Safe separation

Safe isolation of circuits exists when a single fault does not lead to the voltage crossing over into that of another circuit. Safe isolation is defined according to IEC/EN 61140, IEC/EN 60947-1 in conjunction with IEC 60664-1 and is specified as rated impulse with respect to the degree of pollution. The rated impulse withstand voltage is the voltage value according to which the clearances and creepage distances are rated. It is determined depending on the overvoltage category to which the electrical equipment is assigned.