A UPS system and mechanical switching arrangement therefor that is driven by an electromechanical actuator when a fault condition is detected thereby opening or closing a switch of the switching arrangement in response thereto within 8 milliseconds, preferably within 4 milliseconds, and more preferably within 2 milliseconds of a fault condition being detected. The UPS system has one switching arrangement for controlling current flow through a utility power path that is switched by an electromechanical actuator and another switching arrangement for controlling that is switched by an electromechanical actuator through an inverter power path that supplies an output-connected load with electrical power should a fault condition occur. The switching arrangements can be driven by a common electromechanical actuator or independent driven by separate electromechanical actuators enabling programmability of a plurality of different UPS system operating modes.