Circuit Breakers in Electrical Engineering it plays a vital role. It is not only used to protect the circuit from overload and short circuit, but also to effectively control the operation of electrical equipment. This article will explore the basic concepts, working principles, types and application scenarios of circuit breakers and other related knowledge to help readers better understand and apply this key equipment.

Basic concepts

circuit Breaker(Circuit Breaker) is a kind of electrical equipment, mainly used to protect the circuit from damage caused by overload and short circuit. It is the control switch of the circuit, which can quickly cut off the circuit when the current is abnormal to prevent equipment damage, fire or other safety accidents. Circuit breakers are usually divided into two categories: low-voltage circuit breakers and high-voltage circuit breakers, which are used in various electrical systems.

Working principle

the working principle of the circuit breaker is based on two mechanisms: heat release and magnetic field release:

• heat release: When the current in the circuit exceeds the rated current of the circuit breaker, the thermal element inside the circuit breaker (such as a thermal release magnet or a bimetal strip) will generate a thermal effect to cause the trigger mechanism to act and quickly cut off the circuit.

• magnetic field release: When a large current (such as a short-circuit current) occurs in the circuit, the magnetic field release device inside the circuit breaker will sense a change in the magnetic field, which will cause the trigger mechanism to act and realize a fast circuit breaker.

Type

circuit breakers can be divided into many types according to different usage scenarios and rated voltage levels:

1. classification by use:

   • low voltage circuit breaker: Suitable for household, commercial and light industrial power systems, the rated voltage is usually below 1000V.
   • high voltage circuit breaker: Mainly used in industrial and power systems, the rated voltage can reach tens of kilovolts, used to protect high-power equipment and high-voltage circuits.

2. Classification by breaking capacity:

   • fixed circuit breaker: Has a fixed open circuit capability and cannot be adjusted.
   • adjustable circuit breaker: The breaking capacity can be adjusted according to actual needs to adapt to different circuit conditions and load requirements.

3. Classification by operation mode:

   • manually Operated Circuit Breaker manual intervention is required for switch operation.
   • automatically operated circuit breaker: Able to automatically judge and disconnect the circuit according to preset conditions.

Application Scenarios

circuit breakers are widely used in various electrical systems, including but not limited:

• home and Commercial Buildings: Used to protect circuit equipment inside homes and commercial buildings, such as lighting, sockets, etc.
• Industrial Manufacturing: Protect the factory and manufacturing equipment to prevent damage caused by equipment overload or short circuit.
• electric power system: Used to protect generators, transformers and transmission lines in the power transmission and distribution network to ensure the safe and stable operation of the power system.

Introduction of Special Type Circuit Breaker

1. air circuit breaker(Air Circuit Breaker, ACB):

   • use air as arc extinguishing medium, suitable for low and medium voltage electrical systems.
   • It has good arc extinguishing performance and high short-circuit breaking ability, and is usually used in industrial and commercial applications.

2. Vacuum circuit breaker(Vacuum Circuit Breaker, VCB):

   • use vacuum as arc extinguishing medium, suitable for medium and high voltage electrical systems.
   • With the advantages of fast action, high reliability and low maintenance cost, it is widely used in power system.

3. oil immersed circuit breaker(Oil Circuit Breaker):

   • using insulating oil as an arc extinguishing medium, it is mainly used in high voltage electrical systems.
   • With good arc extinguishing and isolation performance, it is suitable for power equipment that requires high reliability and safety.

As an indispensable protection device in electrical system, the correct selection and application of circuit breaker is very important to ensure the safe operation of circuit and equipment. Through the introduction of this article, readers can have a deeper understanding of the working principle, types and application scenarios of circuit breakers, and provide reference and guidance for practical engineering applications to ensure the safety, reliability and efficiency of electrical systems.