Suggestion to the original posting marked by ///\\Would you please explain your understanding for the theory of operation of the current limiting circuit breakers?
///The current limiting circuit breaker is supposed to be an approximate equivalent to a current limiting fuse, which some circuit breaker actually have to attain the current limiting circuit breaker time current characteristics including the peak let-through. As mentioned in above posting, there are circuit breakers that are current limiting, e.g. magnetoelectric type acting very fast within the first quarter of a cycle. DC circuit breakers tend to be all fast, therefore, they tend to be current limiting.\\Is their contacts impedance higher than other normal circuit breakers?
///The contact impedance is somewhat secondary aspect since the contact impedance or resistance is very small, e.g. 18microohm (for 4000A rating) or so depending on the circuit breaker or switchgear current rating.\\Or they interrupt the fault current earlier?
///Yes, very earlier.\\How they could be working with cascading?
///The upstream circuit breaker has to have bigger let-through than the downstream circuit breaker. Contact manufacturers for details since this is not very frequent application, or attempt to analyze let-through characteristics.\\\