Publication: The Electrical Engineer
New York, NY, United States
LONG DISTANCE POWER TRANSHI5SI0N AT LOWELL, MICH.
BY J. B. W.
ONE of the most typical and the longest electric transmission plants east of the Mississippi River has recently been installed at Lowell, Mich., by the Lowell Water and Light Company. The power house Is situated about one mile east of the town upon the Flat River, a tributary of the Grand. On the east side of the river is a large waste weir, which is used in time of high water. The power house, a substantial brick building, is located upon the west bank.
In the basement of the building are three vertical turbines of 100 horse-power capacity each, two of them being Leffel, and one a new American special. These wheels furnish power for driving one 200 kilowatt "S. K. C." alternating current generator. The pumping machinery which supplies water for the village of Lowell is also located here. The wheels are so arranged that any one may be connected or disconnected to the machine line shaft by means of clutches, thus making it possible to throw any wheel in or out without shutting down the plant. The generator is belted to this line shaft and supplies current at 1,000 volts. The town of Lowell is supplied at this voltage. Step-up transformers raise the current from 1,000 to 10,000 volts, and at this high potential supply the transmission line upon which It Is carried to Grand Rapids, eighteen miles away; there it is reduced by means of step-down transformers to 2,000 volts and distributed for light and power indiscriminately. Eight thousand alternations are used in this work, and the motors of the "S. K. C." type with condensers are used exclusively for power.
The marble switchboard in the Lowell station is perfect in its adaptation and equipped with the best apparatus obtainable for high voltage work. Two double-pole switches and two "S. K. C." circuit breakers control the Grand Rapids line, while the Lowell circuit is similarly controlled. The generator is furnished with regulator heads by which the voltage of either phase may be raised or lowered independently of the other, thus making it possible to throw the load of the Lowell circuit upon either phase, and yet maintain a perfect balance of voltage at Grand Rapids, over eighteen miles away.
The pole line is of the most modern construction, and very substantial, consisting of 30-foot poles, with not less than six-inch tops, set 100 feet apart. The four No. 6 wires are carried upon two cross-arms, and are so arranged as to make a square having 18 inch sides, the diagonal wires of which form the circuits for each phase of the generator. They are supported upon the Locke triple petticoat porcelain insulators, which give very perfect insulation, the leakage being extremely small, even with a pressure of 12,000 volts upon the lines. The circuits are protected from lightning discharges by stringing a barbed-iron wire over the tops of the poles, which wire is grounded at every other pole. For indicating grounds upon the high voltage lines static ground detectors are used.
The Stanley Electric Manufacturing Company, and the Lowell Water and Light Company, have in this installation practically demonstrated that power can be carried long distances at high voltages through a thickly settled region and distributed for an indiscrimate use of arc, incandescent lights and power with perfect success, and that by using these high voltages the losses in the lines can within a commercial basis be reduced to less than the average losses in the distributing circuit of low tension direct current central stations in large cities.
The officers of the company are O. C. McDonald, president; Charles A. Church, secretary and treasurer; L. W. Kutsch, superintendent. The pole line was constructed under the supervision of Mr. M. M. Wood, of Chicago, and the installation of the electrical equipment was made by W. B. Jackson, one of the engineers of the Stanley Electric Manufacturing Company.