Large machinery - Safely-Limited Position

 

Task

Absolute encoders and mechanical limit switches (levers and/or rotary limit switches) characterize state-of-the-art solutions for position detection and limiting the end position of moving system components on large machinery in open-cast mining applications. To ensure the safety of personnel and safeguard machinery it is essential that limit switches are reliably actuated when the end position is reached. Consequently, highly reliable monitoring technology is necessary to comply with the corresponding safety requirements – in particular when implementing upgrades or automation measures. To meet the required performance level, two-channel architectures or diverse redundant systems are needed.

 

Huebner Solution

The universal encoder system U-ONE®-SAFETY-Compact consists of a basic unit and directly attached switch or bus modules. All functions are integrated in a robust casing that has been designed to meet the specific demands of heavy industry. Safety switching signals are issued according to position and speed based on a 13/15 bit resolution (max. 32768 rotations). It is possible to combine diverse bus interfaces as well as a 4 - 20 mA analog output or an incremental output according to application requirements. As a consequence, it is possible to replace several individual devices with a single compact device. The system-wide two channel architecture facilitates the implementation of safety functions up to Category 3 and Performance Level (PL) d as well as SIL 2.