. Electrical world. le-pole, high-tension switches operatedfrom the third side to control the transformers. The fourth sidehas two marble panels, the upper one carrying two double-pole, low-tension switches for transformer control, and protective devices, andthe lower panel a double-pole switch for the outgoing low-tensioncables as well as safety contrivances. The houses arranged for overhead work are, in addition to theabove, equipped with lightning arresters. Besides these transformer stations there is also one located at thecenter of the city. It is reached by ladder from the street surface
. Electrical world. le-pole, high-tension switches operatedfrom the third side to control the transformers. The fourth sidehas two marble panels, the upper one carrying two double-pole, low-tension switches for transformer control, and protective devices, andthe lower panel a double-pole switch for the outgoing low-tensioncables as well as safety contrivances. The houses arranged for overhead work are, in addition to theabove, equipped with lightning arresters. Besides these transformer stations there is also one located at thecenter of the city. It is reached by ladder from the street surfacethrough a shaft covered by wooden and iron covers. This roomcontains four transformers with switchboard and arrangements forventilation and sewerage. There are in use 28 transformer stationsusing 33 transformers, taking 630 kw. .^s the tension of the two-wire system is 120 volts and of thethree-wire system 240 volts, all transformers have two secondarywindings, which can be arranged in parallel for the former system. -SECONDARY SIDE OF TRANSFORMER HOUSE. FIG. 6.—TRANSFORMER HOUSE. FIG. 7.—HIGH-TENSION SIDE OF TRANSFORMER HOUSE. for lighting and small power work. They are carried in woodencasings over the iron bridge to the shore. Four of these cableshave a cross-section of 2 x 60 mm. and two are 2 x 20 mm. Eachcable is double and concentric, one part being for the outgoing cur-rent and the other for the return. One circuit, forming the core of the cable, consists of copperstrand insulated and lead-covered. The other circuit consists ofcopper strand spun around the inner lead covering. This strand is I also insulated and protected by a double cover of lead. To prevent in- I jury in handling, the complete cable is covered with asphalted linen. I The resistance between the inner and outer cables is 1,120 megohms I and between outer cable and earth 1,140 megohms. Both primary and secondary cables are laid in clay pits filled withfine sand. When primary and secondary cables are
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectelectri, bookyear1883
