Generally with the contactor model after 2 digits as the rated current reference value, such as:
CJX2-3210: Rated current 32A, usually open contact pay.
CJ10-40: Rated current 40A. There are many kinds of AC contactors, and their classification methods are not the same. According to the general classification method, there are roughly the following.
(1) According to the main contact pole points can be divided into unipolar, bipolar, three-pole, quad-pole and five-pole contactors. Unipolar contactors are mainly used for single-phase loads, such as lighting loads, welders, etc., which can also be used in motor energy braking, bipolar contactors are used in the rotor circuit of winding asynchronous motors, and short starting windings are used when starting, and tripolar contactors are used for three-phase loads, such as in motor control and other applications, and are most widely used. The quad-pole contactor is mainly used for three-phase, four-wire lighting lines, and can also be used to control the load of two-circuit motor, and the five-pole AC contactor is used to form a self-coupled compensator starter or a controlled double-cage motor to transform the winding method.
(2) According to the arcing medium can be divided into air-type contactors, vacuum contactors and so on. Air-insulated contactors are used for general loads, while vacuum insulated contactors are commonly used in coal mines, petroleum, chemical enterprises and special occasions such as voltage at 660V and 1140V.
(3) According to the contact points can be divided into contact contact contacts and contactless contacts. Common contactors are mostly contact contact contacts, and contactless contactors are the product of electronic technology applications, generally using the thyristor as the circuit break element. Because the trigger voltage required for SCR on is small and no sparks are generated when the circuit is broken, it can be used in high operating frequencies and in flammable, explosive, noise-free applications.
2. Basic parameters of AC contactors
(1) Rated voltage refers to the main contact rated operating voltage, should be equal to the rated voltage of the load. A contactor often specifies several voltage ratings and lists the corresponding rated current or control power. Typically, the maximum operating voltage is the rated voltage. Commonly used voltage ratings of 220V, 380V, 660V and so on.
(2) The current value of the rated current contactor contact under rated operating conditions. In the 380V three-phase motor control circuit, the rated operating current is approximately equal to twice the control power. Commonly rated current ratings are 5A, 10A, 20A, 40A, 60A, 100A, 150A, 250A, 400A, 600A.
(3) The pass-off capability can be divided into maximum on-on current and maximum split-off flow. The maximum on current is the maximum current value that does not cause contact welding when the contact is closed, and the maximum disconnection is the maximum current that reliably extinguishs the arc when the contact is open. The general pass-off capacity is 5 to 10 times the rated current. Of course, this number is related to the voltage level of the power-off circuit, the higher the voltage, the smaller the power to break.
(4) The action values can be divided into suction voltage siphoning voltage and release voltage. The suction voltage refers to the contactor before the suction, slowly increase the voltage at both ends of the suction coil, the contactor can absorb the minimum voltage. The release voltage refers to the contactor suction, slowly reduce the suction coil voltage, contactor release of the maximum voltage. Generally, the suction voltage is not less than 85% of the coil rated voltage, and the release voltage is not higher than 70% of the coil rated voltage
(5) Attract coil rated voltage The voltage value added to the coil is when the contactor is working properly. Generally, the voltage value and the coil's number of turns, wire diameter and other data are marked on the wire package, not marked on the contactor shell nameplate, should be used with attention.
(6) Operating frequency Contactor in the suction moment, attract coil needs to consume 5 to 7 times the rated current current, if the operating frequency is too high, it will make the coil serious heat, directly affect the normal use of the contactor. For this reason, the permissible operating frequency of the contactor is specified, which is generally the maximum number of times allowed per hour.
(7) Life includes electrical life and mechanical life. At present, the mechanical life of contactors has reached more than 10 million times, the electrical life is about 5% to 20% of the mechanical life
Contactor model description
For AC contactors, the design serial number 10, heavy task type, rated current 40A main contact is 3 poles. CJl2T-250/3 is a modified AC contactor with a design serial number 12, a rated current of 250A, and three main contacts. China's production of AC contactors commonly used CJl0, CJl2, CJX1, CJ20 and other series and its derived series, CJ0 series and its modified products have been gradually replaced by CJ20, CJX series of products. The above series of products generally have three pairs of normally open main contacts, normally open, normally closed auxiliary contacts each two pairs.
DC contactors are commonly used cz0 series, divided into two types of single-pole and bipolar, normally open, normally closed auxiliary contacts each no more than two pairs.