An arc fault detector includes a shunt resistor deployed in a protected circuit, an arc discriminator sensing voltages across the shunt resistor and producing an arc indication deduced from current variations associated with parallel and series arc faults, a signal transformer buffering the arc detection signal and producing a pulse, a switch transient detector sensing a voltage differential across load switches and producing a pulsed switch transient signal when the voltage differential across load switches exceeds a reference value, a line interrupter, such as a static relay, a switch controller including logic gates generating a trip signal based on predetermined criteria, and a manual switch for resetting the line interrupter. An embodiment comprises a voltage sensing coil enveloping a toroidal core to detect current variations in conductors passing through the core.