[Continued from SUPPLEMENT, No. 1172, page 18764.]




THE DEVELOPMENT OF THE CENTRAL STATION.

By SAMUEL INSULL.[1]

[Footnote 1: Before the Electrical Engineering Department of
Purdue University, Lafayette, Ind., May 17, 1898.]


The success of the low-tension system was followed by the introduction
of the alternating system, using high potential primaries with the
converters at each house, reducing, as a rule, from 1,000 down to
either 50 or 100 volts. I am not familiar with the early alternating
work, and had not at my disposal sufficient time in preparing my notes
to go at any length into an investigation of this branch of the
subject; nor do I think that any particular advantage could have been
served by my doing so, as it has become generally recognized that the
early alternating work with a house-to-house converter system, while
it undoubtedly helped central station development at the time, proved
very uneconomical in operation and expensive in investment, when the
cost of converters is added to the cost of distribution. The large
alternating stations in this country have so clearly demonstrated this
that their responsible managers have, within the last few years, done
everything possible, by the adoption of block converters and
three-wire secondary circuits, to bring their system as close as they
could in practice to the low-tension direct-current distribution