This new Directive 2006/42/EC makes key changes to the Declaration of Conformity. The person who is authorized to compile the Technical File must be established in the European Community. Where appropriate, there must be a statement confirming Declaration of Conformity with other applicable directives. And there is no longer a separate declaration for safety components, and the declaration must be typewritten or handwritten in capital letters.
There are also significant additions and changes to the essential health and safety requirements (EHSRs) that will affect machine design, including requirements for guarding and control systems. Some of the safety devices that fall under the scope of the Directive include, as already mentioned, control devices for calling lifting appliances and anti-fall devices for hoists, plus monitoring devices for loading and movement control in lifting machinery – as well as solenoid valves controlling dangerous movements of machinery.
Control systems, says the Directive, must be designed and constructed in a way that will prevent a hazardous situation arising. Manual controls must be clearly visible and identifiable, and the use of pictograms is recommended. And an operator must, from each control position, be able to ensure that no one is in the danger zone – even if that means that the machinery can be controlled only from positions in one or more predetermined zones or locations.
Starting is covered as well; the Directive states that it must be possible to start machinery only by the voluntary action of a manual control provided for that purpose. The restarting of a machine or a change in operating conditions may however be effected by the voluntary action of a device other than the manual control provided for that purpose, unless this would lead to a dangerous situation. There are obviously many more issues contained within the new Machinery Directive, and it is vital that business organizations move in good time to make sure that they comply. But it is worth underlining here that in terms of control integrity, there are other European Standards in force that are also relevant.
EN 954-1 Safety of Machinery – Safety Related Parts of Control Systems, the standard that previously applied to all safety-related parts of control systems will be replaced by two standards that co-exist. The original standard will remain valid until November 2011 to provide a period of transition to the new version. People that design and install electronic safety systems can choose between the requirements of either EN ISO 13849-1 or EN/IEC 62061, and still fully comply with the European Machinery Directive.
In general terms, EN ISO 13849-1 takes a four-stage approach to the design of safety-related control systems:
- Perform a risk assessment (EN ISO 14121);
- For the identified risks, allocate the safety measure (Performance Level or PL);
- Devise a system architecture that is suitable for the PL;
- Validate the design to check that it meets the requirements of the initial risk assessment.