The invention relates to an electrical power supply switch for a protection module and a protection module comprising such a switch. The electrical power supply disconnector (50) is used for establishing or severing the connection between current conductors and a power supply circuit. The electrical power supply disconnector (50) includes a housing including a central passage (11), the walls (12,13) of which bear contact strips (21, 22, 23, 24) that are located facing one another along a contact axis (Y), and a slider (1) sliding through the central passage (11) in the direction of a centre axis (X), and bearing at least a first electrically conductive bar (2), oriented along the contact axis (Y), for electrically connecting at least one first low contact strip (21) and one high contact strip (22) when the slider (1) is in a first position.