EN 50491-3:2009

Introduction
1 Scope
2 Normative references
3 Definitions and abbreviations
4 Classification of HBES/BACS network interfaces
5 Safety requirements and compliance criteria
Annex A (normative) - Special national conditions
Bibliography

This European Standard provides the electrical safety requirements for all devices connected to HBES/BACS. This European Standard is applicable to –operator stations and other human system interface devices, –devices for management functions, –control devices, automation stations and application specific controllers, –field devices, –cabling and interconnection of devices. This European Standard covers the following requirements and compliance criteria: –protection from hazards in the device; –protection from overvoltages on the network; –protection from touch current; –protection from hazards caused by different type of circuits; –protection of the communication wiring from overheating caused by excessive current.