GB163094A - Improvements in electric cut out systems - Google Patents

Abstract

163,094. Enrich, F. S., and Serrano, C. P. Feb. 4, 1920. Cut-out systems.-Overhead conductors are protected by an electromagnetic cut-out arrangement comprising two electromagnets F, F<1>, Fig. 1, acting in opposition upon a movable armature G which carries a contact N adapted to complete, the circuit of the actuating-coils A of an electromagnetic switch B. One of the electromagnets F is connected between the guard wire P and an earth T; the other electromagnet F<1> is in an earthed branch off the main supply A<11> through a resistance L. The electromagnetic switch B, when no current flows through the actuating coils A, bridges over contacts D, D<1> in the connection from the main supply to the overhead conductor P<1>; when the coils A are excited, they raise the bridging contact and cut off the supply to the contactor P<1>. In action, the armature G is held up in the position shown by the combined effect of the upper magnet and a spring M against the effect of the lower magnet. If a breakage occurs with consequent loss of energy in the guard wire, the upper magnet becomes dead and the lower magnet, which is not affected, pulls the contact N into position for bridging stationary contacts I, I<1> and so exciting the coils A. A lamp or other signal O<1> is simultaneously set in action bv the closure of a pair of contacts K, K<1>. In order to re-set the apparatus, a switch L' is opened by hand, thus cutting out the magnet F<1>. The arrangement may be modified for three-phase lines by providing three electromagnets corresponding to A and controlled by three contacts on an armature corresponding to G.