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EddyWirbelstrom
Electrical
The short-circuit parameter which determines switchgear required short-circuit withstand rating is the peak ( ip ) or crest value of the ac current wave one half cycle after fault inception. This determines the mechanical forces the switchgear is subjected to.
Table 4 of AS3439.1 ( based on IEC60439-1 )defines the relationship between the rated peak withstand current ( Ipk ) and rated short-time withstand current ( Icw ).
eg. From Table 4 ; LV switchgear with a short-time withstand rating ( Icw ) of 63kA must be able to withstand a peak current ( ip ) of 138.6 kA.
Table 4 of AS3439.1 ( based on IEC60439-1 )defines the relationship between the rated peak withstand current ( Ipk ) and rated short-time withstand current ( Icw ).
eg. From Table 4 ; LV switchgear with a short-time withstand rating ( Icw ) of 63kA must be able to withstand a peak current ( ip ) of 138.6 kA.
