Low-voltage multipolar circuit breaker

A low-voltage multipolar circuit breaker, comprising a moulded housing including a main body and a cover, the cover being mounted on the main body and covering a main face of the main body, the main body being divided into interior compartments, each associated with one pole of the circuit breaker;

• the circuit breaker further comprising, for each pole, inside a corresponding compartment:
• electrical contacts that can be separated with a switching mechanism of the circuit breaker;
• an arc-extinguishing chamber comprising:
• a stack of arc-separation plates, a spark guard which tops the stack, and an extinguishing gas outlet aperture, provided with a filtering device;
• the circuit breaker, wherein for at least two of the poles, the main face of the main body includes an additional aperture placed directly above the spark guard of a corresponding pole of the at least two poles and placing the arc-extinguishing chamber of the corresponding pole in fluid communication with an interior volume formed between the cover and the main face,
• and wherein the cover is attached to the main body while leaving a peripheral opening between the cover and the main body over an entire perimeter of the cover, the peripheral opening placing the interior volume in fluid communication with an exterior of the housing.