What is a sectionalizer primarily used for in the context of a distribution line?

A sectionalizer is primarily used to isolate a faulted section of a distribution line. In practical terms, when a fault occurs on a distribution line, the sectionalizer works in conjunction with protective devices such as circuit breakers to determine and isolate the section where the fault exists. This allows the rest of the distribution network to remain operational while maintenance crews address the trouble spot.

By automatically opening and isolating the defective section, the sectionalizer helps maintain overall system reliability and safety, minimizing the impact of outages on consumers. The ability to detect and respond to faults quickly is crucial for efficient power distribution and service continuity.

In contrast, surge protection devices are designed to manage transient overvoltages, while measuring current involves the use of ammeters or current sensors, which function in a very different capacity than a sectionalizer's role. Increasing voltage pertains to transformers and does not relate to the sectionalization of a distribution system. This distinction highlights why the sectionalizer's primary function is fault isolation, making it a vital component in distribution line management.