Switching device for a single-phase or multiphase electrical consumer, comprising - a number of line sections (LS1, LS2, LS3) corresponding to the number of phases (P1, P2, P3), wherein each line section (LS1, LS2, LS3) comprises a first connection part, serving as input, for connection to a grid phase (L1, L2, L3) and a second connection part, serving as output, for connection to a connection phase (T1, T2, T3) of the electrical consumer; - a power module that comprises at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) per phase (P1, P2, P3), wherein the at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) is wired between the first and the second connection part (8, 9); - a bypass unit that comprises one controllable electromechanical switching element (21 1, 21 2, 21 3) with a low on-resistance per phase (P1, P2, P3), wherein the controllable electromechanical switching element (21 1, 21 2, 21 3) is wired, in parallel with the at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) of this phase (P1, P2, P3), between the first and the second connection part (8, 9); wherein - the first and the second connection part (8, 9) of a respective phase (P1, P2, P3) are arranged adjacently next to one another on one side of the power module in spatial proximity in a direction of extent, - a contact bridge of the electromechanical switching element (21 1, 21 2, 21 3), assigned to a respective phase (P1, P2, P3), of the bypass unit runs in the direction of extent in order to electrically connect the first and the second connection part (8, 9) in the switched-on state, characterized in that the switching device comprises one fan element per phase (P1, P2, P3), which fan element is mechanically attached to connection rails (2, 3) belonging to a phase (P1, P2, P3). - a number of line sections (LS1, LS2, LS3) corresponding to the number of phases (P1, P2, P3), wherein each line section (LS1, LS2, LS3) comprises a first connection part, serving as input, for connection to a grid phase (L1, L2, L3) and a second connection part, serving as output, for connection to a connection phase (T1, T2, T3) of the electrical consumer; - a power module that comprises at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) per phase (P1, P2, P3), wherein the at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) is wired between the first and the second connection part (8, 9); - a bypass unit that comprises one controllable electromechanical switching element (21 1, 21 2, 21 3) with a low on-resistance per phase (P1, P2, P3), wherein the controllable electromechanical switching element (21 1, 21 2, 21 3) is wired, in parallel with the at least one controllable semiconductor switching element (11 1, 11 2, 11 3, 12 1, 12 2, 12 3) of this phase (P1, P2, P3), between the first and the second connection part (8, 9); wherein - the first and the second connection part (8, 9) of a respective phase (P1, P2, P3) are arranged adjacently next to one another on one side of the power module in spatial proximity in a direction of extent, - a contact bridge of the electromechanical switching element (21 1, 21 2, 21 3), assigned to a respective phase (P1, P2, P3), of the bypass unit runs in the direction of extent in order to electrically connect the first and the second connection part (8, 9) in the switched-on state,