Exemplary embodiments are directed to a controller unit for a switching device. The controller unit includes a body part and an operating axle, which is turnable between a closed position and an open position in relation to the body part and is functionally connectable to contacts of the switching device to change respective states of the contacts between the closed position and the open position. The controller also includes a control axle that is turned by a user between an off-position and an on-position in relation to the body part and is functionally connected to turn the operating axle. A tripping assembly is functionally connected to the operating axle such that the tripping event of the tripping assembly turns the operating axle from the closed position to the open position. Connecting means selectably connect the control axle to the tripping assembly.