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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. 1907 Excerpt: ...to make a " bunch " test of all the feeders, mains, and branch circuits from the point where they start. A test should first be made between the conductors themselves; that is, in a twowired system between the positive and negative leads and in a three-wired system between the two outsides and between each outside and the middle conductor. Then a ground test should be made between each of the two conductors, in the two-wired system, or between each of the three conductors in the threewired system, and the ground. If a short circuit between the conductors, or a leakage between the conductors and the ground, be discovered, the proper method of locating the trouble is by the method of elimination. To accomplish this end, each of the feeders, or mains, is successively cut out of circuit by opening the switch (or removing the fuse) controlling the same. When, by opening a certain circuit, the short circuit, or ground, disappears, of course the trouble is known to be on that feeder or main. By following this main up to the various centers of distribution through the building, the center of distribution at which this trouble is located can be discovered; and in similar manner the branch circuit and the outlet at which the trouble exists can be found. In many cases it will be found that the slate used in the panel-boards for cut-outs contains metallic veins and that a leakage will result between the bus-bars. For this reason, it would be well if all panel-board makers would test their panelboards before shipping them from their shops, as it is usually impossible to remove this trouble, and a new panel-board must generally be substituted for the one found to be defective. As a rule, most short circuits and grounds will be located at the outlets, where the ...