Electrical circuit module with sequentially actuated contact apparatus

Plug-in circuit module for insertion into a building frame, said module comprising first movable contact device connected to a plurality of first low voltage and low current circuits, a second movable contact device connected to a plurality of second relatively high current and high voltage circuits, a front plate having a plurality of mounting screws for connecting the unit to a building frame, first mechanical connecting means for connecting said first movable contact device to said front plate, second mechanical connecting means for connecting said second movable contact device to said front plate, the play of said second mechanical connecting means in a direction perpendicular to said front plate, being greater than the play of said first mechanical connecting means in the same direction, said first movable contact device comprising a plurality of first contact parts, said second contact device comprising a plurality of second contact parts mounted in an elongated supporting body therefor, said second mechanical connecting means comprising two elongated members of variable length, which are fixed to said elongated supporting body and directed perpendicularly to said front plate, each of said elongated members comprising two parallel elongated parts which are arranged, within a limited range of movement, with mutual freedom of movement in the longitudinal direction of the member, said range of movement being limited in such a way that the minimum length of each of said members occurs when said front plate is attached to a building frame and said second movable contact device is in a correct contact position, whereas the maximum length of each of said members occurs when said front plate is withdrawn from its attached position, whereby said first movable contact devices are withdrawn at least partially, before said second movable contact devices are withdrawn at all.