Circuit Beakers and Switches mechanism model requirements Michel ABADIE Schneider Electric - Power Business - 31 Avenue Pierre Mendès France, 38000 Grenoble, France Emmanuel Frangin Schneider Electric - Strategy & Innovation - 37 Quai Paul Louis Merlin, 38000 Grenoble, France Schneider Electric is designing and producing robust circuit breakers and switches to protect customers and installation against electrical risks. At the heart of our products, we have mechanisms which are in charge to open and close electrical contacts, with a contact force up to 15000N, using an order of less than 15N given by actuators or by the user. This presentation will show what are the main contact problems we are addressing during the design of mechanisms and how we treat them using simulations and tests. We will especially focus on tripping force, closing security, closing velocity and contact bouncing. We will end this presentation by presenting progress axis we are working on to improve our simulation capabilities like clearance in joints to predict tilting effects.