. Operation of trains and station work and telegraphy . , protect the metaflic parts against in-jury by arcing. Triple Contact.—Upon the top of the iron frame ofthe automatic generator switch is mounted a triple con-tact, consisting of a three-part segmental socket and aconical plug fitting the same. The function of the triplecontact is to short-circuit the lamp bucker and seriesfield, thus avoiding the drop that would otherwise takeplace in the lamp circuit when the battery was discharg-ing, and to render the bucker inoperative below operatingspeeds, when the generator switch is open. The plu
. Operation of trains and station work and telegraphy . , protect the metaflic parts against in-jury by arcing. Triple Contact.—Upon the top of the iron frame ofthe automatic generator switch is mounted a triple con-tact, consisting of a three-part segmental socket and aconical plug fitting the same. The function of the triplecontact is to short-circuit the lamp bucker and seriesfield, thus avoiding the drop that would otherwise takeplace in the lamp circuit when the battery was discharg-ing, and to render the bucker inoperative below operatingspeeds, when the generator switch is open. The plug is raised and lowered by means of a tail-rodattached to the plunger of the switch. When the plungeris down and the generator switch open, the plug con- HEATING AND LIGHTING CARS 199 nects the three segments together. When the plungerand plug are raised by the lifting coil, the triple contactis broken. The plug is insulated from the tail-rod anda flexible conductor permanently connects the plug withan insulated terminal, mounted on a tarnsite 95. GENERATOR SWITCH WITH FOUR-CIRCUIT PANELBOARD IN DOUBLE SECTION IRON BOX, One lead of a resistance coil is connected to this in-sulated terniinal, and tlie other lead is connected to therear segment of the triple contact. The negative lead ofthe generator is also connected to this segment. Theleads of the lifting coil are connected, respectively, to thepositive main contact, and the terminal to which the flexi-ble conductor is attached. Thus it will be seen that when 200 RULES FOR MOVEMENT OF TRAINS the plug establishes the triple contact it also short-circuitsthe resistance coil. When the plug is raised, it throwsthe resistance into series with the lifting coil. Two advantages result from inserting resistance intothe lifting coil circuit: First, to reduce the current andconsequent heating in the coil, which would otherwisechange its resistance and alter the adjustment of theswitch; second, to reduce the magnetizing effect of
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroa, bookyear1919
