Interrupting Chamber Having Two Compression Chambers

A current-interrupting chamber designed to be used in a circuit-breaker, said current-interrupting chamber being filled with a dielectric fluid and including:

• a moving assembly mounted to move axially between a position at the start of a circuit-breaker opening operation and a position at the end of a circuit-breaker opening operation, said moving assembly comprising:
• a) at least one first compression chamber whose volume decreases between the position at the start of a circuit-breaker opening operation and a position at the end of compression of the first chamber;
• b) at least one first arcing contact designed to co-operate with a second arcing contact, the two arcing contacts being mounted to move axially relative to each other;
• and
• c) at least one second compression chamber, communicating at a first end with the first compression chamber, the volume of said second compression chamber decreasing between the position at the start of a circuit-breaker opening operation and the position at the end of a circuit-breaker opening operation, said second compression chamber being designed to inject dielectric fluid into the first compression chamber, between a position in which the first chamber is open and the position at the end of the circuit-breaker opening operation, when the pressure in the first compression chamber is lower than the pressure in the second compression chamber,
• the position at the end of compression of the first chamber is reached before the position at the end of the circuit-breaker opening operation, and a position at the end of compression of the second chamber is reached after the position at the end of compression of the first chamber.