Circuit breaking unit and air circuit breaker including same

A circuit breaking unit, comprising:

• 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 on which the movable contact is disposed and configured such that the movable contact moves 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 magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field so that a generated arc is subjected to an electromagnetic force to the left or right.

A air circuit breaker, comprising:

• a cover;
• an arc extinguishing unit disposed within the cover and comprising a plurality of side plates and a grid coupled between the side plates;
• and
• a circuit breaking unit disposed adjacent to the arc extinguishing unit, wherein the circuit breaking unit comprises:
• 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 on which the movable contact is disposed and configured such that the movable contact moves 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 U assembly disposed between the low runner and the fixed contact terminal, extending away from the fixed contact terminal and extending toward the movable contact,
• wherein the U assembly is formed to extend to opposite sides so that when an arc is generated, the pressure applied to the arc is increased.

A air circuit breaker, comprising:

• a cover;
• an arc extinguishing unit disposed within the cover and comprising a plurality of side plates and a grid coupled between the side plates;
• and
• a circuit breaking unit disposed adjacent to the arc extinguishing unit,
• wherein the circuit breaking unit comprises:
• 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 on which the movable contact is disposed and configured such that the movable contact moves 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 magnet unit disposed between the low runner and the fixed contact terminal and forming a magnetic field so that a generated arc is subjected to an electromagnetic force to the left or right.