Those things about relays, contactors, electrical contacts, contacts

Those things about relays, contactors, electrical contacts, contacts. Regarding electromagnetic relays and contactors, I believe all electricians are familiar with them. Knowledge about these two kinds of electrical equipment has long been shared by many peers. Today, the author only supplements the contact knowledge of electromagnetic relays and contactors.

The contact burning failure of electromagnetic relay and contactor is a common problem in our work. The reasons for this situation are nothing more than two possibilities: First, the load current flowing through the contacts is relatively large, very close to the rated value. Although it does not exceed the rated value of the contact, long-term use is easy to cause the contact to burn out; in addition, for the above two types of electrical equipment, especially contactors, most of their loads are inductive loads. Although the load current is not large, when the contacts are opened and released, they are easily damaged by the arc ablation released by the inductive load. As far as electromagnetic relay and contactor contacts are concerned,-series and parallel connection are very popular in some practical applications. In some electrical circuits that require interlocking and interlocking control, if a single contact of a relay or contactor is used, it may happen that the relay and contactor act too fast, causing the circuit to fail to complete the action state switching. At this time, we can eliminate this phenomenon by connecting two or more contacts of the relay and contactor in series, and using the method of increasing the contact action distance-correspondingly extending the action conversion time.

Similarly, it can be known that when the contact capacity of the relay and contactor is damaged due to a large load current, it can be overcome by expanding the contacts in parallel. In short, the causes of electromagnetic relay and contactor contact burning are concentrated and easy to solve. In the electrical control circuit, we can flexibly use contact wire and parallel connection to solve some practical problems.