208 POWER DISTRIBUTION FOR ELECTRIC RAILROADS.
We may now lay out the system as shown in Fig. 112
and plan the stations and feeders. We have two stations,
E and F, of equal size, each supplying half the whole line,
A B. 'The station, E, however, serves a line five miles in
one direction (E A) and ten miles in the other (E G) to
G, the center of the line. The station, F, feeds 74 miles
each way. Fach of these stations must be able to furnish
a maximum current of about 600 amperes and an average
output ot about half this. ‘The voltage should be as great
as the standard generators can conveniently give, say, 600
volts as a maximum.
If we are, as in the previous discussion, to allow fif-
teen per cent loss at full load, ten per cent in the feeders
and five per cent in the trolley wire, the generators may
f* 5-ms >i«— =t e s le—— e >
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50000 c. m. 250000 c. muilitii i
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500000 ¢. m., §00000 c. m.
Street Ry.Journal
HIG: 112,
well be given an overcompounding for ten per cent, thus
taking care of the loss in the feeders. .
Fach station should be equipped in duplicate, partially
at least. The maximum continued output at any time we
have assumed at 360 k. w., 600 amperes at 600 volts. ‘The
average output is about 180 k. w. and, save at special
times, the maximum output would be considerably less
than that noted above. If at each station were installed
two generators, of 225 to 250 k. w. output apiece, one of
these would handle the whole load of the station during a
considerable part of the day, and the second could be
thrown in on the heavy hours or all day on special occa-
sions. In case of accident to a dynamo or an engine the
remaining one could keep up the service without serious
interference with traffic, particularly if the feeders were
arranged judiciously.
As regards the arrangement of these units it is rather
an open question between direct coupling and direct belt-
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