| 摘要 |
An apparatus for detecting a leakage current flowing between at least one supply conductor of a multi-conductor electricity supply to load and non load currents carrying electrical conductor nominally insulated from the supply conductor. The apparatus includes a current transformer having a primary winding and a secondary winding. The primary winding is connected between the non load current carrying conductor and at least one other supply conductor so that leakage current flowing between the at least one supply conductor and the non load current carrying conductor flows through the primary winding to the other supply conductor. An electromechanical relay has a set of normally-closed contacts in series with the electricity supply. Circuitry connecting the secondary winding of the current transformer and the relay is provided so the relay is actuated by a current induced in the secondary winding by a leakage current meeting certain criteria as to magnitude and/or duration.
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