Air circuit breaker having an improved electric arc quenching chamber

An air circuit breaker, comprising:

• two separable electrical contacts connected to electric current input and output terminals;
• and
• a chamber for quenching an electric arc, to extinguish the electric arc formed during the separation of the electrical contacts, said quenching chamber comprising a stack of splitter plates that are spaced apart from one another, and lateral walls placed on either side of the stack, the splitter plates being fixed to the lateral walls, each lateral wall including a thermosetting-resin impregnated polyamide fabric and being devoid of glass fibres,
• wherein the quenching chamber furthermore includes protective elements made of crosslinked polyamide, said protective elements being placed inside the quenching chamber, along the lateral walls on either side of the stack, in junction zones between the lateral walls and the splitter plates, the protective elements covering corners of the splitter plates which corners are adjacent to the lateral walls, so as to separate these corners of the splitter plates from the electrical contacts, and
• wherein each protective element has a curved lateral surface extending, with a concave shape, from the lateral wall adjacent to the protective element to a central region of the stack.

An air circuit breaker, comprising:

• two separable electrical contacts connected to electric current input and output terminals;
• and
• a chamber for quenching an electric arc, to extinguish the electric arc formed during the separation of the electrical contacts, said quenching chamber comprising a stack of splitter plates that are spaced apart from one another, and lateral walls placed on either side of the stack, the splitter plates being fixed to the lateral walls, each lateral wall including a thermosetting-resin impregnated polyamide fabric and being devoid of glass fibres,
• wherein the quenching chamber furthermore includes protective elements made of crosslinked polyamide, said protective elements being placed inside the quenching chamber, along the lateral walls on either side of the stack, in junction zones between the lateral walls and the splitter plates, the protective elements covering corners of the splitter plates which corners are adjacent to the lateral walls, so as to separate these corners of the splitter plates from the electrical contacts, and
• wherein the protective elements of crosslinked polyamide each contain a mineral material with a concentration by weight less than or equal to 40%, the mineral material being other than glass fibres.