turvallisuuspiktogrammien

Turvallisuuspiiri, known in English as a safety circuit, refers to an electrical or electronic arrangement designed to prevent harm by detecting hazardous conditions and initiating protective actions such as machine shutdown, power isolation, or safe-stop routines. It is a core component of functional safety in industrial automation.

Typical turvallisuuspiiri components include safety sensors (emergency stop devices, safety interlocks, light curtains), a safety logic element (safety relay or safety PLC), actuators, and a control power supply. The circuit is designed to remain or become fail-safe so that a fault leads to a safe condition rather than an unsafe one. Diagnostic features monitor health and signal faults.

Design and assessment follow standards such as ISO 13849-1 and IEC 62061 (SIL-based approaches), and frameworks like ISO 61508. Designers assign performance levels or safety integrity levels to demonstrate risk reduction. Redundancy, monitored fault paths, safe de-energization, and regular testing are typical strategies.

Operation involves continuous monitoring, fault detection, and a defined response to faults or hazards. After installation, turvallisuuspiiri installations require periodic testing, maintenance, and documentation to sustain compliance and safety performance.

While important, a turvallisuuspiiri is not a substitute for overall machine guarding and safe operating procedures. It complements physical barriers, training, and risk assessment to reduce injury risk in industrial environments.