Central Station Volume 7

Central Station Volume 7

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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 edition. Excerpt: ...by means of triggers or toggles, which are called 'circuit breakers.'" The general proposition that a circuit is broken by a hand operated or automatic device, -covers the definition of a switch, along practical lines, whether it is hand operated or automatic, in either opening or closing its utility is governed largely by its durability, other things being equal. Switches for Small Currents.--The types of switches used for small currents belong to the category of quick break single and double pole. The conditions prevailing in electric light service, within the structure to be lit, are such that fire risks have had a determining effect upon the general design of such switches. The Underwriters have outlined in clear, practical terms the amounts of current suited to certain circuits, and the switches in consequence are designed with reference to this particular service. The predisposing factors in all such instances are naturally the amount of current and the potential. The numbet of breaks, the heaviness of the parts, the quickness of action, and the size and convenience of the switch as a whole, are governed by the requirements of the current and service. Voltage a'ld Length of Break.--The circuular miles allowed for various currents, determine the cross sections of parts of the switch, particularly as regards the drop in its parts, and the temperature, as a whole. But the speed of breaking and the distance between the parts broken, to insure safety from arcing requires separate treatment. In alternating current service it is evident that the power factor plays an important part in the design of a switch, for the reason that the arc will be able to lengthen at the point of break in proportion to the inductive electromotive force...show more

Product details

  • Paperback | 198 pages
  • 189 x 246 x 11mm | 363g
  • Rarebooksclub.com
  • United States
  • English
  • black & white illustrations
  • 1236751337
  • 9781236751331