A heat dissipation apparatus, system and method for an air circuit breaker (ACB) switchgear has at least one pair of primary contact toes constructed and arranged to connect to a terminal of the circuit breaker. A bus bar joint is connected to the primary contact toes. The heat dissipation apparatus comprises an evaporator clamped to the primary contact toes. A condenser is located at a higher elevation than the evaporator and at least two electrically isolating pipes fluidly connect the evaporator with the condenser. A dielectric fluid in the evaporator can be heated to a vapor state, with one of the pipes transferring the vapor to the condenser and the second pipe returning the condensed dielectric fluid back to the evaporator for cooling the at least one pair of primary contact toes.

A cooling apparatus is provided for a switchgear. The switchgear has one or more primary contacts constructed and arranged to connect to a terminal of a circuit breaker. The cooling apparatus includes an evaporator constructed and arranged to be associated with each primary contact. A condenser is located at a higher elevation than the evaporator. Fluid conduit structure fluidly connects the evaporator with the condenser. A portion of the fluid conduit structure defines a busbar tube electrically connected with an associated primary contact and defining a busbar of the switchgear. Working fluid is in the evaporator so as to be heated to a vapor state, with the fluid conduit structure being constructed and arranged to transfer the vapor to the condenser and to passively return condensed working fluid back to the evaporator for cooling the at least one primary contact and the associated busbar tube.

An electrical component may include an electrically conductive element and electrical insulation that at least partially surrounds the element and without contact. A heat pipe may be surrounded by the insulation at least at one end and may partially protrude from the insulation, wherein the part of the heat pipe protruding from the insulation protrudes closer to the central element than the insulation.

A heat dissipation apparatus, system and method for an air circuit breaker (ACB) switchgear has at least one pair of primary contact toes constructed and arranged to connect to a terminal of the circuit breaker. A bus bar joint is connected to the primary contact toes. The heat dissipation apparatus comprises an evaporator clamped to the primary contact toes. A condenser is located at a higher elevation than the evaporator and at least two electrically isolating pipes fluidly connect the evaporator with the condenser. A dielectric fluid in the evaporator can be heated to a vapour state, with one of the pipes transferring the vapour to the condenser and the second pipe returning the condensed dielectric fluid back to the evaporator for cooling the at least one pair of primary contact toes.

A bypass heat spreader includes a thermally conductive heat plate having a first end portion for contacting first terminal and second end portion for contacting second terminal, a first electrically insulative film encapsulating the first end portion, and a second electrically insulative film encapsulating the second end portion.

A contactor includes a housing defining a cavity. The contactor includes a switch assembly received in the cavity. The switch assembly includes first and second fixed contacts received in the cavity and a movable contact movable within the cavity between a mated position and an unmated position. The movable contact engages the first and second fixed contacts to electrically connect the first and second fixed contacts in the mated position. The switch assembly includes a coil assembly in the cavity operated to move the movable contact between the unmated position and the mating position. The contactor includes a heat transfer device coupled to the housing. The heat transfer device is thermally coupled to the first fixed contact and the second fixed contact to dissipate heat from the first fixed contact and the second fixed contact.

A circuit breaker for an electrical device and an electrical system are provided. The circuit breaker includes a housing, at least one first busbar, at least one second busbar, a circuit board, and an actuating mechanism. The first busbar is coupled to a power supply side of the circuit breaker. The second busbar is coupled to a load side of the circuit breaker. The circuit board is arranged between the at least one first busbar and the at least one second busbar and includes an electrical component, two ends of the electrical component are respectively coupled to the first busbar and the second busbar, and the electrical component is adapted to act during occurrence of a line abnormality to cut off the electrical connection between the first busbar and the second busbar. The actuating mechanism is arranged between the first busbar and the power supply side of the circuit breaker.

The exemplary systems, methods, and devices of the present disclosure include a dual actuation mechanical switch for a circuit breaker that includes a piezoelectric actuator that operates in conjunction with a second mechanical actuator, e.g., for a fast, compact, lightweight, and efficient DC hybrid circuit breaker. In some implementations, the exemplary dual mechanical switch can serve as the only current carrying path of the circuit breaker to minimize on-state power loss during normal operation. The exemplary system, method, and devices can facilitate needs of the emerging DC grid.