Considerations regarding testing of low voltage equipment at electrical arc and thermal factor actions

Abstract

Within paper there is made a synthesis of IEC standards requirements for testing at overload and short-circuit currents of low voltage equipment: switches, disconnectors, switch-disconnectors, contactors, fuses and fuses combinations with these. After this there is presented testing circuit for withstand ability at overload and short-circuit currents passing of low voltage equipment for a large range of currents through realisation of a special circuit for load adjustment. Also are described experiments performed on low voltage fuses-as type tests-and are established appreciation criteria regarding the behaviour at electric arc action due to overload and short-circuit currents.