There are two types of breaking capacity indicators of circuit breakers: rated ultimate short-circuit breaking capacity Icu and rated operating short-circuit breaking capacity Ics. As a characteristic parameter, Ics does not simply consider the breaking capacity of the circuit breaker, but as a breaking index, that is, after breaking several short-circuit faults, it can still guarantee its normal operation. For molded case circuit breakers, there should be enough Icu to break the short-circuit current and trip the switch. According to the regulations, the Ics of the molded case circuit breaker is qualified as long as it is greater than 25%Icu. At present, most of the Ics of circuit breakers on the market are between (50%-75%) Icu, so for power distribution systems that do not require high power supply, only Icu needs to be considered.
Post time: Jul-21-2023
