. The Street railway journal . bles. In supporting thesefeeders, No. 3 Locke insulators were used. Before being in-stalled the insulators were given a break-down test of 30,000volts, the company having installed in the power house for in-sulator testing and other high-voltage cable tests a 50-kw test-ing transformer capable of variations of voltage up to 50,000volts. Between sub-station No. 3, in the western portion of the cityand the power station the high-tension wires are carried in anunderground circuit. The conduit system, which was con-structed by the G. M. Gest Company, has double manho
. The Street railway journal . bles. In supporting thesefeeders, No. 3 Locke insulators were used. Before being in-stalled the insulators were given a break-down test of 30,000volts, the company having installed in the power house for in-sulator testing and other high-voltage cable tests a 50-kw test-ing transformer capable of variations of voltage up to 50,000volts. Between sub-station No. 3, in the western portion of the cityand the power station the high-tension wires are carried in anunderground circuit. The conduit system, which was con-structed by the G. M. Gest Company, has double manholes, one side for high-tension and the other side for low-tension 550-volt d. c. cables, separated from each other by a 6-in. wall ofconcrete. The conduit system was constructed with a muchgreater capacity of ducts than is at present demanded. Onleaving the station there are six a. c. ducts, only two of whichare occupied. There are also thirty-five d. c. ducts, which atpresent contain two positive cables and four ground return. FIG. 3.—OVERLOAD RELAYS AND HIGH-TENSION OIL SWITCHES cables of 1,000,000 circ. mil capacity. It is the intention, how-ever, to place all of the d. c. feeders leaving the station under-ground, and for this reason number of ducts wereinstalled. The two a. c. cables in the conduit go to the No. 3sub-station at Twenty-Eighth and Walnut Streets. Each a. contains three No. 2 copper conductors. Paper insula-tion 5-16 in. thick surrounds each conductor, and jute fills thespace between the wires. Paper insulation of the same thick-ness as that around each conductor covers the jute. The wholecable is enclosed in a lead sheath 9-64 in. in thickness. The
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectstreetr, bookyear1884
