1 AC contactor. It is mainly composed of electromagnetic mechanism, contact system and arc extinguishing device. Commonly used are CJ10, CJ12, CJ12B series.
2. DC contactor is generally used to control DC electrical equipment. The coil is connected with DC current. The operating principle and structure of DC contactor are basically the same as that of AC contactor.
Type and meaning of contactor. It's all AC series.
1. Class AC-1 contactors are used to control inductance-free or micro-inductance circuits.
2. AC-2 contactor is used to control the start and break of winding asynchronous motor.
3. AC-3 and AC-4 contactors can be used to frequently control the starting and breaking of asynchronous motors.
AC contactors are generally divided into main contacts and auxiliary contacts, the main contacts are used to connect and disconnect the main power supply circuit of low-voltage electrical equipment, relatively large contact capacity. The auxiliary contacts are used in the control circuit. They are usually open and closed. Because the current in the control circuit is relatively small, the capacity of the auxiliary contacts is much smaller than that of the main contacts.
The relay is only used in control and protection circuits, but it can control high current and high voltage equipment with small current and low voltage in the circuit. It can also expand the capacity of contacts when the capacity and quantity of contacts are insufficient. According to the different functions of relays, they can play different roles in the control circuit, such as time relay, current relay, voltage relay, intermediate relay, signal relay and so on. The coils of relays can be divided into voltage, current, direct current and alternating current. They are used in different circuits according to the requirements of the circuits. Because the current of these circuits is generally small, the contact capacity of relays is relatively small, so they can not be directly used in the main power circuit.
Working Principle: The coil of contactor is connected to the control loop of low voltage equipment. When the voltage of both ends of the coil reaches 70% of the rated value, the core magnetically saturates the armature and drives its main contact point to connect the main power supply to the electrical equipment. When the coil of contactor loses power, the armature is released and the main contact point disconnects and cuts off the main power supply of the equipment. Source.
The coil of relay is connected to the corresponding circuit according to the difference of DC, AC, current and voltage. When the condition of coil suction is satisfied, the armature is sucked and the corresponding action of its normally open and closed contacts is driven. It plays different roles in the circuit. Some relays can be charged for a long time, while others can not, so some relays in the circuit. Electrical equipment will not be shut down even if it loses power, and some relays will not cause the equipment to start up and run even if it gets power.
