How long is the relay protection return time
Its defining feature is zero intentional time delay (or minimal delay), with typical operating times of 20–50 ms, complying with IEC 60255-151 (Overcurrent Protection Standards) and IEEE C37. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. Time-graded protection is implemented using overcurrent relays with either definite time characteristic or inverse time characteristic.
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