Push button switch is a kind of electrical appliance that acts when pressed and resets when released, which is used to turn on and off small current circuits. It is generally used in the control circuit with AC / DC voltage below 440V and current less than 5A. Generally, it does not directly operate the main circuit, but can also be used in interconnected circuits.

In actual use, in order to prevent misoperation,push button switches are usually marked or painted with different colors, including red, yellow, blue, white, black, green, etc. Generally, red indicates operation under “stop” or “dangerous” conditions; Green means “start” or “on”. The emergency stop button must be a red mushroom head button. The button must have a metal protective retaining ring, and the retaining ring shall be higher than the button cap to prevent accidental touch of the button and misoperation. The material of the button board and button box for installing the button must be metal and connected to the main grounding bus of the machine.