Functionally safe limit switch for safe motion monitoring of axis rotation in wind turbines and other large machines.

FSI 900 YAWMO® is a position sensor with integrated functionally safe limit switch, developed for the yaw (azimuth) motion monitoring of the wind turbine nacelle. High availability and minimized time for standstill is not only an economic factor, but also important for safety. For some functions, unplanned or uncontrolled movements simply cannot be allowed to take place.

In many applications where functionally safe motion monitoring is necessary with regard to the machinery directives, for example RTG cranes, mobile cranes and conveyor belts, Leine Linde's FSI 900 solutions are used. YAWMO® is a registered trademark for Leine Linde's position sensor products supplied with customized pinion wheel mounting, which is very appreciated when monitoring large axis rotation.

Functionally safe yaw motion monitoring

Functionally safe monitoring of the wind turbine's yaw system or other angle position movements is made by the FSI 900 YAWMO®, based on the Leine Linde's FSI 900 series. The product is a failsafe high-resolution position sensor based on an encoder with integrated electronic limit switch and fieldbus interface for communication. It is built with separate safety channels (in-and output) and safe relay connection for disconnecting the safety supply. This is used for example in case of risk for exceeding the yaw twist limit in order to ensure a safe state of the windmill. 

One channel is optionally used for turbine controller monitoring of relay state and the other channel can be the contactor part for the safety loop.

FSI 900 YAWMO® uses inductive scanning for safe position monitoring and is designed and certified in compliance with SIL 2, category 3. The fault-proof relays are integrated with the product, which decreases the installation time as well as the risk of cable wear, since extra relays and cabling is no longer needed. There is less manual labour required on site to achieve a secure system.  

The modular design of the sensor offers easy customization to match the wind turbine design and allows the use of a backlashed, customer-specific gear for optimized system resolution and turbine control. Software is included which enables the customer to make custom configurations and carry out device monitoring and diagnostics. The exact position and other information can be queried at any time.

Technical data

Enclosure Anodized aluminium
Mounting brackets Aluminium, steel, stainless steel
Temperature –30°C … +70°C
Operating height Max. 3000 m
Protection class IP67
Voltage supply 18 … 30 Vdc
System resolution 19 bit single-turn, 12 bit multi-turn
Communication interfaces PROFINET
Lifetime up to 25 years
Safety features Safe cam, safety limited acceleration, additional safety features
Safety certificates SIL 2 (IEC 61508), PLd, Cat. 3 (DIN EN ISO 13849)
Configuration PC software or preconfigured upon delivery
Contact us