Speaking ofAC contactorsrole, maybe everyone doesn't know what this thing is. AC contactor is a kind of electrical appliance widely used in the power industry, it is mainly used in small current contact with large current. Therefore, we must be extremely careful when using AC contactors, otherwise we may be injured. Although AC contactors may cause us to injure, this does not negate their usefulness. AC contactors still play a great role in us humans. What exactly does it do?Let's take a look.
AC contactor is the most widely used low-voltage control appliance in electric drive and automatic control systems. As an actuator, it is used to turn on and break lines, or frequently control the operation of equipment such as motors. It is composed of dynamic and static main contacts, arc extinguishing covers, dynamic and static iron cores, auxiliary contacts and bracket shells. After the electromagnetic coil is energized, the moving iron core is engaged under the action of electromagnetic force, and the moving contact is in contact with the static contact directly or through the lever transmission, and the circuit is connected. After the solenoid coil is powered off, the moving iron core automatically returns under the action of the return spring, commonly known as release, the contacts are separated, and the circuit is broken.
AC contactor is generally used to start the equipment, using different control wiring methods can control the forward and reverse rotation of the motor, start and stop, and can use the length of the control cable to achieve remote control, change the connection method can also realize the multi-place control system. In addition, in the state of power failure, the motor (machinery) can be kept in a stop state to prevent the motor (machinery) from running in the second time due to the power outage, which will bring unforeseen harm to the operator. Of course, the motor (device) can be considered to be started after an incoming call. There are also AC contactors used with overheat relays or motor integrated protectors, which can protect the motor, burn out due to overload and lack of phase, and achieve the purpose of protecting the motor.
The carrying current of the AC contactor is very large, generally the internal suction coil to control its action or not, and the control coil is operated by various types of relays connected in series with it, after thunder, it will trip because the relay of the AC contactor has the function of overcurrent or grounding protection, when there is lightning on the line, it will control the action of the AC contactor, cut off the load power supply, to protect the equipment, so as not to be damaged by high voltage, high current or grounding safety hazards.
Working principle of AC contactor:
When the coil is energized, the static iron core produces electromagnetic attraction and engages the moving iron core, because the contact system is linked with the moving iron core, the moving iron core drives the three moving contacts to act at the same time, the main contact is closed, and the auxiliary normally closed contact mechanically connected to the main contact is disconnected, and the auxiliary normally open contact is closed, so as to turn on the power supply. When the coil is powered off, the suction disappears, and the linkage part of the moving core is separated by the reaction force of the spring, so that the main contact is disconnected, and the auxiliary normally closed contact mechanically connected to the main contact is closed, and the auxiliary normally open contact is disconnected, so as to cut off the power supply.
One: Generally, the three-phase contactor has a total of 8 points, three inputs, three outputs, and two control points. The output and input are corresponding, and it is easy to see. If you want to add self-locking, you also need to connect the wire from one of the terminals at the output point to the control point.
Two: First of all, you should know the principle of AC contactor. He used an external power supply to add ** to the ring to generate an electromagnetic field. The contact point is disconnected when the power is off. After knowing the principle, you should figure out the contacts of the external power supply, that is, the two contacts of the coil, which are generally at the lower part of the contactor, and on each side. The other inputs and outputs are generally in the upper part, and you can see it at a glance. Also pay attention to the voltage of the external power supply (220V or 380V), which is generally marked as yes. And pay attention to whether the contact point is normally closed or normally open. If there is a self-locking control, it is enough to sort out the line according to the principle.
The role of AC contactors:
The carrying current of the AC contactor is very large, generally the internal suction coil to control its action or not, and the control coil is operated by various types of relays connected in series with it, after thunder, it will trip because the relay of the AC contactor has the function of overcurrent or grounding protection, when there is lightning on the line, it will control the action of the AC contactor, cut off the load power supply, to protect the equipment, so as not to be damaged by high voltage, high current or grounding safety hazards.
1 Classification of uses.
A contactor is an automated control appliance. The contactor is mainly used for frequent switching on or off AC and DC circuits, with large control capacity, long-distance operation, with relays can achieve timing operation, interlocking control, various quantitative control and loss of voltage and undervoltage protection, widely used in automatic control circuits, its main control object is the motor, can also be used to control other power loads, such as electric heaters, lighting, welding machines, capacitor groups, etc. Contactors can be divided into AC contactors and DC contactors according to the type of controlled current. Here we mainly introduce the commonly used AC contactors. AC contactors can be divided into electromagnetic type and vacuum type.
2 Model Description.
1) The above models are standard models, in recent years, the B series AC contactor has been newly developed, and its model is BXX.
2) The model of electromagnetic AC contactor is CJ. The vacuum type AC contactor model is CZ.
3 Structure and working principle of electromagnetic AC contactor.
1) Structure: The contactor is mainly composed of electromagnetic system, contact system, arc extinguishing system and other parts.
Electromagnetic system: The electromagnetic system includes the electromagnetic coil and core, which is an important part of the contactor, relying on it to drive the closing and disclosing of the contact.
Contact System: A contact is the executive part of a contactor and includes the main and auxiliary contacts. The function of the main contact is to turn on and break the main circuit to control the larger current, while the auxiliary contact is in the control loop to meet the requirements of various control methods.
Arc extinguishing system: The arc extinguishing device is used to ensure that the arc generated when the contact is disconnected from the circuit is reliably extinguished, reducing the damage of the arc to the contact. In order to quickly extinguish the arc when disconnected, the contactor is usually equipped with an arc extinguishing device, which is generally a semi-sealed longitudinal seam clay arc extinguishing cover and equipped with a strong magnetic arc blowing circuit.
Other parts: There are insulated shells, springs, short circuit rings, transmission mechanisms, etc.
The above is the introduction of the role of AC contactors, which shows that the role of AC contactors for us is indeed very large. The current carried by the AC contactor is very large, although some accidents caused by the AC contactor will inevitably occur, but we cannot give up the use of the AC contactor. Overall, the advantages of using AC contactors still outweigh the disadvantages. I hope that the above introduction will make you fully aware of the role of AC contactors, especially in the power industry.
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Zhejiang Yishuo Electric Co., Ltd. is a high-tech company specializing in R&D, design, production, sales and service of low-voltage power capacitors, smart capacitors, reactors, reactive power compensation controllers, and reactive power compensation devices.
The company adheres to the tenet of "taking science and technology as the driving force and seeking development by quality", and is committed to building a leading brand of smart grid professional services. The company adheres to the tenet of "taking science and technology as the driving force and seeking development by quality", and is committed to building a leading brand of smart grid professional services.
The company has a high-level R&D management team, integrating R&D, production, sales and service, focusing on intelligent reactive power compensation, harmonic control, energy saving and power quality management and other high-tech industries of power automation.
Over the years, we have adhered to the mission of "making products intelligent and services intimate". In line with a high sense of responsibility to the society and users, Yishuo Electric adheres to the road of specialization, continues to innovate and transcend, and strives to make greater contributions to China's smart grid power automation