An electrical installation includes a circuit-breaker having a breaking capacity PdC and a tripping current Is, an ammeter measuring the current, and a DC voltage source comprising batteries connected in parallel and connected in series with the circuit-breaker. The sum of the short-circuit currents of the batteries connected in parallel is higher than the breaking capacity PdC of the circuit-breaker. A plurality of the batteries each includes a respective switch capable of opening a connection between the battery of the same and the circuit-breaker. The electrical installation also includes a control circuit to detect that the current passing through the circuit-breaker is higher than the tripping current Is and to control the opening of a plurality of the switches in order to apply, through the circuit-breaker, a current higher than the tripping current Is of the same and lower than the breaking capacity PdC of the same.