An electrical cut-off device (1) with a single cut-off which comprises fuse boxes (5) that are each provided with a fuse (50) connected in series with the single cut-off element. The fuse box is a separate element mounted onto the electrical cut-off device and comprises a handle (55) that is movable, relative to the electrical cut-off device, into a passive position where the fuse box is connected to the electrical cut-off device but not locked, the electrical cut-off device being in an open position, an active position wherein the fuse box is connected and locked to the electrical cut-off device, the electrical cut-off device is switchable between open and closed positions and an intermediate position where the fuse box is partially removed from the electrical cut-off device and forms a disconnected position. The electrical cut-off device being able to be padlocked, in the intermediate position, so that it is isolated, and the disconnected position of the contacts being visible to the operator through the fuse box.