Performance three-phase ground fault circuit interrupter

A device comprising:

• a ground fault circuit interrupter connected between a power supply and a load, the ground fault circuit interrupter including an alternating current (AC) contactor and a current transformer each connected to a plurality of conductor lines, wherein the plurality of conductor lines are connected to the power supply and the load;
• and
• a control circuit of the ground fault circuit, the control circuit comprising:
• a current transformer coupled to the plurality of conductor lines, wherein the current transformer is operable to output a secondary current corresponding to a primary current magnitude of an electrical current not flowing to the load, and wherein the AC contactor is connected between the power supply and the load;
• and
• a zero cross detection circuit operable to:
• generate an interrupt at each of a plurality of zero crossings for a microprocessor;
• and
• determine whether to open one or more contactors of the AC contactor in a predetermined optimum interval calculated with respect to a plurality of zero crossing points;
• wherein the zero cross detection circuit and the microprocessor are operable to determine whether a time lapse between two consecutive interrupts exceeds a predetermined threshold and to send a trip signal to the contactor control circuit to open the one or more contactors of the AC contactor.

A three-phase ground-fault circuit-interrupter (GFCI) device, comprising:

• a plurality of conductor lines connected between a power supply and a load, each of the plurality of conductor lines coupled to an alternating current (AC) contactor and a contactor control circuit, wherein the contactor control circuit is operable to open and close one or more contactors of the AC contactor;
• and
• a current transformer coupled to the plurality of conductor lines, wherein the current transformer is operable to output a secondary current corresponding to a primary current magnitude of an electrical current not flowing to the load;
• and
• a zero cross detection circuit operable to:
• generate an interrupt at each of a plurality of zero crossings for a microprocessor;
• and
• determine whether to open the one or more contactors of the AC contactor in a predetermined optimum interval calculated with respect to the plurality of zero crossing points;
• wherein the zero cross detection circuit and the microprocessor are operable to determine whether a time lapse between two consecutive interrupts exceeds a predetermined threshold and to send a trip signal to the contactor control circuit to open the one or more contactors of the AC contactor.