Achieve a higher safety performance level with EN ISO 13849-1
Over the past few years, safety has become one of the dominant factors that impact product design processes. European guidelines for machine safety have played a major role in reducing injuries and are bringing new requirements for product and component developers in their goal of working toward creating a better and safer working environment.
At the end of 2011, EN ISO 13849-1:2006 “Safety of machinery, Safety-related parts of control systems, Part 1: General principles for design” took effect. The EN 954-1 (CAT B, CAT 2, CAT3 & CAT4) was replaced by ISO13849-1, because programmable electronic systems were considered insufficiently; there was no consideration for direct connection between risk minimization, category, or complexity. Also, time response (e.g., testing intervals, lifecycles) and the failure probability of components (e.g., Common Cause Failures) were not considered. Therefore, due to all these aspects, EN 954-1 did not represent the state of technology anymore.
EN ISO 13849-1 addresses the programmable electronic safety devices that are being used increasingly in modern machines. The standard also provides a quantitative approach to risk assessment and safety validation. This ensures that safety is not solely a matter of component reliability, but also relies on common-sense safety principles such as redundancy, diversity, and fail-safe behavior. Under this standard, the risk assessment for a given safety function will yield a performance level (PL). This helps eliminate both over- and under-engineering, a costly or risky result of EN 954-1’s limitations.
Safety designers should start designing products using EN ISO 13849-1. It improves safety and the experience of working with the new requirements, and will have much greater long-term benefits than using EN 954.
– Information provided by Siemens Industry Inc. Edited by Mark T. Hoske, content manager, CFE Media, Control Engineering and Plant Engineering, firstname.lastname@example.org.