A relay contactor is provided and includes a shaft assembly comprising a plate, which is movable between an open position at which the plate is displaced from leads and a closed position at which the plate contacts the leads and an actuation system configured to selectively move the plate into the closed position. At least one of the shaft assembly and the actuation system is configured such that, as the plate moves into and away from the closed position, a movement of the plate relative to the leads comprises at least a non-linear, rotational or an abnormally linear component.

A progressively contacting switch includes a set of contacts connected to an input. The set includes a first sacrificial contact formed of a first metal and a first conducting contact formed of a second metal. The switch further includes a movable set of contacts connected to an output. The movable set includes a second sacrificial contact formed of the first metal and a second conducting contact formed of the second metal. The switch includes an element configurable to connect the movable set of contacts such that the first sacrificial contact connects to the second sacrificial contact at a first time, thereby causing a current to flow from the input to the output, and while the first sacrificial contact remains connected to the second sacrificial contact, the first conducting contact connects with the second conducting contact at a later time.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

A progressively contacting switch includes a set of contacts connected to an input. The set includes a first sacrificial contact formed of a first metal and a first conducting contact formed of a second metal. The switch further includes a movable set of contacts connected to an output. The movable set includes a second sacrificial contact formed of the first metal and a second conducting contact formed of the second metal. The switch includes an element configurable to connect the movable set of contacts such that the first sacrificial contact connects to the second sacrificial contact at a first time, thereby causing a current to flow from the input to the output, and while the first sacrificial contact remains connected to the second sacrificial contact, the first conducting contact connects with the second conducting contact at a later time.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

A system for thermionic arc extinction via anode ion depletion. The system includes a fixed terminal end including at least a fixed conductor containing at least a fixed contact. The system includes a moveable terminal end including at least a moveable conductor containing at least a moveable contact. The system includes a body including an inner compartment, wherein the inner compartment includes at least an arc shield housing at least two arcing contacts, the at least two arcing contacts including at least an anode contact and at least a cathode contact.

A system for isolating a fault in a direct current (DC) grid using thermionic arc extinction. The system includes a DC grid that includes a transmission line. The DC grid also includes a plurality of current interrupters disposed on the transmission line. Each of the plurality of current interrupters on the transmission line are electrically coupled to one another in series. At least one of the current interrupters includes a fixed terminal end and a moveable terminal end. Further, at least one of the current interrupters has an arc shield housing at least two arcing contacts. At least one of the arcing contacts comprises a first conducting material that has a first vaporizing point.

A system for isolating a fault in a direct current (DC) grid using thermionic arc extinction. The system includes a DC grid that includes a transmission line. The DC grid also includes a plurality of current interrupters disposed on the transmission line. Each of the plurality of current interrupters on the transmission line are electrically coupled to one another in series. At least one of the current interrupters includes a fixed terminal end and a moveable terminal end. Further, at least one of the current interrupters has an arc shield housing at least two arcing contacts. At least one of the arcing contacts comprises a first conducting material that has a first vaporizing point.

A switchgear having bus transfer current switching capability by turn and twist mechanism includes a contact system for electrical current conduction and bus transfer switching. The contact system has fixed and movable contact assemblies. Each contact assembly comprises includes main and arcing contacts. The arcing contacts are for bus transfer switching. The movable contact assembly comprises includes a current path pipe and an end piece. The current path pipe is a cylindrical pipe, and the end piece is a rectangular block. The movable contact assembly includes a movable main contact provided on the rectangular block, and a movable arcing contact provided at the end of the cylindrical pipe on a portion about the periphery. During engagement, the cylindrical pipe turns about a first axis to bring the contact assemblies proximal to each other, and twists about a second axis for engagement of the main contacts.