Disclosed are a circuit breaking unit and an air circuit breaker including the same. The present disclosure provides a circuit breaking unit, including a fixed contact; a movable contact that is in contact with or spaced apart from the fixed contact; a fixed contact terminal having the fixed contact disposed at a lower end thereof and extending upward; a movable contact terminal including the movable contact and configured such that the movable contact is formed to move in a direction toward the fixed contact or in a direction away from the fixed contact; a low runner disposed extending upward from the fixed contact, one end thereof coupled to the fixed contact terminal, and the other end thereof spaced apart from the fixed contact terminal; and a protruding contact disposed extending upward from the movable contact, energized when in contact with the low runner, and spaced apart from the low runner when the movable contact is tripped.

The present invention relates to an arc ventilation system of a multi-stage distributing board, and more particularly, to an arc ventilation system of a multi-stage distributing board having an arc ventilation detour path, capable of preventing an arc generated in a lower compartment from damaging an upper compartment. The arc ventilation system of a multi-stage distributing board according to an embodiment of the present invention includes a first compartment provided at a first stage of an enclosure of the distributing board, a second compartment provided at a second stage located above the first stage, a side arc ventilation compartment provided at one side of the first compartment and the second compartment, and a middle arc induction compartment provided between the first compartment and the second compartment and communicating with the side arc ventilation compartment.

Provided is a distribution panel. The distribution panel includes a main busbar compartment in which a main busbar is provided and which is provided as an independent space and an arc duct provided at a rear side of the main busbar compartment to discharge an arc generated in the main busbar compartment. The main busbar compartment includes a communication hole defied in one surface of the main busbar to allow the main busbar compartment to communicate with the arc duct and a relief device rotatably provided on one side of the communication hole to open or close the communication hole. The relief device is bendable in multi stages. Thus, the arc may be effectively discharged while reducing a size of the distribution panel.

A low-voltage circuit breaker comprising one or more electrical poles, each of said poles having an internal space with a contact area and an arc extinguishing area, a fixed contact assembly and a movable contact assembly being positioned in said contact area, said movable contact assembly being movable between a closed position in which it is into contact with said fixed contact assembly and an open position in which it is spaced apart from said fixed contact assembly, an arc chamber comprising a plurality of substantially parallel arc-breaking plates made of a ferromagnetic material being positioned in said arc extinguishing area. The low-voltage circuit breaker is characterized in that said arc chamber further comprises at least one arc-breaking plate which is at least partially made of a ceramic material.

A pyrotechnic disconnect comprises: a housing with at least a combustion chamber therein; a pyrotechnic charge in the combustion chamber; a busbar covering an opening of the combustion chamber, the busbar configured to be severed by activation of the pyrotechnic charge; and arc splitter plates arranged in the housing on an opposite side of the busbar from the combustion chamber.

Provided is a distribution panel. The distribution panel includes a main busbar compartment in which a main busbar is provided and which is provided as an independent space and an arc duct provided at a rear side of the main busbar compartment to discharge an arc generated in the main busbar compartment. The main busbar compartment includes a communication hole defied in one surface of the main busbar to allow the main busbar compartment to communicate with the arc duct and a relief device rotatably provided on one side of the communication hole to open or close the communication hole. The relief device is bendable in multi stages. Thus, the arc may be effectively discharged while reducing a size of the distribution panel.

An electromagnetic relay includes a case including a base, a first fixed terminal held by the base, a movable contact piece, a gas inflow space, and a gas passage. The first fixed terminal includes a first fixed contact disposed apart from the base in a first direction inside the case, a contact support portion disposed between the first fixed contact and the base and configured to support the first fixed contact, and a first extending portion extending at an angle from the contact support portion and penetrating the base in the first direction. The movable contact piece includes a first movable contact facing the first fixed contact in the first direction. The gas inflow space is formed between the base and the contact support portion inside the case. The gas passage penetrates the base in the first direction and communicates the gas inflow space with an outside of the case.

An electric arc extinguishing apparatus for a molded case circuit breaker is provided. A first set of arc splitter plates (30) directs into a first flow channel (32) a flow of gases formed during an arcing event. A second set of arc splitter plates (40) directs into a second flow channel (42) a further flow of gases formed during the arcing event. A baffle (46) establishes flow channel separation between the first and second flow channels. This arrangement provides gas flow velocity that is relatively uniform throughout the arc stack and efficiently and reliably removes heat from the hot gas flow since every arc splitter plate effectively contributes to the cooling of the gas flow. Additionally, the electric arc is efficiently blown and distributed into each of the arc splitter plate gaps, resulting in higher arc voltage and improved arc extinguishing performance.

A switchgear exhaust assembly for controlling flow of exhaust from exhaust ports of a switchgear has an enclosure that is couplable to the switchgear to substantially enclose the exhaust ports. The enclosure defines a primary exhaust chamber for receiving exhaust flowing through the exhaust ports and allowing gases of the exhaust to expand and cool down. A top wall of the enclosure has a top layer and a bottom layer defining at least one secondary exhaust chamber. The bottom layer has openings whereby exhaust in the primary exhaust chamber flows to the secondary exhaust chamber. The top and bottom layers further define one or more side openings that provide fluid communication between the secondary exhaust chamber and a space surrounding the enclosure, thereby allowing exhaust to be expelled into the space.

One or more arc gas outlet holes are formed in a trip device such that an effect of easily venting an arc gas, which flows into the trip device, to the outside through the arc gas outlet holes is provided.