ELECTRICAL FOUR-CORE CABLE Russian patent published in 1998 - IPC

FIELD: electrical engineering. SUBSTANCE: invention solves problem of design of high-efficient cable thanks to peculiarities of distribution of current in case of single-phase short-circuit which emerge owing to ferromagnetic component of bimetal PEN conductor that redistributes thermal effect to side conductive parts. In this electric four-core cable fourth core has smaller section and is used in the capacity of PEN conductor ( zero ) shunted by side conductive parts. PEN conductor is bimetal conductor composed of conductor metal, for example, copper or aluminum, and ferromagnetic metal, for example, steel. Heat released by fourth core of cable with passage of short-circuit current through cable is dissipated by fourth core of cable at low values of current. With rise of short-circuit current above level permissible for this cable heat is dissipated additionally by conventional ferromagnetic core formed by part of fourth core and separate external structure shunting it. EFFECT: design of high-efficient cable.