Page 176 - B_ELSB_Cat_2022_01_MCBs

1/176 ELECTRICAL INSTALL ATION SOLUTIONS FOR BUILDINGS - TECHNICAL DETAILS 9AKK 107991 A8329
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MCBs technical details
Coordination tables: selectivity

Functional diagram of selective main circuit breakers S 750 (DR)

Back-up protection Short circuit discrimination
Selective main circuit breakers of the S 750 DR series are When ABB miniature circuit-breaker are used in combination
capable of switching off short-circuit currents with the S 750 DR, higher short-circuit currents can be
of up to 25 kA automatically in networks with a rated voltage disconnected than indicated as permissible rated
of 230/400 V. Back-up protection is necessary only when switching capacity of the device. Considering the values
the prospective short-circuit current may exceed 25 kA given in the table, the S 750 DR operates selectively
prosp. at the installation point. Further information on with respect to the combination with the final device.
back-up protection on request. If other MCBs are used selectivity for 6 kA and 10 kA devices
is available up to the rated switching capacity of the final
device.