What is intelligentized content and working principle of contactor?(part 1)

The current contactors, circuit breakers and protectors, such as thermal relay, are all mechanical non intelligent in our country. Generally, it is AC absorption, AC absorption and random separation, and the voltage of the line packet has 220V and 380V. The experiment tells us whether 220V or 380V's line package can be reliably pumped together with the DC voltage of not less than 160V, and it will not generate one or two bounce.

At this time, as long as the suction voltage is not less than the DC 15V, the absorption state can be maintained steadily. Once the breaking process occurs, it is bound to be accompanied by an arc. The only principle to determine when the breaking process occurs is that the total energy of the arc is minimized under the premise of time allowed.

For a single-phase electromagnetic circuit, the best time to break contacts should be zero crossing of main circuit current. For three-phase electromagnetic circuit, if the breaking process occurs at zero crossing time of a phase, the total energy of three-phase arc should be minimum. The zero crossing of the three contacts is controlled by rotation, which can enable them to have the same service life.

https://www.dhirubhai.net/pulse/how-make-daily-maintenance-circuit-breakerspart-1-binbin-shen/

https://www.dhirubhai.net/pulse/how-make-daily-maintenance-circuit-breakerspart-2-binbin-shen/

https://www.dhirubhai.net/pulse/how-make-daily-maintenance-circuit-breakerspart-3-binbin-shen/