An electrical circuit breaker assembly, and a method for its operation, including a conductive element of an electrical circuit and a cut-off device configured to be activated by a pyrotechnic element and that is configured to sever the conductive element in a cut-off zone delimited by a downstream point. The electrical circuit breaker assembly further includes a contactor element configured to be activated by a pyrotechnic element, the contactor element being configured to connect the downstream point of the cut-off zone to an earth conductor of the electrical circuit prior to a severing of the conductive element or simultaneously with the severing of the conductive element.