In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. Types of Protective Relays: Protective relays are categorized by their mechanism (electromagnetic, static, mechanical) and function. Electromechanical protective relays at a hydroelectric generating plant. The relays are in round glass cases. Its main purpose is to safeguard electrical equipment like transformers, generators, and transmission lines from damage due to. An electrically operated switch like a relay plays a key role in controlling an electrical circuit through an independent low-power signal, otherwise used where a number of circuits should be controlled through the single signal.
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