A breaker device (1; 100; 111) for connecting to an electrical circuit, the device comprising at least one pyrotechnic initiator and a body (11; 114) having present therein: - a pressurizing chamber in communication with an outlet from said pyrotechnic initiator and constituting a first breaker device chamber; - at least one electrically conductive portion (8; 180) for connection to the electrical circuit, at least a fraction of the conductive portion (8; 180) being present in a second chamber that is present in the body (11; 114); - at least one fusible element (40; 130) connected in series with the conductive portion, the initiator being connected to the terminals of said fusible element and said fusible element being configured to trip when the current passing through it exceeds a predetermined value, thereby actuating the initiator; and - a movable breaker element separating the first chamber from the second chamber and presenting at least one projecting portion made of electrically insulating material, said at least one projecting portion facing the conductive portion (8; 180); the pyrotechnic initiator being configured to cause the breaker device to pass from a current-passing first configuration to a circuit-breaking second configuration, the breaker device being characterized in that the movable breaker element is moved towards the conductive portion in order to break it by impact against the projecting portion in a zone that is distinct from the zone where the fusible element is present on passing from the first configuration to the second, the fusible element being present either in the second chamber and being connected with its insulating shell to the conductive portion, or in a third chamber distinct from the second chamber wherein a powder of electrically insulating material also being present in the third chamber. - a pressurizing chamber in communication with an outlet from said pyrotechnic initiator and constituting a first breaker device chamber; - at least one electrically conductive portion (8; 180) for connection to the electrical circuit, at least a fraction of the conductive portion (8; 180) being present in a second chamber that is present in the body (11; 114); - at least one fusible element (40; 130) connected in series with the conductive portion, the initiator being connected to the terminals of said fusible element and said fusible element being configured to trip when the current passing through it exceeds a predetermined value, thereby actuating the initiator; and - a movable breaker element separating the first chamber from the second chamber and presenting at least one projecting portion made of electrically insulating material, said at least one projecting portion facing the conductive portion (8; 180); the pyrotechnic initiator being configured to cause the breaker device to pass from a current-passing first configuration to a circuit-breaking second configuration, the breaker device being characterized in that the movable breaker element is moved towards the conductive portion in order to break it by impact against the projecting portion in a zone that is distinct from the zone where the fusible element is present on passing from the first configuration to the second, the fusible element being present either in the second chamber and being connected with its insulating shell to the conductive portion, or in a third chamber distinct from the second chamber wherein a powder of electrically insulating material also being present in the third chamber.