Hydroelectric Plant
The first electrical generation facility in Fall Creek gorge was built in the early 1880's. That plant was powered by water from a dam just above the present plant, with a water wheel just above the present plant with a cable to a generator located near the Foundry. In 1904, the present plant was built. Construction was preceded by replacing Triphammer Dam slightly west of it original location beginning in 1896. Water is supplied to the plant from Beebe Lake by a five-foot diameter underground penstock, 1700 feet long. The existing intake dates back to 1953 and was upgraded in 1981. It is scheduled to be updated in 2017 to increase production.
The original plant capacity was 300 kW with 2 Pelton Wheel turbines and two 30kW DC exciters. This was increased in 1913 by adding a 360 kW Francis turbine. The facility was overhauled in 1935 after being completely flooded. In 1957, No. 2 generator was replaced with a 175 kW unit. The plant capacity then stood at 850 kW @2,400 volts. In this configuration, the plant last operated in 1970. It was vandalized in 1972.
In 1981, the plant was completely renovated and all the original machinery removed. Two Ossberger crossflow turbines were installed with a total rated capacity of 1,780 kW. The plant, however, is limited to about 1,200 kW output because of the size of the penstock. Plant upgrades since 2007 include new PLC controls, new powerhouse roof and stairs to the powerhouse, and complete factory overhaul of both Ossberger turbines.
This hydroelectric plant is "run of river", which means that no water is stored. At all times, 10 cfs must continue to pass over the dam. The average annual production for this plant is 4.5M kWh to 5.5M kWh.
Unit #1
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Unit #2
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Turbine Manufacturer
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Ossberger
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Ossberger
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Type, Model
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Crossflow G8069/17g (2 cell)
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Crossflow G1078/20g (2 cell)
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Rated Capacity
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712 kW (conservative rating)
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997 kW (conservative rating)
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Net Head
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115 feet
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115 feet
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Discharge Speed
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88.3 cfs
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123.5 cfs
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Increaser Manufacturer
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Flender
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Flender
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Model
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Sen 360
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Sen 450
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Generator Manufacturer
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Reliance
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Reliance
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Type
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Induction motor
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Induction motor
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Rated Capacity
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750 kW
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1,030 kW
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Voltage
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2,400 V
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2,400 V
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