EN 50491-2 General requirements for Home and Building Electronic Systems (HBES) and Building Automation and Control Systems (BACS) – Part 2: Environmental conditions – This European Standard provides the environmental conditions for all devices connected to HBES/BACS. This European Standard is applicable (but not limited) to – operator stations and other human system interface devices, – devices for management functions, – control devices, automation stations and application specific controllers, – field devices and their interfaces, – cabling and interconnection of devices, – dedicated devices for engineering and commissioning tools for HBES/BACS. The standard defines the general requirements for devices operating in weather protected and non-weather protected locations, ship environments, portable use and also for storage and transport.