Nødavstengning

Nødavstengning, or emergency shutdown, is a safety mechanism designed to immediately halt equipment, processes, or power when a hazardous condition is detected or anticipated. It is used across industries such as manufacturing, energy, and transport to reduce the risk of injury, damage, or environmental harm and is typically integrated into broader risk management and process safety systems.

Nødavstengning can be manual, automatic, or a hybrid of both. Manual devices usually consist of red pushbuttons or mushroom-head switches that latch in the off position when pressed. Automatic emergency shutdowns are triggered by sensors or control logic that detect abnormal or dangerous conditions. In modern systems, the emergency stop function is fail-safe and often requires a deliberate reset before normal operation can resume.

Key design features include accessibility and clear marking, protection against accidental activation, and integration with the control system to interrupt energy or motion according to a defined safety function. The status and integrity of emergency stops are typically monitored, tested, and maintained as part of routine safety management.

Standards and regulation: international standards such as ISO 13850 (Safety of machinery — Emergency stop) and IEC 60204-1 (Electrical equipment of machines) provide guidance on the design and performance of emergency stop systems. Other standards, such as EN 418, relate to emergency stop devices. National regulations may specify additional requirements for inspection, testing, labeling, and documentation.

Operation and maintenance: routine functional testing, inspection, and maintenance of emergency stop devices are essential. After activation, a reset by authorized personnel is usually required, and fault investigations should follow to prevent recurrence. While crucial, nødavstengning complements, rather than replaces, comprehensive safety design and risk control.