Test Methodology for Determining Specific Energy of Low Voltage Automatic Circuit Breakers.

Problems connected with the proper measurement of I**2t and the choice of the appropriate short circuit test sequence are analyzed and experimentally checked. An analysis of the result, including the influence of the circuit elements associated with the automatic circuit breaker, follows. Such an analysis seems to be useful since it emphasizes several disagreements existing between technical needs and the codes even if these are going to increase their effectiveness. Test measurements performed on many automatic circuit breakers made in different industries have been carried out at the shortcircuit laboratory of the Electrotechnical Dept. of the University of Naples.