Low voltage switch (low voltage circuit breaker) is also called automatic air switch or automatic air circuit breaker. It integrates control and multiple protection functions. When the line is working normally, it is used as a power switch to turn on and off the circuit. When it is turned on, it is equivalent to a section of energized wire. When the circuit has short circuit, overload and other faults, it can automatically cut off the faulty circuit. Therefore, the low-voltage switch can protect the circuit and equipment.
Definition of low-voltage electrical appliances: defined according to the size of the voltage, the rated voltage in AC must be less than 1200V, and the rated voltage in DC must be less than 1500V.
The use of low-voltage switches can make the power system run more stably and safely. The specific classification is as follows:
According to the different internal structure of the low-voltage switch, it can be divided into a disconnect switch and a grounding switch. The general control principle is controlled by a switch fuse. Depending on the isolation method, it can also be used for load switches and fuse switches. According to the different closing methods of the switch, it can also be divided into open and closed switches. In the selection process, it depends on the actual situation.
Low-voltage isolating switch is a kind of isolating switch. It is the most widely used switch in high-voltage switchgear. It plays a very important role in the establishment and safe operation of power plants.
When disconnecting the load current, the low-voltage isolation switch cannot exceed its allowable disconnection current value. Low-voltage isolating switches of general structure are not allowed to operate with load, only low-voltage isolating switches equipped with arc extinguishing chambers can allow a small amount of infrequent load operation. It is worth noting that the three-phase short-circuit current of the line where the low-voltage isolating switch is located should not exceed the specified dynamic and thermal stability values.
Low voltage isolating switch function：
1.The isolation switch can have a good insulation effect, so that the entire circuit can be safe and secure, and maintenance personnel or staff can also repair the circuit in time
2.In addition, the low-voltage isolation switch has the function of changing the circuit, and such switches are widely used in electrical factories. An example is as follows: the production line needs to change the scheduling of product specifications or models. At this time, the isolation switch can change the operation mode of the circuit by cutting off the power supply, so as to maximize the benefit of the circuit.
3.In addition to the above functions, the low-voltage isolation switch can also connect the line. In the low-voltage equipment of residential houses or general buildings, the isolation switch reduces the hidden danger of safety accidents through non-manual operation. This makes our lives more convenient and the operation of power distribution and transmission.
The grounding switch is a switch used to connect or cut off the grounding circuit of electrical equipment and power supply. Its main function is to prevent short-circuit failure or accidental power connection of electrical equipment, to protect personal safety and safe operation of electrical equipment.The specific important roles are detailed as follows:
1. System protection
In power systems, ground faults are a common phenomenon. When a ground fault occurs in the power equipment, it will lead to the reduction of the electrical performance of the equipment, and it is easy to cause serious consequences such as fire. At this time, the grounding switch can quickly cut off the grounding circuit, so as to avoid the expansion of faults and protect the safe operation of electric equipment.
2. Personal safety protection
When leakage occurs in the casing of electrical equipment, the grounding circuit is a very dangerous path that can cause accidents such as personal injury or death. The grounding switch can cut off the grounding circuit in time when there is an electric leakage, so as to prevent the current from passing through the human body and ensure personal safety.
3. Maintain equipment
In the process of line or equipment maintenance and overhaul, generally in order to ensure the safety of the staff, the connection between the equipment and the power system must be cut off first. At this time, the grounding switch can easily cut off the grounding circuit to ensure the safety of the staff and the normal maintenance of the equipment.
In different fields, the definition of low voltage switch will be different. However, the main functions of the low-voltage switch are: switching, protection, control detection and adjustment.
Post time: Jun-26-2023