Why are there three connection points for the micro switch?

This kind of micro switch is a "relay contact type" micro switch. The relay has an open point NO and a closed point NC. Each type of contact corresponds to two terminals, that is, four wires. The switch here has 3 wires because the two contact power supplies are shared, and the other two wires, one is the normally open point NO, and the other is the normally closed point NC.

Rated value: generally refers to the value that is used as a guarantee of the switching characteristics and performance, such as rated current, rated voltage, etc., and the premise is specific conditions (load type, current, voltage, frequency, etc.).

Resin fixing (plastic-sealed terminal): After wiring the terminal with a wire, fill the part with resin to fix the part and eliminate the exposed live part to improve the drip resistance.

Insulation resistance: refers to the resistance between non-connected terminals, between terminals and uncharged metal parts, and between terminals and ground.

Withstand voltage: The critical value that will not cause insulation damage after applying a high voltage for 1 minute at the specified measurement location.

Contact resistance: It means the resistance of the contact part of the contact, but generally means the resistance value including the spring and the conductor resistance of the terminal part.

Vibration resistance: Misoperation vibration When the micro switch is in use, the contact closed due to vibration does not separate within the specified time.

Impact resistance: Durable impact means that the micro switch will not be damaged by the mechanical impact during transportation or installation, and will meet the impact within the range of operating characteristics. Misoperation impact? Refers to the impact range where the contact closed due to impact does not separate within a specified time when the micro switch is used.