The object of earth leakage protection for mines

Abstract

In the course of a recent series of electrical inspections, it has become increasingly obvious that while the managements of many mines have, without hesitation, complied with the Departmental requirements regard ing the provision of earth leakage protection, the main object of the requirement is not fully understood. On several occasions the Department has been asked how it justifies the introduction of earth leakage protection as a safety measure, with an allowable fault current trip value in the order of 3 per cent, which, on a circuit carrying a full load of 200 amperes, would amount to 6 amperes.