A push-button switch-also known as a control button (or simply a "button")-is a manually operated, low-voltage electrical device that typically features automatic reset functionality. These buttons are commonly used in circuits to issue start or stop commands by controlling the energization and de-energization of coils in devices such as electromagnetic starters, contactors, and relays.
A push-button switch is a device designed to make or break low-current circuits; it activates when pressed and resets when released. It is generally used in control circuits with voltages up to 440V (AC/DC) and currents below 5A. While typically not used to directly operate main power circuits, it can be employed in interlocking circuits.
In practical applications, to prevent accidental operation, buttons are often distinguished by specific markings or colors-such as red, yellow, blue, white, black, or green. Generally, red indicates "stop" or an emergency/danger condition, while green indicates "start" or "activate." Emergency stop buttons must feature a red mushroom-shaped head. Buttons must be equipped with a protective metal guard ring that extends above the button cap to prevent accidental actuation. The mounting panels and enclosures for these buttons must be made of metal and connected to the machine's main grounding busbar.
