Structure and application of the air circuit breaker (ACB)

The air circuit breaker ACB is a device used for switching and protecting the overload and short circuit.

In this article, Hao Phuong will tell you about the structure and use of the air circuit breaker ACB.

Structure of the ACB

Contact Mechanism

Electric conductors are modularly designed. Each pole consists of main contacts and arc contacts. These contacts are installed in modular enclosures and are made of silver alloys. The operation of the contact mechanism is the arc contacts. The contacts will close first and open after the main contacts. This reduces the corrosion of the main contacts.

cấu tạo máy cắt không khí acb

Arc stamping compartment (Arc Chutes)

the arc stamping compartments are provided for stamping electric arc. This unit consists of thin metal plates installed in parallel in isolation covers. The arc is evenly distributed to these metal plates. Arc is therefore limited, split and quenched in arc stamping parts. Reasonable isolation between conductive parts, less energy consumption. When a short circuit makes it possible to set up the load connections and power supply systems on both sides.

Release mechanism

The release mechanism consists of magnetic latches that link to the release press buttons. The circuit provides a signal for this part. In the case of overcurrent, overload …this part will work to release the breaker.

Application of the air circuit breaker (ACB)

ACB distributes electricity or is used to protect electric motors. In alternating current, the capacity of the breaker is 200 – 4000A.

Protection feature of ACB

Protection feature has two types: one is non-selective and one is selective. Selective protection uses three characteristics such as immediate effects, short-term effects and long-term effects.

Because many of the jumping mechanisms are combined, ACB can form various protective characteristics. So they are used in branch segments close to the power source or at the end of the branch segment.

For the type of air circuit breaker ACB used to protect the motor in general. Using AC 60- 600A type can directly start. The advantage of the direct starting method is that it can protect the motor of the vibrating cage. As for the indirect method of starting, the protection of the induction motor rotor and the vibrating cage is protected.