JPS54155438A - Power distributor - Google Patents

Abstract

PURPOSE: To make the promotion of miniaturization with a less requirement of the number of limiters, by means of such arrangement that, with a current limiter intermediately installed to lines of two phases of the three-phase lines, the connection of a short-circuit line be provided in the remaining phase.

CONSTITUTION: Into lines of two phases of the three-phase output lines of a main breaker 1, is intermediately inserted a current limiter 4, for presenting a non-linear impedance characterostic where the impedance rapidly increases when a conduction current increases, and in the remaining one phase is provided the connection of a short-circuit line 7. When caused a short-circuit fault in the secondary side of a branch breaker 3, the fault current flows in the branch breaker 3 through the main breaker 1, the current limiter 4 and the short-circuit line 7. With the fault current exceeding a level determined by the limiter 4, a rapid increase is caused in the resistance value of said limiter that suppresses the increase of the fault current. At this time, the branch breaker 3 is to disconnect the fault current making the fault circuit isolated. In such constitution, a requirement of only two current limiters, good enough for the three-phase use, can promote a miniaturization as compared with the method in which three current limiters have been usually required.

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