During a fault, distribution automation may perform which action to isolate the faulted section?

• A. Close a feeder and tie switch to feed upstream
• B. Open all switches
• C. Reclose randomly
• D. Do nothing

Answer: (A)

When a fault occurs, the goal of distribution automation is to reconfigure the network so the faulted area is isolated while the rest of the system remains energized. Closing a feeder and a tie switch creates a backfeed path from an upstream source into the healthy portion of the feeder. This enables the protection system to isolate the faulted section by opening the downstream sectionalizing devices, so customers in the unaffected area keep power while the fault is contained. Opening all switches would unnecessarily disconnect large portions of the system, reclose randomly could reenergize the fault and cause damage or safety hazards, and doing nothing leaves the fault energised and can widen the outage.