Electical Meterman's Handbook

Electical Meterman's Handbook

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Description

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. 1912 edition. Excerpt: ...test may be performed on element B by changing the connections of its potential coil from BC to BA, Sixth, if it is found from the above tests that the power-factor is greater than 50 per cent, connect the current coils so that each element tends to run forward. If the power-factor is less than 50 per cent, connect the current coil of the slower element so that it tends to run backward and the current coils of the faster element so that it tends to run forward. If the changes are made while the circuits are alive, care should be taken never to open the secondary circuit of a current transformer. Serious personal injury may result or the magnetic state of the iron may be altered sufficiently to materially change the ratio. These dangers may be avoided by always short circuiting the current transsecondary before opening the meter circuit. Where the connections cannot be easily traced, ringing out by the ordinary magneto method is the most reliable means of identifying the various circuits. Watt-hour meters, installed on consumers' premises, with voltage and current transformers, must be correctly calibrated with respect to the energy in the high-tension circuit. A correct calibration is obtained directly by connecting the working standards in the high-tension circuits of the transformers (Figs. 292 and 293). In such tests the impedance in the low-tension circuit of the transformers should be the same as in service. This procedure should be followed where feasible. In the case of high voltage, or heavy current lines, and also in some other cases where the character of the installation is such as to make high-tension tests difficult or impossible, recourse may be had to low-tension tests; provided, however, that the transformer errors are determined...show more

Product details

  • Paperback | 214 pages
  • 189 x 246 x 11mm | 390g
  • Rarebooksclub.com
  • Miami Fl, United States
  • English
  • black & white illustrations
  • 1236554566
  • 9781236554567