Nödstoppknappen

Nödstoppknappen, or emergency stop button, is a safety device used to immediately halt machinery in case of dangerous conditions. It is designed to stop all motion and power to the equipment as quickly as possible to prevent injury or damage. E-stops are intended for urgent intervention, not for regular process control.

Typically a red, mushroom-shaped pushbutton with a yellow bezel, the device is mounted within easy reach of operators. The colour scheme and symbol are standardized to ensure rapid recognition. In many countries, the stop circuit is wired into a safety circuit and is separate from normal stop functions.

When pressed, the E-stop disengages the machine's control system, often latching in the depressed state until a deliberate reset is performed. Restart usually requires a reset action or a turn/key, and the device must allow safe re-energization only after the situation is assessed and the risk is mitigated. E-stops should be clearly accessible and protected from accidental operation yet free from environmental hazards that could affect function.

Standards such as EN ISO 13850 (Emergency stop devices - Functional characteristics) specify performance requirements and testing. Electrical safety can fall under EN 60947-5-5 and ISO 13849-1 for safety-related control systems. Proper installation includes redundant circuits, regular testing, and labeling. In Europe, emergency stop devices are governed by EN ISO 13850 and the Machinery Directive 2006/42/EC.

Regular inspection, cleaning, and functional testing are required. Damaged buttons must be replaced; the area around the device should be free of obstacles; operators should be trained on its proper use and the procedure to safely restart equipment after an emergency stop.