a current sensor for measuring medium - voltage currents . the current sensor includes an input terminal configured to receive a current , an output terminal configured to transmit the current , a closed core made from a magnetic material and comprising a gap , at least one conductor operably connected to the input terminal and the output terminal and passing through the closed core , the at least one conductor sized to carry the current , and a molded case of solid dielectric material configured to encapsulate the closed core and the at least one conductor , wherein the gap and the terminals are not encapsulated by the molded case . the molded case is dimensioned such that internal and external spacings defined by the molded case are suitable for continuous operation with a medium voltage current as applied to the terminals and the at least one conductor while the core is at ground potential .