Glossary · Safety standards
ISO 13849-2
Also known as: ISO 13849-2:2012, EN ISO 13849-2
German: ISO 13849-2
ISO 13849-2 is the international standard for the validation of safety-related parts of control systems designed under ISO 13849-1. It specifies the procedures and conditions for validation by analysis and testing, and contains lists of safety principles and fault lists for different technologies.
- Standards
- Technical documentation
In one sentence
ISO 13849-2 covers validation of safety-related control parts designed to ISO 13849-1, by analysis and testing with technology-specific fault lists.
Example
To validate the Category 3 guard interlocking of a CNC machine, the team prepares a validation plan, analyzes the circuit against the electrical fault list and tests the reaction to a simulated welded contact.
How it applies
- Validation process: A validation plan defines what is validated, by whom and how. Analysis comes first; testing complements it where analysis alone is not conclusive.
- Annexes: Technology-specific annexes list basic and well-tried safety principles, well-tried components and fault lists for mechanical, pneumatic, hydraulic and electrical systems. They support fault considerations and justified fault exclusions.
- Technical documentation: Validation results, including the faults considered and excluded with their justification, belong in the technical file. They are the evidence that the specified safety functions and categories are achieved.
- Changes: A change to the safety-related control system requires revalidation of the affected functions.
Validation vs. verification
In ISO 13849, verification shows that the design achieves the specified PL, largely through calculation and analysis against part 1. Validation shows that the safety functions and their specification are correct and suitable for the machine, following part 2. Both are needed, and they answer different questions.