IEC 60670-24 Ed. 1.0 b:2005

This part of IEC 60670 applies to empty enclosures and parts of them for electrical accessories intended to be used with a rated voltage not exceeding 400 V and a total incoming load current not exceeding 125 A for household and similar fixed electrical installations, where a maximum capability to dissipate power in normal use is declared by the manufacturer. These enclosures are intended for housing protective devices and devices with or without power dissipation. They are intended to be installed where the prospective short circuit current does not exceed 10 kA unless they are protected by current limiting protective devices with a cut-off current not exceeding 17 kA.