Short Circuit Rating
Short Circuit Rating
(OP)
When we talk about SC rating of a piece of electrical equipment, such as switchboard, it is not quantified with a maximum allowable time duration. However, when we apply the insulated power breakers in low voltage power distribution switchboard, those power breakers could withstand SC up to 0.5 or 1 second. Is it given that switchboards are constrcuted to withstand published SC level up to one or more seconds? I couldn't find anything on NEMA regarding this. Thanks.






RE: Short Circuit Rating
RE: Short Circuit Rating
RE: Short Circuit Rating
RE: Short Circuit Rating
Molded case circuit breakers can be used to protect UL891 switchboards or UL1558 switchgear because they are required to have instantaneous trip.