Breaker

Thông tin chi tiết

1. What is a switchgear?
- Circuit breaker is an electrical device used to perform the role of switching and controlling as well as protecting electrical circuits and electrical equipment from electrical incidents. This is a general term for switching devices.
- Switchgear is a combination of electrical switching devices with the functions of switching, controlling, measuring, adjusting, isolating and protecting electrical circuits and equipment.
- Some products included in switchgear include switches, circuit breakers, transfer fuse sets, HRC fuses, load reduction isolators and earth leakage circuit breakers (ELC Bs). These devices are properly assembled to form switchgear.

2. Basic features of switching equipment

- Complete reliability: Continued connection as well as increased capacity of generating stations calls for the installation of reliable switchgear. Equipping switchgear is paramount to improving reliability. Thus, when there is a fault in the electrical system, the switchgear must work to separate the faulty part from the rest of the circuit.
- Provision for manual control: Reliable switchgear should have manual control whereby critical operation can be performed through manual control whenever there is a failure in the control electricity.
- Fast Operation: When a fault occurs on any part of the power system, the switching devices must operate quickly to prevent short-circuit current damage to transformers, generators as well as Other devices. When a bug is not resolved quickly, it can spread to other secure areas, thereby jeopardizing the system's complete shutdown.
- Completely distinguishable: Whenever there is a fault on any part of the electrical system, the switchgear must be able to distinguish between the safe part and the faulty part. Therefore, it can separate the faulty part from the system without affecting the safety part to ensure the continuity of power supply.
- Flexibility and adjustment: It can be adjusted to suit a variety of loads and currents, providing flexibility to the electrical system.
- Signaling and warning: Some switchgear is capable of signaling when a fault occurs or providing warning information to the operator about the condition of the circuit.

3. Components of switchgear

Basically, the switchgear will include some of the following common protection and switching devices:
- Air Circuit Breaker (ACB stands for the English phrase "Air Circuit Breaker"): is a device that is widely used in power distribution systems for construction and civil works,... with The purpose is to ensure continuous supply and high cutting current reliability.

Máy cắt không khí ACB

- Earth leakage circuit breaker (ELCB stands for the English phrase "Earth leakage circuit breaker"): often named in different ways as "Earth fault protection relay", "anti-shock circuit breaker", "bridge". anti-leakage knife". ELCB is a type of device that works on the principle of detecting the difference in incoming and outgoing currents so that it can turn off the consumption source if there is a difference between them. ELCBs are used to protect the safety of the power grid, more importantly human safety from the risks of "electric shock".

- MCCB circuit breaker (also known as block circuit breaker): is manufactured to safely control and protect the electrical circuit. The device helps to safely close and close electrical circuits when current problems occur such as: overload, short circuit or circuit voltage drop.

- MCB circuit breaker: is a type of circuit breaker designed with a number of poles corresponding to the number of circuits, ranging from 1 to 4 poles, possibly more depending on the design of each brand.

- RCBO circuit breaker (Aptomat RCBO): is also a product of the anti-shock CB line, meaning that in addition to the short-circuit overload protection function like other conventional CBs, this type of CB has an additional protection feature when detecting detects leakage current in the electrical circuit, helping to better protect the electrical circuit, operating electrical equipment and especially the safety of users.

- Magnetic starter (also known as Contactor): is a device used to control opening/closing of equipment indispensable in systems. Its use is to ensure the safety of devices. There are many types of contactors such as: electronic contactor, pneumatic contactor, hydraulic contactor, 1-phase contactor, 2-phase contactor, 3-phase contactor.....

- Thermal relay: is a type of electrical device to protect motors and electrical circuits from overload, often used with contactors. Thermal relays have the function of automatically closing contacts thanks to the thermal expansion and contraction of metal bars.

- Protective Relays (Protective Relays, Protection Relays): is a type of electromagnetic device, it is based on the operation of electromagnetic coils acting on transmission parts to detect abnormal operating conditions such as overheating. current, overvoltage, reverse power flow, frequency too high or low.

Depending on different manufacturing characteristics, some devices will be able to operate well under normal and abnormal current conditions. On the contrary, many devices can only undertake the task of converting the power source without being able to detect electrical problems that occur.
Under normal current conditions, the switching device will perform the task of turning on/off generators, distributors, power transmission lines... However, when a large current flows through and the device senses This threat can endanger electrical equipment and quickly disconnect unsafe connections from the system.

4. Classification of switching equipment

Switchgear is divided according to voltage level. There are three main types of switchgear as follows:
- High voltage (HV) switchgear
- Medium Voltage Switchgear (MV)
- Low voltage (LV) switchgear
Overall, electrical energy is an important part of life. Therefore, power distribution must be done reliably and safely. Security levels can be maintained at various distribution units as well as substations through the installation of safety mechanisms and devices. While many mechanisms can help secure electrical connections in industrial and residential areas, the use of switchgear is recommended because of its features and functionality.
5. Application of switching devices
- Used to protect generators: In generators there will usually be hundreds of amps and high gen requirements. Therefore, when using switchgear, it is also capable of handling the current capacities. And at the same time it will also provide protection when needed.
- Power supply protection: If you are using a charging circuit to distribute power with a stored power of up to hundreds of amps. Then in some cases you can use additional circuits to install electrical devices. In both of these situations, switchgear is very useful.
- Welding machines: Because small circuit breakers cannot handle high currents while some welding applications draw very high currents. Therefore, the switchgear is the most perfect choice for replacement.
- Capacitor protection: Switchgear is often used to protect capacitors. Because it can regulate power factors in a commercial and industrial power system. When it senses that the current is very high, the switching device will operate to help reduce the current effectively.
- Motor protection: Switchgear will play a very good role in protecting electric motors. This device will be regulated at the input current and protected against overload current when needed without stopping operation.