A wind turbine is by definition a functional machine that falls within the scope of the Machinery Directive (MD) and requires a declaration of conformity in accordance with Annex IIA. Several stand-alone machines that are arranged and controlled to function as an integral whole are also classified as machinery.
The PNOZmulti has been implemented in such wind turbine applications as it responds selectively to trigger devices and signals such as E-STOPs, vibration switches and limit value relays for speed, position and pressure. As the safety system reacts selectively to fault situations, it is possible to reduce forces and torques exactly at the point where they occur and are transmitted as extreme and continuous loads. The benefit is a considerable reduction in the mechanical wear of brakes and gears, for example, resulting in a longer service life.
Previous safety solutions on wind turbines have been based on a simple series connection of safety signals. Logically the reaction is always identical and the wind turbine is stopped hard. The mechanical design must be able to cope with these operating conditions. By using the PNOZmulti, with its differentiated reaction to various operational circumstances, it is possible to achieve a clear reserve of gondola and tower components. Servicing costs fall. Hazards are reduced. With the price of raw materials becoming increasingly expensive, the achievable cost reduction is a welcome, economic side effect.
The PNOZmulti safety system guarantees that the wind turbine is brought to a safe condition for both personnel and material, particularly in the case of a management failure or the failure of individual components.