Systems and methods for tripping open circuit interrupters based on the detection of an arc flash using an accessory arc flash detection module are disclosed. The housing of the arc flash detection module is structured to be installed within the frame of a circuit interrupter. The detection module communicates with light sensors structured to detect light from arc flash events, and includes a controller configured to communicate with an electronic trip unit of the circuit interrupter. In one embodiment, the detection module is configured to alert the electronic trip unit that light indicative of arc flash conditions has been detected such that the electronic trip unit can determine whether or not to initiate a trip after determining the magnitude of current flowing through the circuit interrupter. In another embodiment, the detection module is configured to directly actuate a trip of the circuit interrupter based on the detection of light.

A selective protection circuit includes a current-limiting module and a control module, where the current-limiting module includes a switch unit, and the switch unit includes a first end, a second end, and a control end; the first end is connected to a positive electrode of a bus voltage of an HVDC power supply, and the second end is connected to a positive electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting module; the control end is connected to the control module; and the control module is configured to output a control signal to the control end when a value of a total current flowing through the switch unit is greater than or equal to a preset threshold, so as to switch off the switch unit.

A selective protection circuit includes a current-limiting module and a control module, where the current-limiting module includes a switch unit, and the switch unit includes a first end, a second end, and a control end; the first end is connected to a positive electrode of a bus voltage of an HVDC power supply, and the second end is connected to a positive electrode of a power supply of a voltage pre-regulator circuit in a load branch connected to the current-limiting module; the control end is connected to the control module; and the control module is configured to output a control signal to the control end when a value of a total current flowing through the switch unit is greater than or equal to a preset threshold, so as to switch off the switch unit.

A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.

A gas circuit breaker includes a sealed tank, a movable side main electrode and a fixed side main electrode in the sealed tank facing each other, a movable side arc electrode and a fixed side arc electrode in the sealed tank facing each other, a cylinder at a circumference of the movable side arc electrode, a piston in the cylinder in a slidable manner and forming a puffer chamber together with the cylinder, an insulation nozzle in the sealed tank, an exhaust pipe at a circumference of the fixed side arc electrode and exhausting heat gas, which is sprayed on an arc generated in the insulation nozzle in the opening electrode operation, to an outside, and a closing plate in the exhaust pipe. One or more vent holes leading the heat gas from an inside of the exhaust pipe to the outside is on a surface of the closing plate.

An arc extinguishing unit and an air circuit breaker comprising same are disclosed. The arc extinguishing unit according to an embodiment of the present disclosure comprises an arc extinguishing magnet located above a grid. The arc extinguishing magnet forms a magnetic field in the arc extinguishing part and in a fixed contact and a movable contact that are located adjacent to the arc extinguishing part. An arc generated as the fixed contact and the movable contact are separated from each other receives an electromagnetic force in the formed magnetic field. The electromagnetic force passes through the grid and is formed in a direction facing the exterior of the arc extinguishing part. Thus, the generated arc may be quickly extinguished and moved.

An electric arc breaker device comprises a contact zone in which there are present at least one stationary contact and at least one movable contact that is movable relative to the stationary contact. The contacts are capable of being put into contact with each other and of being separated from each other. An arcing horn is present facing the stationary contact, the height h.sub.c of the arcing horn being greater than or equal to the height h.sub.t of the stationary contact, and the arcing horn presenting a folded-back arc switching portion extending in a direction away from the stationary contact.

An electrical apparatus for breaking an electric current includes an electrical arc extinguishing chamber, for extinguishing an electrical arc formed on the separation of electric contacts, provided with an extinguishing gas exhaust orifice and an extinguishing gas filtration system, placed at the output of the exhaust orifice and including a filter and a gas diffusor. The gas diffuser includes, superposed between them, a central layer and two outer layers arranged on either side of the central layer. The central layer is provided with first through holes. Each outer layer is provided with second through holes. The first holes are misaligned relative to the second holes so that each of the second holes emerges on a solid portion of the central layer without any first hole.

A shield apparatus and a resultant circuit interrupter are disclosed, wherein the shield apparatus includes a shield apparatus base and a protection apparatus, with the protection apparatus including a shield that helps to direct an electrical arc along a flow path through a number of passages and that will help to enable dissipation of the arc and the plasma generated thereby. The shield apparatus is mountable to a portion of the housing of the circuit interrupter within its interior, and the shield is situated adjacent at least a first passage.

A shield apparatus and a resultant circuit interrupter are disclosed, wherein the shield apparatus includes a shield apparatus base and a protection apparatus, with the protection apparatus including a shield that helps to direct an electrical arc along a flow path through a number of passages and that will help to enable dissipation of the arc and the plasma generated thereby. The shield apparatus is mountable to a portion of the housing of the circuit interrupter within its interior, and the shield is situated adjacent at least a first passage.