 50 Hz, that solve both problems. Generators design to feed the motors and lightning systems.
In 1890, the engineers form Westinghouse realize that working with frequencies above 130 Hz was preventing their induction motor development, to many poles in the machines stator. Analyzing the problem, came with the conclusion that 7.200 cicles (p*n), and therefore 60 Hz, was the optimum value for their motors and the coupling of the machines that were manufactured back them.
Steinmetz just before started working at Thomson-Houston Company determined the resonance problems, with the material that Hartford Electric adquied, was due the harmonics of the 125 Hz signal used to supply the energy. The way to solve this was reducing to 62,5 Hz. General Electric kept using 50 Hz that used its European partner AEG. In 1894, General Electric, realize that they where loosing sales in the AC market and drastically change to 60 Hz.
Is wasn't unanimity respect the 60 Hz, one of the biggest projects of the generation in the times, The Niagara Falls project, in 1892, to give electrical energy to Chicago chose a two-phase alternator of 12 poles, rotating at 250 rpm, that gives 25 Hz, Westinghouse was the company that develop the project. Like ways other manufacturers in those times build alternators of 8.000 cicles - 66 +2/3 Hz.
1925 - Actuality
Even when it seems like since 1921 every electrical system in EE.UU used 60 Hz, it wasn't like that. The transformation process to the standard frequency last until 1948. For example the Mili Creek Installations were not modified until the end of WWII.
In England it was even worse since the Electric Light Act came up, where is was stated that every electrical material that were manufacture had to be able to be used for any person or compay, this prevent the transformer develop by Gibbs and Gaulard to be used in England (this was one of the reasons of their technological delay) this was different in EE.UU or Germany.
A extremely peculiar case is Japan. The Yokohama department sent to EE.UU. engineers so they can study the different technologies about the electricity in the moment, 1889. When they came back to Japan, they were convince of the pros of the "high frequency" and bought and installed an alternator from Stanley-Kelly-Chesney (SKC) that worked at 133 + 1/3 Hz, in Keage Canal. In 1895 sold an alternator of 50 Hz to a company in Tokyo.
Lets Remember that Stanley of SKC then change to General Electric, and was then that determined that 133 +1/3 was to high frequency for AC electrical motor, and changed the alternator production so they generated AC at 60 Hz. When a company of Osaka bought an alternator to AGE, this one manufactured them to generated at 60 Hz and there the frequency division in Japan began to the momment: East 50 Hz and West 60 Hz.
Summary
Truly, the determination of the most convenient frequency came from the necessity (like all technology existing) of over come the tech problems that were presenting while the electrical energy spread around the world.
So, in the first years the electrical energy was used almost exclusively for public lightning, hotels, banks and houses of wealthy people and to avoid the stroboscopic effects high frequencies were used.
When the electrical energy got into the fabrication process and the energy consume was designated no only to lightning, but also to power in motors the frequency was reduce to the the actual values.
The reason WHY 50 Hz in Europe and 60 HZ in EE.UU, came only and excusably determined for the position of preponderance of AEG in Europe and GE in EE.UU, whose engineers at some point chose chose on of the actual frecuencies
"The winner sets and tells the history"
Source: Articulo “El origen de los 50-60 Hz en la transmisión de la energía eléctrica”. Wrote by Eduardo Aznar Colino y Joaquín Royo García, and publish in Técnica Industrial 242 (Septiembre de 2001). Vía afinidadelectrica.com.ar
Translated by: Eg. Aaron Paradas
