Ac-powered contactors are extensively used in industry in applications such as automatic electrical devices, motor starters, and heaters. In this work, a practical session that allows students to model and simulate the dynamic behavior of ac-powered electromechanical contactors is presented. Simulation is carried out using a rigorous parametric model of the ac contactor that avoids simplification assumptions and is thoroughly explained. The goal of this practical is to introduce students to the topic of dynamic simulation of real devices. It covers both the transient and the steady-state response of the electromechanical system under study. The proposed methodology is flexible and not particularly time-consuming, and it allows the students easily to change the electromechanical constants of the contactor they are studying. The results of the simulations were compared with experimental data acquired by the students; a close similarity between real and simulated data was observed. The Technical University of Catalonia (UPC), Spain, has incorporated the simulation methodology proposed in this paper in a practical session of an electrical engineering course. (Contains 12 figures.)