Publication: Electrical World
New York, NY, United States
The Enlargement of the Niagara-Buffalo Transmission Line.
The increased demand for Niagara Falls power in Buffalo has necessitated the installation of more copper on the transmission line carrying power from the Niagara Falls Power Company's plant, at Niagara, to the points of distribution in Buffalo.
On the pole line which was described in THE ELECTRICAL WORLD of June 19, 1897, there have been placed three new wires of 350,000 circular mils each. All six wires are placed on a six-pin cross arm, the two circuits being symmetrically placed on opposite sides of the pole. The wire is transposed five times between terminals, the transposition being effected by the aid of a second cross arm and a simple spiralling. The wire is supported on triple petticoat type "C" Imperial insulators, the same as those which have given perfect satisfaction on the original wires. The wire was made by the American Electrical Works, and is built up of nineteen strands, the weight per mile being 5600 pounds. The new wire was raised with-out turning off the current from the old line, which is operated at 11,000 volts. Special care was necessary when the woodwork was wet and rollers were placed on the cross arms, so that in hauling the wire over the arms there would be no tendency to disturb the line already in place.
The underground section within the city of Buffalo has been laid with cable made by the General Electric Company. The insulation is of the best quality of rubber compound, 9-32 of an inch in thickness, and the three lines instead of being in separate lead sheathings, are laid up together and covered with one lead sheath, the outside diameter of the whole being 2 5/8 inches. This is then drawn into 3-inch ducts of tile made by the H. B. Camp Company. This avoids the inductive effect and consequent loss of energy in the metallic sheathing of the single-covered cables, but increases somewhat the difficulty of making proper joints. The cable now in use has given no trouble at all on the straight work, but it has been found some-what difficult to make all the joints sufficiently perfect and dry to prevent an occasional breakdown. The new line was erected by the J. G. White Company, who built the original line.
The three transformers used to step-up the two-phase current, as supplied by the generators at 2200 volts to three-phase current at 11,000 volts, will be augmented by seven new transformers of the same size, made by the General Electric Company. Each of the ten transformers has a capacity of 1250 horse-power, giving a total step-up transforming capacity of 12,500 horse-power. These trans-formers are of the air-blast type and will stand in rows of four upon the air-pressure chamber whence the air is forced through the ventilating spaces in the transformers. It is intended to eventually raise the line pressure to 22,000 volts in place of the present 11,000. At the Buffalo end of the line new step-down transformers will be in-stalled by the Cataract Power and Conduit Company to reduce the pressure to various voltages for distribution over the city network for motor uses. Several step-down transformers will also be placed in the station of the Buffalo General Electric Company to supply current to rotary converters, from which direct current will be taken for lighting and small motor service.
The Buffalo Railway Company is also increasing its step-down transformer and rotary-converter capacity in the Niagara power house. Three additional step-down voltage transformers are being installed in the transformer house between the station and the canal. These will be similar to the three already in use, each of 275-kw capacity, and stepping the current down from 10,500 volts to 375 volts three phase, for delivery to the alternating current side of the rotaries. In addition to- the two 500-hp rotary converters already in operation there will be added two others of smaller capacity and construction, made by the General Electric Company. These will bring the total converter capacity in the station up to 2000 horse-power.
For further distribution in the city of Buffalo 45,000 feet of paper insulated cable has been supplied by the National Conduit and Cable Company. This cable is three-conductor, lead covered, with insulation seven thirty-seconds of an inch in thickness. Before leaving the factory it was all tested to a pressure of 25,000 volts alternating.