The CJ20 series AC contactor is a widely used power device. The following is a detailed product information introduction:

I. Basic Overview

The CJ20 series AC contactor was released and implemented by the Ministry of Machinery Industry of the People's Republic of China in 1997 (standard number: JB 8591.1-1997), and a revised version of the standard was released by the National Development and Reform Commission in 2007 (JB/T 8591.1-2007). This series of contactors is mainly used for remote control of the connection and disconnection of three-phase AC motors, suitable for AC 50Hz (expandable to 60Hz), rated voltage up to 660V (derivative specifications up to 1140V), and current up to 630A power systems.

II. Technical Characteristics

Structural Features ：

* Adopts a direct-acting double-break three-dimensional layout structure, simple and compact structure.

* CJ20-25 and below specifications adopt a two-layer, two-section design without arc chutes; 40A and above specifications use a two-layer upright structure, with the main contacts and arc chutes installed independently.

* The auxiliary contact module adopts an independent component design, with high scalability.

Contact System ：

* The main contacts use silver-based alloy materials, with good conductivity and wear resistance.

* The arc extinguishing system adopts a double-break grid arc extinguishing chamber structure, effectively extinguishing the arc.

Electromagnetic System ：

* The electromagnetic system adopts an E-type iron core (CJ20-40 and below) or a U-type iron core (CJ20-63 and above), with a buffer device to reduce vibration and noise.

* The coil pick-up voltage range is 80%-110% of the rated voltage, with strong adaptability.

Performance Indicators ：

* Mechanical life reaches 6 to 10 million times, high electrical life.

* Operating frequency is 600-1200 times/hour depending on capacity.

* The contactor body protection level reaches IP00, requiring an installation environment altitude not exceeding 2000 meters, and a pollution level of 3.

III. Application Range

The CJ20 series AC contactor is mainly used in machine tool equipment and three-phase motor control in power distribution systems. It can also be combined with a JR20 thermal relay to form a magnetic starter, achieving overload and phase-failure protection for the motor.

IV. Installation and Maintenance

Installation Conditions ：

* The installation location altitude does not exceed 2000 meters.

* The ambient air temperature upper limit is +40℃, the lower limit is -5℃, and the average temperature value within 24 hours does not exceed +35℃.

* The relative humidity of the atmosphere does not exceed 50% at +40℃, and can be higher at lower temperatures.

* Installed in an environment without significant shaking, impact vibration, explosion hazards, and corrosive gases.

Maintenance Requirements ：

* Regularly inspect and maintain the contactor, cleaning surface dirt and dust and dirt on the iron core pole surface.

* If severe contact erosion is found and it cannot work normally, the contacts should be replaced.

* When the contactor is overhauled, the power supply should be cut off to ensure safety.

V. Common Models and Specifications

Common models of the CJ20 series AC contactor include CJ20-10, CJ20-16, CJ20-25, CJ20-40, CJ20-63, CJ20-100, CJ20-160, CJ20-250, CJ20-400, CJ20-630, etc., with rated operating currents covering the range of 6.3A to 630A.

In summary, the CJ20 series AC contactor features a compact structure, stable performance, and strong adaptability, and is widely used in power distribution systems and machine tool equipment. During installation and maintenance, operations should strictly follow the product manual and relevant standards to ensure normal operation and extend service life.