A reversible circuit breaker that protects an electrical circuit by interrupting a circuit break assembly between an A-side terminal and a B-side terminal when a fault condition is detected, the reversible circuit breaker including an electronics package that assists in the detection of fault conditions, the electronics package having a power connection, the reversible circuit breaker comprising: a power source selection circuit (326, 610), including: an A-side power path that electrically couples the A-side terminal to the power connection of the electronics package; a B-side power path that electrically couples the B-side terminal to the power connection of the electronics package, an A-side path interrupter that is interposed in the A-side power path between the A-side terminal and the power connection of the electronics package; and an B-side path interrupter that is interposed in the B-side power path between the B-side terminal and the power connection of the electronics package; an A-side interruption selector circuit and a B-side interruption selector circuit, each being connected via an A-side test path to the A-side terminal and via a B-side test path to the B-side terminal, wherein, when the circuit break assembly is open and the A-side power path is connected to a line side, the B-side interruption selector circuit is configured to activate or interrupt permanently the B-side path interrupter while the A-side path interrupter is deactivated or remains conductive, such as to connect the power connection via the A-side power path to the line side; and wherein, when the circuit break assembly is open and the B-side power path is connected to the line side, the A-side interruption selector circuit is configured to activate or interrupt permanently the A-side path interrupter while the B-side path interrupter is deactivated or remains conductive, such as to connect the power connection via the B-side power path to the line side. a power source selection circuit (326, 610), including: an A-side power path that electrically couples the A-side terminal to the power connection of the electronics package; a B-side power path that electrically couples the B-side terminal to the power connection of the electronics package, an A-side path interrupter that is interposed in the A-side power path between the A-side terminal and the power connection of the electronics package; and an B-side path interrupter that is interposed in the B-side power path between the B-side terminal and the power connection of the electronics package; an A-side interruption selector circuit and a B-side interruption selector circuit, each being connected via an A-side test path to the A-side terminal and via a B-side test path to the B-side terminal, an A-side power path that electrically couples the A-side terminal to the power connection of the electronics package; a B-side power path that electrically couples the B-side terminal to the power connection of the electronics package, an A-side path interrupter that is interposed in the A-side power path between the A-side terminal and the power connection of the electronics package; and an B-side path interrupter that is interposed in the B-side power path between the B-side terminal and the power connection of the electronics package; an A-side interruption selector circuit and a B-side interruption selector circuit, each being connected via an A-side test path to the A-side terminal and via a B-side test path to the B-side terminal, wherein, when the circuit break assembly is open and the A-side power path is connected to a line side, the B-side interruption selector circuit is configured to activate or interrupt permanently the B-side path interrupter while the A-side path interrupter is deactivated or remains conductive, such as to connect the power connection via the A-side power path to the line side; and wherein, when the circuit break assembly is open and the B-side power path is connected to the line side, the A-side interruption selector circuit is configured to activate or interrupt permanently the A-side path interrupter while the B-side path interrupter is deactivated or remains conductive, such as to connect the power connection via the B-side power path to the line side.