vacuum contactors
Vacuum arc extinguishing chamber is used to connect and cut off the normal operating current, which is usually used to connect and disconnect the 6kV, 380V (1140V, 660V) AC motor.
Form
The vacuum contactor is composed of the vacuum arc extinguishing chamber and the operating mechanism. The vacuum arc extinguishing chamber has two functions, which are reliable and arc extinguishing through normal working current and frequent cutting off working current. But can not cut off the load current and short-circuit current. The operating mechanism is composed of a belt core holding coil and armature structure. The coil is energized, the armature contactor coil; attract, loss of power, disconnect contactor. The suction coil generally has two forms of DC and AC.
The vacuum chamber is made of glass or ceramic insulating material, and the vacuum degree is usually above 0.01Pa. Because of the air inside the shell, the contact distance can be very small, and the electric arc can be easily extinguished. The contact material is usually made of copper, antimony, osmium alloy etc.. Arc in arc chamber shield is, when the current is broken, condensation contact gap in the diffusion of metal vapor, contribute to the extinction, also can prevent metal vapor splashed on the insulating casing to reduce the insulation strength. The movable contact and the lower end of the casing are connected with the corrugated pipe, and the movable contact can be moved up and down and the movement can not leak.
The arc extinguishing ability of the vacuum contactor is good, the pressure resistance is good, the operating frequency is high, the life is long, and no electric arc spraying.
Vacuum contactor circuit diagram
Product is small, light weight, maintenance cycle is longer. The vacuum arc extinguishing chamber is very high. If the process is bad, the vacuum of the arc chamber is easy to fall. Contact material is not good, in the break current will appear “cut off” phenomenon, that is, the point of breaking current, due to the vacuum arc extinguishing ability is very strong, the arc current is not natural zero crossing, but from the current value of a sudden drop to zero, resulting in high voltage. Closure voltage will endanger the safe operation of electrical equipment.