This paper deals with the effect of electrodynamic forces acting on the primary current paths of residual current circuit breakers. This paper consists of a simulation part and an experimental part from the short-circuit tests performed. The experimental part presents short-circuit tests and shows the occurrence of electrodynamic forces in a visible way. The formation of electrodynamic forces in the current paths of residual current circuit breakers is associated with the flow of large currents but primarily with short-circuit currents. To highlight this phenomenon, a detailed specification of the parameters during the tests was presented. In the simulation part, the physical phenomenon of electrodynamic forces was captured by using a detailed 3D model of residual current circuit breakers and real-scale current paths. Accordingly, the authors proposed a new method using finite element analysis to obtain the values of electrodynamic forces acting on the current paths of the residual current circuit breaker by performing a detailed 3D-coupled simulation. The analysis of the obtained results and the subsequent effects of their interactions provided interesting conclusions, allowing us to improve the circuit breaker design to withstand critical short-circuit conditions.