This week: PHOENIX CONTACT Electronics GmbH: requirements for machine safety in wind turbines

Blomberg, 24.04.2012. According to the Machinery Directive, our solutions provide safety technology for the personal and machine protection. For this, we implement the required measures for functional safety.

The EU Machine Directive 2006/42/EC defines the fundamental health and safety requirements that must be complied with during construction and building of machines. As wind turbines are subject to the Machine Directive, manufacturers of these plants have to comply with this directive when installing plants within the European Economic Area. The CE marking on the machine guarantees the compliance with this directive. The Machine Directive is a legislative act and has been implemented as national law (in Germany in the form of the 9th Regulation of the Equipment and Production Safety legislation).

In addition to these legal requirements for wind turbines, there are further standards on which manufacturers can have their plants certified by independent bodies. These are the DIN IEC 61400 and DIN EN 50308 standards, but also the current GL Guidelines (as of 2010), which describe a worldwide accepted safety level for wind turbines. The consideration of the safety requirements described in these standards can help manufacture and operate a wind turbine according to the Machine Directive and legal requirements.

Annex VII, part B of the 2006/42/EG directive describes which technical documentation must be created:

- A plan of the entire machine and its controlling plans
- A list of basic requirements of this guideline, a list of standards, a list of other technical specifications that have been taken into consideration during manufacturing of the machine
- Operating instructions
- EC Declaration of Conformity
- Declaration of incorporation and assembly instructions (if necessary)
- Risk assessment

A major part of this technical documentation can be determined from the risk assessment that has been done for the wind turbine. This risk assessment describes, e.g., usage limits (correct use, incorrect use) time limits (service life, maintenance intervals), physical limits (space requirements for maintenance staff), further limits (temperature ranges) and the requirements for the functional safety of the plant considering all danger areas. The development and construction of mechanical, hydraulic, electrical and electromechanical control components as well as programmable controllers have to be considered. This process is described in the DIN EN ISO 13849-1 standard and can be applied to wind turbines as there is no updated C standard (machine safety standard) for this kind of machines. As the DIN EN ISO 13849-1 standard is one of the harmonized European standards, it is applicable for giving the presumption of conformity for the Machine Directive. In this standard, the term Performance Level (PL a to PL e) is used, which specifies the capacity of the safety-related parts of a control system to execute a safety function under foreseeable conditions. This way, the risk assessment for the wind turbine can be used to specify which Performance Level can be applied in order to interpret a safety function according to DIN EN ISO 13849-1.

Phoenix Contact not only offers a wide range of safe switching devices and controllers for scalable solutions in the wind power sector, but also extensive and individual services by certified safety experts. These services are based on the safety lifecycle of machines. Our specialist team supports you with training, workshops, engineering services or individual advice during project planning and the implementation of safety-related functions. Within the framework of moderation, we accompany our customers through the individual phases of the safety lifecycle of machines. This way, for example a complete risk assessment of a wind turbine can be implemented in cooperation with our specialists.