An installation switching apparatus includes: a housing; at least one contact point; an exhaust air duct which in an upstream portion thereof receives arc gases of a switching arc that has been created at the at least one contact point, and by way of an exhaust air opening in a housing wall of the housing in a downstream portion of the exhaust air duct the exhaust air duct releases the arc gases into an environment of the housing; at least one thermal release; and a set screw for setting the at least one thermal release. The set screw at an activation end thereof has a formed element for contacting in a form-fitting manner a tool for rotating activation of the set screw. An operative end of the set screw is coupled to the at least one thermal release.

A device for joining a bimetal strip and a component that acts as a support for the bimetal strip in a current breaking unit, the bimetal strip being electrically connected by a free end, to a input connection area, and by another end, by way of which the bimetal strip is fixed to the support, to a output connection area. The bimetal strip is mounted to pass through the support to be fixed at different locations along the length of the bimetal strip, the bimetal strip having a first part and a second part that are situated respectively on one side and the other of the support, the first part being on the side of the free end, corresponding to the usable surface of the bimetal strip, the length of the usable surface being variable depending on the insertion length of the bimetal strip in the support, the insertion length being determined depending on the calibre of the unit to obtain a constant thermal profile, regardless of the calibre, and to an electrical protection unit with same.

A device for joining a bimetal strip and a component that acts as a support for the bimetal strip in a current breaking unit, the bimetal strip being electrically connected by a free end, to a input connection area, and by another end, by way of which the bimetal strip is fixed to the support, to a output connection area. The bimetal strip is mounted to pass through the support to be fixed at different locations along the length of the bimetal strip, the bimetal strip having a first part and a second part that are situated respectively on one side and the other of the support, the first part being on the side of the free end, corresponding to the usable surface of the bimetal strip, the length of the usable surface being variable depending on the insertion length of the bimetal strip in the support, the insertion length being determined depending on the calibre of the unit to obtain a constant thermal profile, regardless of the calibre, and to an electrical protection unit with same.