1. Normally closed button 2. Normally open button 3. Compound button
2. Classification of button switches: classified by operation mode· protection mode
Common button categories and features:
1. Waterproof: with a sealed case. Can be placed in the water intrusion.
2. Anti-corrosion type: It can prevent the intrusion of chemical corrosive gases.
3. Explosion-proof type: It can be used in places containing explosive gas and dust without causing explosion, such as coal mines and other places.
4. Knob type: Rotate the operating contact by hand, there are two positions on and off, and it is generally panel-mounted.
5. Key type: The key is inserted and rotated for operation, which can prevent misoperation or be operated by special personnel.
6. Open type: suitable for inlaying and fixing on the panel of switch board, control cabinet or console.
7. Protective type: with a protective casing, it can prevent the internal button parts from being mechanically damaged or people touching live parts.
8. Emergency type: There is a big red mushroom head protruding outside, which is used for power off in an emergency.
9. Self-sustaining button: The button is equipped with a self-sustaining electromagnetic mechanism, which is mainly used in power plants· substations or test equipment, where operators communicate signals and issue instructions.
10. Illuminated button: The button is equipped with a signal lamp, which is used for issuing operation instructions and also serves as a signal indication, and is mostly used on the panel of the control cabinet and console.
11. Combination: a combination of multiple buttons.
12. Interlocking: Multiple contacts are interlocked with each other.
