Other Situations Of Setting Current Of Low Voltage Column Mounted Circuit Breaker

When the distribution line is long, the short-circuit current is often small. The setting current of the Lv Pole Mounted Circuit Breakers instantaneous or short-delay release at the end should be less than the calculated value of the short-circuit current. (That is, the short-circuit current should not be less than 1.3 times the setting current of the instantaneous release - this can be done with a smaller multiple setting).
The upper and lower level protection devices used in the distribution line should have selective action: each level should be able to coordinate and cooperate. However, for the protection devices of non-important loads, non-selective cutting can be used.