Understanding the Different Types of Button Switches and Their Functions

1. The button switch can complete basic control such as start, stop, forward and reverse, speed change and interlock. Typically each push button switch has two pairs of contacts. Each pair of contacts consists of a normally open contact and a normally closed contact. But when the button is pressed, the two pairs of contacts act at the same time, the two pairs of normally closed contacts are disconnected first, and then the two pairs of normally open contacts are closed.

In order to indicate the function of each button and avoid misuse, the button caps are usually made into different colors to show the difference. The colors are red, green, black, yellow, blue, white, etc. For example, red means stop button, green means start button, etc. The main parameters of the push button switch include the type and size of the mounting hole, the number of contacts and the current capacity of the contacts, which are detailed in the product manual.

2. 2. Classification: Classified by operation mode and protection mode

3. Buttons can be classified according to operation mode and protection mode. Common button categories and characteristics:

4. (1) Open type button switch: suitable for embedded and fixed on the panel of switch board, control cabinet or console. Code named K.

5. (2) Protective type button switch: with a protective shell, which can prevent the internal button parts from being mechanically damaged or people touching the live parts, the code is H.

6. (3) Waterproof button switch: with a sealed shell to prevent rainwater

7. (4) Anti-corrosion type: it can prevent the intrusion of chemical corrosive gases. Code named F.

8. (5) Explosion-proof type: It can be used in places containing explosive gas and dust without causing explosion transmission, such as coal mines and other places. Code named B.

Nine. 

(6) Knob type switch: The contact is operated by rotating the handle, with two positions of on-off, generally panel-mounted. Code named  X.

10. (7) Key button switch: use a key to insert and rotate for operation, which can prevent mis operation or be operated by a special person. Code named Y.

11. (8) Emergency button switch: There is a big red mushroom button protruding outside, which is used to cut off the power supply in case of emergency. Code named J or M.

12. (9) Self-holding button: The button is equipped with a self-holding electromagnetic mechanism, which is mainly used in power plants, substations or test equipment. Operators

13. (10) Illuminated button: There is a signal light inside the button, which is not only used to issue operation commands, but also serves as a signal indicator, and is mostly used on the panels of control cabinets and consoles. Code named D.