Electric Wiring for the Use of Architects, Underwriters, and the Owners of Buildings (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1896 Excerpt: ...insulation, because it is this part of the circuit that is most likely Fio. 34. Fio. 36. Fig. 36. Showing Service Entrance. Snap-switch without cover. to be near cornices, awnings, etc., and because in passing through holes exposed to moisture there is liability of leakage. "Drip-loops" are loops in the wire just before it enters the building. (Figs. 34 and 35.) Water gathering on the wire will run to the lowest point, and where there are drip-loops this water will drip off instead of running into the holes in the wall, which would increase the danger of leakage. It is required that the holes, through which the wires pass, be bushed with non-combustible "insulating-tubes" made of glass, porcelain, or similar material (Fig. 14) because time and exposure do not cause their deterioration; and when, for any reason, leakage does occur over their surfaces, they will not char or burn, or become better conductors. The tubes are slanted upward toward the inside of the building so that there will be no tendency for the water to enter. Moisture is further provided against by winding about the wire and the end of the tube "tape" made of insulating material. This tape is adhesive and can be made effectually to seal the end of the tube, if it be afterward thoroughly painted with waterproof paint. A "service-switch" is a switch in the service-wires, by which all connection between the main distributing wires in the street and the wiring in the building may be broken. (Page 80.) "Snap-switch" is the name given to the small circular switches ordinarily used to turn incandescent lamps on and off. One form is shown in Figure 36. When the handle is moved slightly, a spring of considerable strength comes into play and snaps the ...