Why the breaking capacity for C60a is 3000 Amps according to IEC 698 and 5000 Amps according to IEC 947 ?
In IEC 898 standard the Icn breaking capacity must take into account the preferential values of 1500, 3000, 4500, 6000 Amps. In addition for IEC 898 standard, Icn (O-FO) and Ics (O-FO-FO)must be equal, for Icn values below or equal to 6000A. ==> For C60a mcb Icn = Ics = 3000Amps according to IEC898 standard
In IEC 947-2 standard, the Ics (O-FO-FO) value is free choice left to the manufacturer, with preferential values 100%,75%,50%,25% of Icu (O-FO). From the carried out tests, the best compromise for C60a is Icu=5kA with a Ics at 75%, i.e; 3.75 kA.
In IEC 947-2 standard, the Ics (O-FO-FO) value is free choice left to the manufacturer, with preferential values 100%,75%,50%,25% of Icu (O-FO). From the carried out tests, the best compromise for C60a is Icu=5kA with a Ics at 75%, i.e; 3.75 kA.