The recently withdrawn DIN EN ISO 13850 specified that an inactive, fixed emergency stop button had to be covered to prevent mix-ups in hazardous scenarios. Unfortunately, this was not always possible in practice, resulting in dangerous situations or even accidents. The standard has therefore been extended and now permits the use of active illuminated emergency stop buttons as an alternative. With its new QRBDUV actuator, Georg Schlegel GmbH & Co. KG, a global manufacturer of components for electrical and electronic control systems, has gone further than just implementing the expanded standard and added a number of extra safety features.
In addition to the yellow illuminated anti-lock collar on the emergency stop button, the QRBDUV actuator now also has an integrated diagnostic unit. This unit continuously monitors the button's illumination status and therefore functionality. If for any reason the light goes out, thus indicating that the actuator is inactive, a signal is automatically sent to the corresponding part of the plant, and production - including all modules, if they are connected in series - is stopped. "If the modular part of the plant is connected to the overall system, the active status of the emergency stop button is indicated by the light. If the connection is lost, the light on the actuator goes out and thus shows that the button is inactive," explains Kurt Blank, head of R&D at Schlegel. The company currently offers the QRBDUV emergency stop button for IP65 protection. Two versions are available - one as a kit, and the other as a plug-and-play solution. If customers opt for the kit, they can install all the components individually into the mounting plate. The plug-and-play version, however, is ideal for retrofitting, as the box can be easily installed using an M12 plug.