Emax Low voltage air circuit-breakers - ABB Download Center

Primary and secondary distributionSelective protectionSolution with a trip unit without “double S”LV/LV Trans. 315kVATime-Current Curve @ 400V1SDC200314F0001MV CB (PR521)50 (I>): 50 A t=0.5s51 (I>>): 500 A t=0s6E2N 1250 PR122 T5V 630 PR222DS/PLSIG R1250LSIG R630L Setting 0.8 0.74Curve 108s 12sS t=constant Setting 3.5 4.2Curve 0.5s 0.25sI Setting OFF 7In the case of a short-circuit, the Emax E2 circuit-breaker andthe MV circuit-breaker will open simultaneously with this solution.Attention must be paid to the fact that, owing to the valueIk, function I of the E2 circuit-breaker has to be disabled (I 3=OFF)so that selectivity with the T5 on the load side is granted.6/6ABB SACE