Dc circuit breaker

A DC circuit breaker comprising:

• a case formed of an electrically insulative material;
• two fixed contacts fixed within the case;
• two movable contacts each provided so as to correspond to each of the two fixed contacts;
• a bypass plate having the two movable contacts fixed thereto and electrically connecting the two movable contacts;
• a moving block having a groove in which the bypass plate is disposed and being provided so as to be movable in a direction to move away from the fixed contacts within the case, the moving block being configured to move the bypass plate in a direction to move away from the fixed contacts when moving in the direction to move away from the fixed contacts;
• a moving block biasing member configured to constantly bias the moving block in the direction to move away from the fixed contacts;
• a thermally responsive member provided in a position opposing an installation surface and configured to deform when the installation surface becomes equal to or greater than a prescribed temperature;
• a latch having a locking portion configured to restrict movement of the moving block by locking the moving block when the thermally responsive member is in a pre-deformation state, the latch being configured to operate to cancel the restriction of the movement of the moving block by unlocking the locking portion from the moving block in response to a deformation of the thermally responsive member;
• a shutter formed of an electrically insulative material and configured to be inserted between the fixed contacts and the movable contacts when the movable contacts are separated from the fixed contacts;
• and
• a shutter biasing member configured to constantly bias the shutter in a direction to be inserted between the fixed contacts and the movable contacts.