Protection relays are electronic components designed to prevent unnecessary trips, isolate faults and protect motors, breakers, and other equipment.
Modern protective relays are microprocessor-based, and use inputs and settings to intelligently compare measurements to setpoints and produce a desired output. Inputs can include variables like current, voltage, resistance and temperature. If any of those values exceed a prescribed setpoint, the relay can trigger an output like an alarm, an indicating light, a network communication, and even turn another device on or off.
Because modern protection relays use digital technology to operate, they can produce quick, reliable, repeatable outputs far more frequently over a longer lifetime. They also provide better accuracy to eliminate nuisance trips, reduced maintenance needs to improve uptime, and better efficiency to cut costs and save panel space.