~e; 50/60 Hz frequency standards

From brian carroll <human@electronetwork.org>
Date Mon, 15 Mar 2004 11:32:02 -0600

// could not find anything specific online except for
// 'metering standards' pegging decisions at 1910.
// so went to a book in the cardboard box archives...
// The book focuses on .DE, .UK, and .US systems:

quotes from: Thomas P. Hughes' Networks of Power
Electrification in Western Society, 1880-1930
  ISBN: 0-8018-4614-5 (paperback) pp. 127-129

	"... Early direct-current stations with franchises covering small 
central-city districts merged. Polyphase transmission allowed for 
large-area supply, so the alternating-current utilities supplying the 
suburbs merged into new organizations with the intention of gaining the 
entire urban market. The series of mergers that occurred in America and 
Germany, and to a lesser extent in Britain, are documented in numerous 
utility histories. (43)

	"Agreement about technical standards also contributed to the 
resolution of "the battle of the systems" and the establishment of the 
polyphase, or universal, system. During the period from 1887 to 1892, 
when the struggle was intense, utilities and manufacturers chose 
different frequencies. Depending on the particular character of supply 
and load, different frequencies had distinct advantages. Therefore a 
general agreement about frequency did not come through the 
establishment of one frequency's obvious technical superiority over the 
others; rather, a spirit of flexibility and compromise among the 
various utility interests, and especially among the manufacturers, was 
primarily responsible for the agreement. Other important factors were 
precedent and successful practice-- e.g. Edison's introduction of 110 
and 220 volts for power distribution in the United States.

	"These historical circumstances and events ought to be remembered 
because later generations often assume the standards necessarily 
represent the clear technical superiority of one system over another.

	"During the early years of alternating and polyphase currents, 
133-1/3, 125, 83-1/3, 66-2/3, 60, 50, 40, 30, and 25 cycles were used. 
(44: Benjamin G. Lamme, "The Technical Story of the Frequencies," 
~IEEE~Transactions 37 (1918): 60.)  Designers and engineers chose the 
frequency that was optimum for the particular set of characteristics 
created by the coupling of incandescent lamps, transformers, arc 
lighting, induction motors, synchronous converters, or other apparatus. 
Because design of this equipment was changing rapidly, however, an 
already complex situation became more complicated. In America, the 
engineering staff of the Westinghouse Company played a leading role in 
dispelling the disorder; they attempted to rationalize production by 
standardizing frequency. Freedom to decide on a standard frequency was 
constrained by the fact that a large number of Westinghouse-designed 
central stations {{powerplants}} were supplying incandescent lamps with 
60 cycles, but the die was not cast. The Westinghouse designers took 
into account the spread of the slower-rpm, directly coupled (rather 
than belt-driven) generators that had first been introduced in Europe. 
The slower generator, or alternator, was less complex when designed for 
lower frequencies such as 60 cycles because fewer field poles were 
needed for them than for higher frequencies such as 133-1/3 cycles. Yet 
other designers advocated a high frequency because it reduced 
incandescent-lamp flickering. The development of a synchronous 
convertor that operated well at 60 cycles encouraged supporters of this 
frequency because utilities could couple existing single-phase systems, 
direct-current systems, and the polyphase extensions  and transmission 
networks. This ability to couple the old with the new lessened support 
for 40 cycles, a frequency that had been advocated by some because of 
its suitability for motors and transmission. Design of unprecedentedly 
large equipment for a Niagara Falls installation also shaped the 
ultimate decision. George Forbes, chief consulting engineer for the 
Niagara site, proposed 16-2/3 cycles, but Westinghouse engineers then 
wanted 33-1/2 cycles. The relatively low frequencies were well suited 
for power transmission. The midpoint of this particular difference was 
25 cycles. By about 1900, Westinghouse, the other manufacturers, and 
the utilities were settling for two standards: 25 cycles for 
transmission and for large motors, and 60 cycles for the more 
general-purpose systems. Introduction of the high-speed turbine as 
prime mover accelerated the trend towards 60 cycles because generators 
with fewer {{magnetic}} poles could be used than with the slow-moving, 
reciprocating steam engines. A Westinghouse engineer who took part in 
the technical activity surrounding the frequency question took pains to 
point out that the struggle to set standards was not a competition 
between manufacturing interests, as was the case with many issues 
during "the battle of the systems"; rather, it was an effort by 
technical persons to find a means to reinforce an all-embracing, 
general system of supply. The battle was indeed over. (45)

	"In Germany the decision on a standard frequency may have been less 
difficult to reach because AEG... encouraged the use of the 
slower-speed, directly coupled generators from which high frequencies, 
such as 133-1/3 cycles, were difficult to obtain and because 
synchronous convertors, for which low frequencies, such as 25 cycles, 
were most suitable, had not been widely adopted. The outcome in Germany 
was a standard of 50 cycles.

	"The Situation in Britain remained disorderly. The tendency before 
World War I was toward variation, not standardization. London led the 
trend; by 1914, at least ten different frequencies and a bewildering 
assortment of voltages were in use in that city. Reasons for the 
variety included the absence of oligopoly in the electrical 
manufacturing industry and the prestige and influence of the consulting 
engineers. (46)  One British manufacturer complained that his 
competitors, confident that individualism, not business opportunism, 
characterized professional competence, carried individualism in in the 
design of equipment to an extreme. Having a highly particularized 
design seemed to show that the manufacturer and his designers were 
"engaged in a superior branch of applied science, not in an industry, 
still less in a trade." (47)  R.E.B. Crompton, a small manufacturer and 
leading consulting engineer, lamented that the consulting engineers 
with their design fads; the municipal governments that employed them 
and took pride in having their own ideas about how "switchboards and 
other plant . . . should be done";  and the small manufacturers, who 
were content to have a small order for individual components, retarded 
not only the move for standardization but the overall growth of the 
British electrical supply industry. (48) An exception to this rule was 
the system of electric supply on the northeastern coast of England, 
where Charles H. Merz, consulting engineer, was the primary influence 
on the design of a regional system (see pp. 443-50 below). Merz 
standardized 40 cycles in the region centered around Newcastle upon 
Tyne. His reasoning was logical and systematic, for he took into 
account the characteristics of the region. His rationality proved 
expensive, however, when after World War I his system had to be 
integrated at great cost into an all-British one in which 50 cycles was 
the standard frequency. (49)"
  pp. 127-129

	...(further on .UK)    "The year 1926 and establishment of the Grid 
brought a dramatic change in the orientation of NESCO and Merz & 
McLellen, for they were forced to rethink their plans for regional 
electrification in the context of a national network. The most 
immediate and difficult problem for NESCO was the change in frequency. 
It was an especially vexing problem {{see above}}... After 1926, 
ironically, the system's 40-cycle frequency was defined as nonstandard. 
The earlier process of integration by means of high-voltage 
transmission, centralization of control, and standardization had taken 
more than a decade, but with the coming of the Grid, this remarkable 
achievement became a 1,400 mile inconsistency.

	"The Central Electricity Board decided on the uniform three-phase 
50-cycle standard instead of NESCO's 40 cycles because 50 cycles was 
the European standard (except in Italy); because most of the existing 
British polyphase power plants outside NESCO operated at 50 cycles; and 
because British manufacturers wanted a market outside England for the 
equipment they would design and supply in quantity for the Grid. (100) 
The decision entailed serious consequences, for it involved conversion 
of hundreds of turbogenerators, hundreds of thousands of motors, and 
almost half a million consumers from other frequencies." {{circa 1926}}
pp. 458-59

(and, for anyone interested in an exploding transformer
.mov see:  )

  the electromagnetic internetwork-list
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