Why are switches installed in distribution feeder circuits?

• A. To redirect power flows for load balancing
• B. To sectionalize or isolate a section for repairs
• C. To reduce the system's susceptibility to fault current
• D. Only A and B

Answer: (D)

Switches in distribution feeders are placed to give operators flexibility: they can reconfigure how power is routed to balance loads across feeders and to isolate or sectionalize a portion of the circuit for maintenance or after a fault. This lets the system carry more of the load where capacity exists and shut off only the affected section, keeping the rest of the network energized.

While opening a switch can interrupt a fault current path, switches aren’t themselves used to reduce the inherent fault current level of the system. The fault current is set by the sources and the network impedance, and the switch mainly provides isolation and reconfiguration capability. That’s why the best answer covers both load balancing and sectionalizing, not reducing fault current susceptibility.