Abstract: A circuit breaker mechanism comprises a line terminal, a load terminal and a set of contacts between the terminals. A fixed contact is connected to the line terminal, and a moving contact is connected to the load terminal via a conductive frame and a load sensing element. The moving contact is fixed to a contact carrier which is supported pivotably on conductive pins which are electrically connected to the frame. A spring urges the contact carrier into snug engagement with the conductive pins. The arrangement obviates the need for a flexible conductive pig-tail to form a current path between the contact carrier and the frame, simplifying the construction and improving the performance of the circuit breaker. With this arrangement, the current path extends from the line terminal to the moving contact, through the contact carrier, through the conductive pins, to the conductive frame and through the load sensing element to the load terminal.