An installation switching device includes a housing having a terminal connecting area and a screwless spring-loaded terminal fixed in position in the terminal connecting area, and a spring operating lever. The screwless spring-loaded terminal includes a clamping spring having a contact limb, a clamping limb having a clamping window with a clamping edge, and a curved spring rear connecting the contact and clamping limbs and configured to interact with a mount part surrounding a clamping strip, such that a connecting conductor is clampable between a rear face of the clamping strip and the clamping edge.