GB147594A - Improvements in apparatus for starting and protecting continuous current motors - Google Patents

Abstract

147,594. Krupp Akt.-Ges., F. May 14, 1919, [Convention date]. Controllers, electro-magnetic actuating mechanism for; with overload release.-A combined automatic starter and overload-release for a continuous-current shunt-wound motor comprises two windings in opposition on a core E which control not only the overload and starting contact e<1>, but also a second magnet core J which closes a contact i' to out out a starting-resistance C. The tension winding d<2> is permanently across the mains and is closed by a switch F. When a resistance H is cut out by means of a switch G, the current in the tension winding d<2> closes the starting-contact e<1> upon the contacts d<3>, d<4> against a spring d<5>. As the motor speeds up and the strength of the armature current drops, the current in the tension winding d<2> gradually becomes sufficient to overcome both the opposite tractive force due to the current in the main winding d' and also the force of the spring i', and closes the contact i<1> against the points i<2>, i<3>, thereby cutting out the starting-resistance C, and allowing the motor to attain its full working speed. The starter can be opened at any time bv pulling-out the switch F and so de-energizing the tension winding d<2>, whereupon the parts return to the position shown on the Figure.