The Folsom Power
House and transformers. Folsom, California
(Notice the round port on the 2nd floor which allowed for the original
Stanley air-cooled transformers)
Folsom Power House was one of the earliest alternating current
power plants in the United States. In 1895 it opened and operated as
the longest transmission lines of any power plant in North America.
It produced power and sent it 22 miles to Sacramento. That was the longest
power transmission in the U.S. until that time. Experimental single-phase
alternating current power stations
were first built in US in the mid 1880s. Ten years later the work of
many engineers culminated into the work at the Folsom Power House,
the facility was the one of the first equipped with three phase 60 cycle
power, the same type of power we use today. To read more click on the
link to the California Parks website below. For more
photos see the lower part of this page.
powerhouse is open for free visitor tours Wednesday-Sunday, 12pm-4pm.
Group tours can be scheduled at (916)985-4843
this Power Generation Site:
features: First commercial 60 cycle 3-phase power system
(now our modern system), was the farthest commercial
power transmission until the next year (1896), when Niagara
Falls power was transmitted using a GE system to Buffalo from
the 1895 Westinghouse powerhouse.
Frequency: 60 cycle Three-Phase, Alternating Current Power Transmission Length: 22 miles at 11,000 volts using
#1 wire Power system built by: General Electric Notable Engineers:Elihu Thomson
(generators), William Stanley
(original transformers), Dr. Louis Bell (became chief
transmission engineer) Maximum Power Output: 3000 kW
of the Folsom Powerhouse see below.
the videos of the generators and transformers below:
and Turbine Areas: (9:24 min.)
and Power Transmission Lines: (4:30 min.)
Gear and Lower Power House: (7:37 min.)
General Electric Alternating Current Team in 1895:
Louis Bell: Designed the power transmission system.
Decker: Worked on early 3 phase generators for General Electric
Thomson: Worked on the first General Electric 3 phase AC generators
Stanley: Designed the earliest transformers
P. Steinmetz: Improved three phase power technology through
mathematics and design
1. POWER HOUSE CONTROLS
board built with Tennessee marble
ammeter is non-shunted, it takes the full load from bus bar.
generators were built in Schenectady, New York.
brush carrier, brush holder, feed spring (these were burned by an overload
just before closing the plant)
See more about this burned up generator in the end of the video above.
Winding bars and field coil splice Right: Four pole DC Excitor,
most likely shunt wound
Alternating current generator Type AP No 1376 Class 24 760 800 Form
Volts no load -- full load 830 Amperes 542 Speed 300 Patented Jan 13
1880 Oct 10 80 March 25 84 Apr 222 89 March 4 90 Marc 14 1892 Apr 4
82 Nov 14 1892 Patents applied for General Electric Co. Schenectady,
of North America's first commercial AC generators!
view of the generator room
of the motor genset -3 phase (this is the one in the next photo above
on the right) originally put in for the lower powerhouse to energize
the field coils and later on this provided standby DC power.
drawings for Elihu Thomson's three phase generator in 1894
of four main turbines, has gearing for the wheels, gears used to maintain
Originally in 1895 the plant was equipped with Stanley air cooled transformers
(aka air-blast transformers)
original transformers were replaced with Stanley oil filled transformers
ADDITION TO THE SECOND GENERATION OF TRANSFORMERS
These 11kv (oil filled) Westinghouse transformers were added in
1917 to permit increasing the 60kv output of upstairs Stanley transformers
by combining their 11kv and 60kv windings.
Transformers are locted outside. (left side of photo)(800v, 60k. &
Lower Powerhouse was built in 1897 to alleviate a late summer
shortage shortage of water. The water in the afterbay provided
a 26 foot head for another generator. The turbine was placed below
the high water line and coupled to a generator sitting above it
with an unique 2200 foot rope drive. Generator #4 was temporarily
moved down to the site until replaced in 1900. Photo right: generator
with the rope drive
A new generation of AC generator 1900:
field slip ring (the field was on the rotor) wires carry DC power from
the rings to the field coils
Field Coils on the left, stator on the right. 3 phase Right:
Shooting the interview with Bill Henning, PH Docent see the videos at
the top of this page.
Power Houses (upper and lower) as seen from across the River
is the Folsom Powerhouse no longer used?
Powerhouse was no longer needed when it was decided to construct a larger
dam in 1952. In the photo below one can see the old stone dam which
was blown out during construction of the new dam in the background.
is created by the modern hydroelectric dam that replaced the historic
Folsom Power House. This lake is formed by the American River and extends
into the foothills of the Sierra Nevada mountains in central California.
The river is fed by an enormous watershed that peaks at the mountains
just west of Lake Tahoe.
top of the watershed is on the other side of the mountains here in the
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