Figs. 848 to 850.—Crossing of wires. Where wires cross each other, tubes should be used except in case of large stiff wires as in [fig. 848]; here one wire may be bent down and carried under the other; [fig. 849], short bushing strung on the wire—this method is usually unsatisfactory, especially where a large number of wires cross each other; [fig. 850], wires crossing each other through tubes. Flexible tubing, such as circular loom may be used in crossing wires in dry locations. Insulators should always be provided where wires cross to support the wires, thus preventing the upper wires sagging and touching those below.
Figs. 851 to 853.—Methods of wiring across pipes. The wires should preferably run over rather than under the pipes. Fig. 851 shows crossing with circular loom, and [fig. 852], one in which a tube is used. Both of these methods are satisfactory in the case of gas pipes, but for steam pipes or water pipes which are liable to leak or sweat and drip moisture, the crossing should be above as shown in [fig. 853]. On side walls where vertical wires run across horizontal water pipes, the latter should be enclosed and the moisture deflected to one side.
Ques. How should wires be protected when run vertically on walls?