Limiting circuit breaker

A limiting circuit breaker with high-speed contact opening control by Thomson effect, comprising, per pole, a movable assembly having a movable main contact bridge forming a main circuit with a pair of stationary main contacts connected to current terminals, a movable arcing contact bridge forming with a pair of stationary arcing contacts an arcing circuit connected in parallel to the main circuit, a movable assembly operating mechanism, for opening the main circuit and the arcing circuit, comprising a Thomson effect propelling part, a locking device of the movable assembly in the open position of the contacts and an unlocking control device, the main contact bridge being disposed between the stationary main contacts and the Thomson effect propelling part, the movable assembly comprising an operating rod securedly united to the main contact bridge, the Thomson effect propelling part comprising an annular opening coil surrounding said rod, an opening disk disposed facing the opening coil and movable in relation to said rod, and an annular piston securedly united to the operating rod, springs being disposed between the disk and the piston, in such a way that a current supply to the opening coil causes repulsion of the disk and of the piston and movement of the operating rod to the open position of the contacts, said springs returning the disk to the rest position facing the coil at the end of the opening travel.