circuit breaker
"Air breaker" usually refers to an "air circuit breaker", which is a switching device used to protect circuits and electrical equipment. The following is a detailed introduction about it:
Working Principle
The air circuit breaker uses air as the arc extinguishing medium. When faults such as overload, short circuit, or undervoltage occur in the circuit, the tripping mechanism inside the circuit breaker will act, causing the contacts to separate and cutting off the circuit. At the moment when the contacts separate, an arc will be generated. The air circuit breaker, through the special design in the arc extinguishing chamber, such as stretching the arc and cooling the arc, can quickly extinguish the arc in the air, thus achieving the protection of the circuit.
Structural Composition
- **Contact System**: It is used to connect and disconnect the circuit. It is usually composed of moving contacts and stationary contacts, and is made of materials with good electrical conductivity.
- **Arc Extinguishing System**: It is the key part of the air circuit breaker. Generally, it includes components such as the arc extinguishing chamber and the arc extinguishing grid, which can quickly and effectively extinguish the arc, preventing the arc from reigniting and inter-phase short circuits.
- **Tripping Mechanism**: When a fault occurs in the circuit, the tripping mechanism will cause the circuit breaker to trip and cut off the circuit within the specified time according to the type of fault (such as overload, short circuit, etc.). Common trip devices include thermal trip devices, electromagnetic trip devices, and compound trip devices, etc.
- **Operating Mechanism**: It is used to control the closing and opening operations of the circuit breaker. It can be manually operated, or electrically operated, and can also cooperate with remote control devices to achieve remote operation.
Characteristics
- **Strong Arc Extinguishing Ability**: It can extinguish the arc within a short time, effectively protecting the circuit and equipment.
- **High Breaking Capacity**: It can withstand a relatively high short-circuit current, and the breaking capacity is usually between several thousand amperes and several tens of thousand amperes.
- **Complete Protection Functions**: It has a variety of functions such as overload protection, short-circuit protection, and undervoltage protection, which can meet the protection requirements of different circuits.
- **Long Service Life**: Under normal use conditions, both the mechanical life and the electrical life of the air circuit breaker are relatively long, reducing the frequency and cost of equipment replacement.
- **Convenient Maintenance**: The structure is relatively simple, and the maintenance and repair are relatively easy, without the need for special maintenance equipment and technology.
Application Scenarios
- **Industrial Field**: Widely used in the power distribution systems of factories, motor control centers, etc., to protect various electrical equipment such as transformers, motors, switchgear, etc., and prevent equipment damage and safety accidents caused by circuit faults.
- **Commercial Buildings**: In the electrical systems of commercial places such as office buildings, shopping malls, and hotels, the air circuit breaker is an important protection device, used to ensure the reliability and safety of power supply and protect electrical equipment such as lighting, air conditioning, and elevators.
- **Residential Field**: Small air circuit breakers are also used in household distribution boxes to protect household electrical appliances from overload and short circuits, ensuring the safety of residents' electricity use.
- **Power System**: In power systems such as substations and switchgear rooms, the air circuit breaker, as an important switching device, is used to control and protect power lines and equipment, ensuring the stable operation of the power system.
