Abstract: An inverter system having a dc input and an ac output has a fault sensor and switching provisions for diverting current to an additional path away from overloaded semiconductors of the inverter upon a fault. The system has a resonant inductance and capacitance circuit at the dc input, whose capacitance discharges through the inductance upon a fault and recharges with an opposite polarity to apply the reverse polarity to semiconductors of the inverter in an attempt to interrupt the fault. Initially the discharge of the capacitance is blocked by a second switching circuit until the fault sensor produces a fault indication signal, so that no portion of the initial charge of the capacitance is wasted by discharging into the faulting semiconductors of the inverter before the current diverting path is established.