Publication: American Electrician
New York, NY, United States
THE OGDEN (UTAH) POWER TRANSMISSION.
The power plant of the Pioneer Electric Company, of Ogden, Utah, one of the largest works of the kind yet undertaken, has in part been completed. The complete plan contemplates the utilization of the waters of the Ogden River water shed, the central features being a storage reservoir, of 2000 acres and a capacity of nearly 15,000,000 gals.; a pipe conduit, 6 ft. in diameter internally; a power house and water-wheels and electric generators, transmission lines and substations for distributing the power to different points; and an extended system of irrigation lines.
The main conduit, has, as stated above, an internal diameter of 6 ft., and a total length of 31,600 ft., of which 27,000 ft. are of wooden stave and 4600 ft. riveted steel pipe The line passes through eight tunnels, the longest being 667 ft., and over steel bridges of a total length of 560 ft., besides a timber trestle.
The total effective head at the power house is 446 ft. The water is delivered into two receivers, buried in the ground, one on either side of the power house (Fig. 1). The two water-wheels are 59 ins. in diameter, and have each forty-five bronze brackets cast into one solid piece; fourteen of these, when the nozzle parts are all open, receive the water at the same instant. Each wheel has a capacity of 1200 HP at 300 r. p. m.
The generators used in this plant are of the General Electric Company's three-phase type, with twenty-four poles and at 300 r. p. m., have an output of 750 KW at 2300 volts and a frequency of 60 cycles per second. The factory tests show that the variation in volts will be less than 5 percent, with a constant speed, should the full non-inductive load be thrown off or on.
The cable connecting each generator to its respective panel on the generator switch-board is a three-wire concentric 250,000 CM lead-covered cable, and the exciting wires are a two-wire concentric No. 4 B. & S. lead-covered cable.
The exciters used on this plant are G. E. six-pole, 500 volt machines, and will give 100 KW at 550 r. p. m. Each of these machines is ample for the entire exciting current that will be needed for the ten 750-KW alternators to be put in, and they are each direct-connected to a 135-HP Knight water wheel, similar to the 1200-HP water-wheels previously described. These exciter water-wheels are cross-connected to each receiver, so that either exciter can be operated from either receiver.
The generator switch-board consists of seven marble panels; five for the alternators, one for the exciter and one for the instrument panel.
From the generator switch-board the current is carried to the distributing board by copper bars, of which there are two sets of three, connecting the two sets of bus-bars on the generator board with the two sets of bus-bars on the primary panels of the distributing boards.
Back of this distributing switch-board are nine 250-KW air-blast step-up transformers, the lightning arresters, and the two blowers for cooling the transformers.
Back of the distributing switch-board and on a raised platform are placed the step-up transformers. These transformers raise the potential of the current from 2300 to 16,100 volts, at which pressure it passes to the long-distance transmission lines. The transformers are connected up in sets of three, the delta connection being used on both sides. At each end of the building in the gallery are placed the