55. Foundations. dragged from their proper position under normal conditions of operation; all coils, connections, commutators, brushes, etc., belonging to different circuits shall be so insulated and protected that it will be impossible under the ordinary conditions of operation to cross or ground them; the dynamo(s) shall be rated with such margin of safety that they will not be in jured if subjected to an over-load of- -per } normal rating for a period of -;if (an) auxiliary dynamo(s) are required for the operation of the is they dynamo(s) specified above it } shall be subject to the same conditions. (See Note: p. 46, sec. 22.) The foundation(s) for the(se) dynamo(s) contractor of shall be built by the purchaser laid --, or of other material subject to the approval of the engineer, and shall be of sufficient length, width and depth to safely and firmly sustain their weight. For dynamos operating at voltages below the baseframe may be firmly and securely fastened directly on the foundation. For dynamos operating at voltages above --- the foundation shall be capped with a framing of well-seasoned timber securely fastened thereto, the baseframe being securely fastened to the framing or to the foundation through the framing; both framing and baseframe being secured in such a manner as to prevent lateral motion in either direction, and to give an even bearing surface at every point. If metal is used to fasten framing or baseframe to the foundation it shall be thoroughly insulated where it passes through them and at all places liable to come in contact with the dynamo shall be countersunk and covered with a moisture-proof insulating compound. 56. Instruments. All necessary excavating and filling, and the removal of all debris shall be done by the purchaser who shall also restore the floor in the following man ner: The height of the dynamo base-frame(s) above the floor line will be (See Note: p. 48, sec. 23.) namo There shall be provided with each dyone hand regulator for adjusting the pressure, made entirely of incombustible material; one ampere meter for indicating the current supplied by the dynamo; one voltmeter or pressure-indicator which shall remain constantly in circuit so as to indicate continuously the pressure at the point to which it is connected, and shall be so constructed that the scale is plainly visible at a distance of at least ; one insulating baseframe provided with rails and a suitable device for shifting the position of the dynamo to alter the belt tension; there shall be provided for the installation one ground detector, or if the circuits have no common junction one ground detector for each circuit which shall continuously indicate the insulation from the ground maintained on both sides throughout the system, and one pair of lightning arresters for the common circuits, or for each circuit if they are kept separate; there shall also be provided such brush jigs, switches, cut-outs, belts and other appliances as are requisite and proper for the operation of the system; all switches and cut-outs to be of the double pole type and mounted on incombustible bases. ers. For alternating systems there shall be 57. Convert provided the following numbers and sizes This contractor shall carry to the switchboard location at all regulator, exciter, auxiliary, and main wires, leaving the ends coiled up neatly, properly tagged and sufficiently long to make the necessary switchboard connections. All main wires shall have a capacity of at least C. M. per ampere, and no wire smaller than B. & S. or -B. W. G. shall be used. All regulator, exciter, and for systems carrying over volts all auxiliary and main wires, shall be insu lated with rying over all wires of systems carvolts shall be run where of opposite polarity shall shall be separated at least ; and where crossing each other, wires of other circuits or passing near metal pipes, girders, etc., shall be further protected by For systems carrying less than volts the main wires shall be of bare copper wire supported on porcelain insulators. |