General power relay working principle


A power relay is a device that can be converted in one […]

A power relay is a device that can be converted in one or more electrical output circuits when input (or excitation) meets certain specific conditions. It can be used in a neutral point direct grounding system as a directional component for zero sequence current protection. The action of the contact can be divided into two parts: contact closure and contact disconnection, that is, the pull-in and release process of the smart home relays, which are cyclically switched at a certain frequency to form a contact opening and closing phenomenon. There are many special physical and chemical phenomena, such as contact contact resistance, contact jitter, and arcing, during contact closure and opening.
The principle of action when the contacts are closed.

1. When the moving contact and the static contact of the relay are in contact with each other, the contact rebound occurs, that is, the uncontrolled gap opening and closing. The arc generated by the arc and the energizing current at this time greatly affects the opening and closing of the relay Ability;

2. When the contacts are opened and the load is cut, dazzling sparks and arcs are generated, and the arc occurs until the arc voltage drops below the minimum arc voltage value, which causes significant damage to the contacts.
The use of relays requires special emphasis on the fact that if the relay accidentally falls or is subjected to an impact during installation, the electrical parameters may change and the mechanical parameters may vary greatly. There are serious hidden dangers, try to use them in time.