Current limiting resistor for circuit breaker

Abstract From the Canadian patent

Abstract of the Disclosure A current limiting iron wire resistor having a transformable resistance for a current limiting circuit breaker. Each pole of the circuit breaker includes said resistor in parallel with a pair of auxiliary contacts for current limiting which are in series with a pair of main contacts to open the circuit. The main contacts are separable upon operation of a thermally and electromagnetically operable tripping mechanism and the auxiliary current, limiting contacts separate only on occurrence of a high amplitude fault current above a preselected threshold value. When that value of fault current is reached, the tripping mechanism and associated components which operate …