Moreover, to protect against short circuits, primary relaying, the first line of defense, and backup relaying are used, which spring into action when primary relaying fails. Protective relaying equipment is described with the words “sensitivity,” “selectivity,” and “speed. A short circuit occurs when current flows through an unintended low-impedance p th, potentially leading to overheating, fire hazards, and equipment failure. Effective short circuit protection strategies involve using. Combines protection, sensors, control power, and circuit breaker in a single package Typically added to a breaker close circuit to prevent accidental reclosure after a trip. So this causes to flow heavy current throughout the relay coil and makes the protective relay function by simply closing its contacts.
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