What is a mechanical device used to isolate permanent faults on single-phase lines called?

The mechanical device used to isolate permanent faults on single-phase lines is known as a sectionalizer. Sectionalizers are designed to detect and isolate faults on overhead distribution systems. When a fault occurs, the sectionalizer monitors the line and, if the fault is sustained, it interrupts the circuit, effectively isolating the segment of the line experiencing the fault. This allows for safe maintenance and repairs while minimizing the impact on the rest of the distribution system.

The role of a sectionalizer is particularly important for improving the reliability of the power supply and ensuring that faults do not cause unnecessary outages in unaffected areas of the system. While isolators and disconnect switches serve to separate parts of the system for maintenance, they typically do not detect faults or operate automatically. Reclosers, on the other hand, are designed to automatically attempt to restore service after a temporary fault occurs but may not be specifically tailored to isolate permanent faults like a sectionalizer would be.