What is the primary function of a sectionalizer in an electrical circuit?

The primary function of a sectionalizer in an electrical circuit is to interrupt a fault current. Sectionalizers are protective devices used within electrical distribution systems to isolate faulted sections of the circuit. When a fault occurs, the sectionalizer detects the fault current and will open to disconnect the affected section from the rest of the system, allowing for maintenance and preventing further damage to the electrical infrastructure.

In this context, the sectionalizer relies on coordination with circuit breakers and reclosers to ensure a safe and effective response to faults. It typically does this by monitoring the current flowing through it; if it detects a sustained fault current, it will open the circuit, effectively isolating the issue and enabling continued service elsewhere in the system.