OVERCURRENT RELEASE Russian patent published in 2001 - IPC

FIELD: electrical engineering; circuit breakers. SUBSTANCE: overcurrent release has electromagnet assembled of magnetic core, wound coil supplied with current from circuit under protection, and hermetically sealed ferromagnetic shell placed inside coil and used as armature. Ferromagnetic shell is filled with heat-sensing liquid whose coefficient of volumetric expansion is maintained constant within comprehensive temperature range; shell accommodates spring-loaded rod whose end protrudes beyond shell and is provided with reset limiter in the form of locking ring. Ferromagnetic shell is also provided with reset limiter and control member that functions to control response of release to short- circuit currents. Trip-free mechanism of release has control member used to control response of release to overload currents. Control member for responding to short-circuit currents is made in the form of stud installed in threaded hole on butt end of ferromagnetic shell and passed through hole in reset limiter. Stud is provided with spring and adjusting nut. EFFECT: enhanced precision and operating reliability with adequate pressure applied. 3 cl, 1 dwg