Schneider Electric urges machine builders seek guidance when using EN 954-1

With the European Commission allowing EN 954-1 to continue for a further two years, many machine builders will carry on using this standard to support compliance to the Machinery Directive, despite the introduction of EN ISO 13849-1 and EN 62061. Peter Still, industry standards manager at Schneider Electric, explains: "Despite EN 954-1 having been published many years ago, there is still widespread misuse which stems largely from the so-called 'risk graph' in an informative annex to the standard. What is often not understood is this graph illustrates just one small aspect of the standard and is not a full summary of the requirements. Consequently, those focussing on this element alone are not complying correctly and therefore not achieving the safest machines possible." "By not reading the standard in its entirety, machine builders are not addressing the risks correctly and often assigning too high a category - spending more money than is necessary. For instance, a single category might have been wrongly assigned to a machine, when in fact if the standard had been read fully, the category would be selected for each safety-related part of the control system according to the degree of risk reduction provided by that part, thus optimising both the safety aspects and overall cost of the control system." To help those operating in the industry to understand EN 954-1 and how to comply, Schneider Electric is urging them to read a European Committee for Standardisation (CEN) report, CR 954-100, which although not widely known, has been available for some years and gives useful guidance on how to correctly use the standard. Mr Still continues: "While the 'risk graph' can be a useful tool, it is an illustration of just one small part of the process of using the standard correctly. With the introduction of EN ISO 13849-1 and EN 62061, now is a good time to reassess how a machine's safety is achieved. Those sticking to using EN 954-1 will find that if they do so correctly, the transition to the new standards further down the line, particularly EN ISO 13849-1, will be much easier as it uses some similar basic principles." "Better still, there is no reason why machine builders shouldn't start using the new standards now, as they focus on the correct operation of safety functions, making it possible to achieve greater levels of safety throughout the machine's life. In any case, it will be necessary to stop using EN 954-1 before the withdrawal of its presumption of conformity in 2011." The CR 954-100 report is available from the British Standards Institution as PD CR 954-100:1999 or visit the Schneider Electric website at the link below.