The record-union., 1896-05-22
ELECTRICAL TRANSMISSION.
Technical Description Of the Sacramento
System.
Interest Awakened in It Among the
Business Men of the
World.

gineering News" will be read with IN
terest in connection with the report IN
yesterdays "Record-Unio OF the ex-
cursion of business men to Folsom on
Wednesday,:
The completion of the power trans
mission scheme between Folsom and
Sacramento, Cal, is the conclusion OF
vast enterprise, undertaken in doubt and
terminated in a success which has DEM
OnStrated not only the tremendous re-
sources of power in the State OF Cali
fornia, but also the commercial feaSl-
bility of electrical transmission over
long distances sketch of the pro-
gress of the work including view of
the dam at Folsom, was given in our
issue of April II, 1895. In what fol-
lows we give an account of the electric
plant in somewhat greater detail
The hydraulic apparatus, manufac-
tured by S. Morgan Smith of York, Pa,
consists of four pairs of 30-inch wheels
Of the Mccormick horizontal shaft tur-
bine type, each pair of 1,260 HIP. ca
pacity at 300 revolutions operating
under a head of 30 ft. The steel pen
stocks are s #. in diameter, and each
wheel has two draft tubes. The gov
ernorS are of the Faesch-Picard type,
and these are assisted by heavy fly
wheels fitted to the water wheel shafts.
The hydraulic plant also includes two
special horizontal wheels for the eX-
citers.
The power house is two-Story brick
building. The water wheels are placed
in the open air between the forebay and
the wall of the structure, through which
the turbine shafts pass. To each shaft
Is coupled a 150-K-W. 0,000-HP) Cen
eral Electric three-phase generator, the
largest of their type yet constructed.
Each is a 24-pOle machine delivering
current at 60 cycles, 500 volts and run
ming at 300 revs. per min. The exciters
are 4-pole, 500-volt, 80 XIV genera
tors, either one of which is of sufficient
capacity to excite the fields of all four
generators. From the generators the
current passes to the generator switch
board, and thence to nine step-up trans
formers, each of 200-K-W capacity in
the upper story of the power house The
transformers are cooled by an air blast
from blowers driven by induction
motors. In these transformers the
pressure is raised from 800 to II 900
volts, and from them the current passes
to the high-tension transmission line.
The SWltchboardS are of Tennessee
marble, and are so arranged that the
generators may be run in parallel or on
separate lines as may be desired The
generator switchboard carries the ne
ceSSary switches, instruments and other
apparatus for synchronising the genera
tors. The boards in the transformer
room carry switches for the high and
low tension sides of the transformers
and switches and current indicators for
the transmission lines
The pole line is double throughout.
and follows the highway from Folsom
10 sacramento, a distance of twenty
TOUR miles Each pole carries two cross
arms for two circuits, each circuit con-
sisting Of three bare copper wires sup
ported on double petticoated porcelain
insulators, especially designed and
made for this installation at the por-
celain factory of the General Electric
Company at Schenectady Each insu-
lator before shipment was exposed to
a test of not less than 25,000 volts alter
hating. Each circuit can carry the
output of one dynamo, and any dynamo
can be thrown on any line. The line
loss is calculated at 7.5 per cent when
transmitting 1900 Fl. p.
The telephone line is carried on the
same poles as the transmission line
and connects the power house with the
sub-Station in Sacramento. The trans
mission lines being spiraled every mile
and the telephone wire transpOsed
every fifth pole, no induction is no.
tieeable on the telephone circuits. and
conversation is not in any way inter
fered with.
10 l. s-%o t. g
ry brick building on the corner of Sixth
and II streets, Sacramento having the
transformers on the second floor and
the dynamo-room on the ground floor.
In the transformer-room the high-ten-
sion switchboards receive the termi-
nails of the 10.000-volt lines and oper-
ate the different combinations of the
step-down transformers. These trans
formers, twenty-one in number, fifteen
of 125 XIV, and six of 40 XIV capac-
ity, vary in size, according to the duty
required of them, the secon diaries deliv-
ering current at 125, 800 and 1000
volts. They are also ventilated by
blowers.
The transformers are connected to
high and low-tension switches on the
boards, and from these the current
passes to the distributing boards for
the synchronous motors, power cir
cults and incandescent lighting.
In the main or dynamo-room of the
sub-station line shaft runs the entire
length To this are directly coupled,
through friction clutches, three syn
chronous motors. each of 2o0 XIV ca
pacity, wound for a potential of 800
volts and run at a speed of 400 revolu-
tons To the line shaft are helted one
200 XIV. and one 90 XIV. multipolar
G. E railway generators and two 100
XIV Edison bipolar machines, all of
500 volts. and three 100-light and two
15-Iight Brush arc machines. In this
room are also the switchboards for con-
trolling the synchronous motors, the
railway generators and circuits and the
arc dynamos-
For the operation of the synchronous
motors 7J0 XIV. of transformer ca
pacity is utilized, the balance being
used for low and high-tension distri-
button. The low tension current IS dis
tributed by a three-phase, four-wire
system, combining the three-phase and
Edison three wire SYSTEM. G., three
wires for the three-phaSe current and
fourth or neutral wire. 1ncandescent
lights are connected between the neu-
trail and any one of the three other
wires, while motors are connected to
the three-phase wires, giving at the
mains l15 volts for lamps and 200 volts
for motors. The feeders for this extern
sive system pass from the sub-station
through a distributing switchboard,
which carries potential regulators Tor
maintaining constant pressure at the
mains. Additional circuits run from