Protective relay /prəˈtɛktɪv ˈriˌleɪ/ – an automatic device that activates at certain values of the affected input quantities, the relay is used in protection schemes and non-normalized modes of eul and electrical installations.
Ex. In mining operations, a protective relay serves as a critical component in safeguarding electrical systems, detecting faults, and ensuring the safety of personnel and equipment in potentially hazardous environments.