According to the IEC60947-2, if the making capacity (Icm) is equal to the value specified in the attached file ,it is not
imperative to have a marking on the MCCB concerning the Icm value.
imperative to have a marking on the MCCB concerning the Icm value.
This is the reason why there is no information about the Icm concerning the marking and concerning the catalog.
Refer the snapshot-
Refer the snapshot-
As an example –
For the Compact NSX, the short circuit breaking capacity at 440V is 130KA, then Icm can be calculated by the
formula (as per attached IEC document)---
formula (as per attached IEC document)---
=> Icm = 2.2 x Icu = 2.2 X 130= 286 kA rms.