Multipole circuit breaker with modular assembly

A multipole circuit breaker, comprising:

• a molded insulating case having a base plate subdivided by spacers to form a plurality of juxtaposed compartments each having a pole, and a cover having an aperture secured onto the base plate to the close the insulating case, each pole comprising a breaking module and a trip module housed in a respective compartment, said breaking module and said trip module being secured to the base plate, each breaking module including a parallelepipedic plastic monoblock cartridge which houses at least one stationary contact, an arc extinguishing chamber and a pair of connecting strips for electrical connection to a terminal and to a respective trip module;
• a mechanical actuation module secured to said cover and including an operating mechanism and a switching bar, said operating mechanism being mounted between a pair of support plates and including a toggle device having a tripping hook and a connecting spring, the toggle device being rotatable from closed to open positions via tripping of the tripping hook and a biasing force from the connecting spring, said switching bar being comprised of insulating material and supporting a plurality of movable contacts, each being cooperable with a respective stationary contact of a breaking module, said switching bar being mechanically coupled to the toggle device;
• a latch adapted to engage the tripping hook;
• a handle coupled to said operating mechanism and passing through the aperture in the cover;
• a rotary trip bar clipped via clipping means to said cover and being rotatable to engage said latch to trip the poles of the circuit breaker via action of the trip modules, wherein a plurality of recesses are provided in the spacers of the base plate to form first bearing surfaces for the switching bar and the rotary trip bar.