Product structure
1、 The AC contactor adopts an electromagnetic mechanism to drive the main circuit, and the separation and combination of the main contact points are controlled by the electromagnet and the main contact system.
2、 The main contact point of an AC contactor is used for connecting and disconnecting the AC power supply, and can also be used as a conversion circuit.
3、 The contact system of AC contactor is generally composed of two main contacts and two auxiliary contacts which are fixed on the bracket.
4、 The AC contactor coil is installed on the iron core, and there are insulating sheets and windings around the coil. The windings are generally 300 ~ 350 m in length.
5、 The contact system of AC contactor is composed of arc extinguishing devices, which can be generally divided into two types: isolation type and non-isolation type. The isolation type includes air insulation arc extinguishing device and metal dielectric arc extinguishing chamber, while the non-isolation type includes carbon arc gas preserving gas or vacuum arc extinguishing device.
Principle of operation
When the AC contactor energizes the electromagnetic coil, the electromagnet attracts the coil and the coil current passes through the load circuit to generate the electromagnetic torque. At the same time, because the iron core has a magnetic field, the electromagnetic force generated causes the movable iron core to move and suck the contactor coil. When the coil current disappears, the magnetic field disappears, the spring returns the moving core to its original position, and the contactor immediately disconnects the circuit.
When the coil of the AC contactor is electrified, its potential is related to the load resistance. High resistance makes the current pass through less and consumes less electric energy. When the AC contactor when the current generated by the coil larger, so in the main contact to form a certain amount of heat.
The heat generated in the circuit is as follows:
3、 Heat generated by the action of the main contact
4、 Heat generated by the expansion of the gas in the cover;
5、 heat generated by mechanical abrasion;
Technical parameters
1、 Rated voltage: AC380V or AC380V, 60Hz.
3、 Working frequency: 20Hz ~ 40Hz.
4、 The highest working temperature of the coil: – 25 ℃ ~ + 55 ℃.
5、 Arc extinguishing capacity: arc pressure in the arc extinguishing chamber shall be able to ensure that the time of one ignition is more than 3ms at 100W, and generally adopt 30W arc extinguishing device.
6、 The voltage drop of the contactor shall not exceed 2% or 5% of the rated voltage.
8、 Startup time: less than or equal to 0.1S (for rated current of more than 30A, startup time shall be less than 0.045S); for current of less than 20A, startup time shall be less than 0.25S.
10、 Minimum working temperature: at – 25 ℃, allow short working hours of 0 ~ 40 min, maximum working hours of 20 min.
Cautions
1. The voltage level used for the AC contactor must meet the rated voltage specified by the product.
2. Before the use of the AC contactor, check whether its appearance is damaged, whether the parts are complete, and whether the terminals are loose or come off.
3. In areas where the power supply voltage fluctuates greatly, the AC contactor shall be equipped with corresponding compensation devices.
4. When the AC contactor is wired, the model of the terminal shall be carefully checked, and corresponding measures shall be taken if the phase sequence or parameters are found to be inconsistent.
5. When testing new products, the AC contactor shall carefully check whether the rated working voltage, rated working current and protection setting value meet the requirements.
6. Spark, arc and other strong electromagnetic interference may occur when the main contact of the AC contactor is broken. They should therefore be checked regularly in case of dangerous situations.
Post time: Feb-22-2023