Book Description

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. 1910 edition. Excerpt: ...to connect with the cars. When in A. C. zone the change-over switch opens the connection to the third rail shoes and closes the connection to a small transformer which 'can be connected to either or both of the main transformers by single-pole, double-throw knife switches. Under normal conditions, both of these switches are in the up position and the heaters draw half of their current from each transformer. When both switches are down, the heating transformer is cut off. Should a main transformer become disabled, placing one switch in the up and the other in the down position, it throws the heating transformer entirely on one of the main transformers. CHANGE-OVER Swrrcm-: s.---These are magnetically operated switches, which automatically pro dnce certain rearrangements of circuits when changing from A. O. to D. C. power and reverse. For instance, when on the tenth notch of the controller, with the change-over switch in D. O. position in the switch group No. 1, switch 5 is closed; yet in A. C. zone, with the. change-over switch in the other position, switch 5 would not close, and switches 6 and 7 would. In like manner, in groups No. 2 and No. 5, switches 8, 9, 18 and 19 can only close if the change-over is in D. O. position. Yet, with the controller in the identical position, if the changeover switch were thrown, then only switches I to IX could close and switches 8, 9, 18 and 19 would be locked out. These switches prevent A. C. from getting into D. C. apparatus, and D. C. from getting into ' A. O. apparatus, provided only one kind of current gets into the locomotive. RELAYs.--These three relays interlock the control circuits between A. O. and D. C. power, making it impossible to throw both A. O. and D. O. apparatus at the same time....