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What is a current limiting circuit breaker?

FA112978

23 January 2021

Issue:
What is a current-limiting circuit breaker?

Product Line:
Molded Case Breaker, Powerpact

Resolution:
A current limiting circuit breaker is one that has been certified by UL to limit the let-through I^2t (I squared t) during a fault to not more than the I^2t available during a half cycle of prospective symmetrical short circuit current. Maximum let-through I^2t and peak current levels are published on curves available with the trip curves for the current limiting breakers.

The Schneider Electric current limiting breakers now available in North America are the Powerpact HJ/HL/HR, JJ/JL/JR, and LJ/LL/LR frame circuit breakers.