In electric power distribution, a recloser, or autorecloser, is a circuit breaker equipped with a mechanism that can automatically close the breaker after it has been opened due to a fault. Reclosers are used on overhead distribution systems to detect and interrupt momentary faults. Since many short-circuits on overhead lines clear themselves, a recloser improves service continuity by automatically restoring power to the line after a momentary fault.
Is autorecloser a relay? NO! Autorecloser is not a relay! It is an inbuilt mechanism of circuit breakers. The mechanism starts a timer as soon as the line trips and then a close command is given to circuit breakers. We can also conclude that autorecloser is associated only with single phase to ground transient faults and it is related to CLOSING a circuit breaker and NOT TRIPPING!!