Sectionalizer

A sectionalizer is a downstream protective device, usually a disconnector or cutout equipped with a tripping mechanism triggered by a counter or timer, that cooperates with a recloser or circuit breaker. It detects and counts fault current interruptions performed by the recloser, and after a predetermined number of interruptions, the sectionalizer opens, isolating the faulty section of the circuit. A sectionalizer is generally not rated to interrupt fault current itself, but often has a larger basic insulation level, allowing some sectionalizers to be used as a point of isolation.