Services & DistributionQuestion 73 of 521
The short-circuit current rating (SCCR) of equipment such as a panelboard means the equipment can:
a.Withstand the available fault current at its terminals without extensive damage until the overcurrent device clears
b.Carry continuous load indefinitely
c.Interrupt fault current by itself
d.Operate at 125% of its rating
Explanation
Per 110.10, the SCCR ensures the assembly can safely withstand the let-through energy of the available fault current until the protective device opens, preventing extensive damage. It is not a measure of continuous carrying capacity, and the panelboard itself does not interrupt the fault.
Law Reference: 2023 NEC §110.10Practice all 521 questions free — no signup required.
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