Component assembly system having a profiled carrier rail, comprising: a functional component; a bridge module for electrically connecting a functional component, which bridge module comprises a module retaining device for retaining the bridge module on the profiled carrier rail; wherein the functional component is designed to be partially placed on the bridge module, and wherein the functional component comprises a component retaining device for retaining the functional component on the profiled carrier rail, wherein the module retaining device is designed to establish a latching connection between the bridge module and the profiled carrier rail, characterized in that the functional component can be placed onto the bridge module, wherein the module retaining device can be covered by a housing edge of the functional component and thereby can be arrested or blocked to prevent release; and wherein the component retaining device comprises a latching slide for releasably fastening the functional component to the profiled carrier rail, wherein the latching slide is designed to engage around the profiled carrier rail with a form fit, wherein the latching slide can be displaced into a pushed-forward arresting position for engaging below the functional component on the profiled carrier rail, and wherein the latching slide can be displaced into a pulled-back release position for placing the functional component onto the profiled carrier rail, and wherein the latching slide comprises a latching arm for latching the latching slide in the arresting position and for latching the latching slide in the release position, wherein the latching slide has a fastening protrusion which engages behind the profiled carrier rail such that a form fit is established, and the latching arm is designed such that it engages in a first latching opening or in a second latching opening of the functional component, depending on the position. a functional component; a bridge module for electrically connecting a functional component, which bridge module comprises a module retaining device for retaining the bridge module on the profiled carrier rail; wherein the functional component is designed to be partially placed on the bridge module, and wherein the functional component comprises a component retaining device for retaining the functional component on the profiled carrier rail, wherein the module retaining device is designed to establish a latching connection between the bridge module and the profiled carrier rail, characterized in that the functional component can be placed onto the bridge module, wherein the module retaining device can be covered by a housing edge of the functional component and thereby can be arrested or blocked to prevent release; and wherein the component retaining device comprises a latching slide for releasably fastening the functional component to the profiled carrier rail, wherein the latching slide is designed to engage around the profiled carrier rail with a form fit, wherein the latching slide can be displaced into a pushed-forward arresting position for engaging below the functional component on the profiled carrier rail, and wherein the latching slide can be displaced into a pulled-back release position for placing the functional component onto the profiled carrier rail, and wherein the latching slide comprises a latching arm for latching the latching slide in the arresting position and for latching the latching slide in the release position, wherein the latching slide has a fastening protrusion which engages behind the profiled carrier rail such that a form fit is established, and the latching arm is designed such that it engages in a first latching opening or in a second latching opening of the functional component, depending on the position.