BS EN 50122-1:2022+A1:2025

This standard BS EN 50122-1:2022+A1:2025 Fixed installations for railway applications. Electrical safety, earthing and the return circuit is classified in these ICS categories:

• 29.120.50 Fuses and other overcurrent protection devices
• 29.280 Electric traction equipment

This document specifies requirements for the protective provisions relating to electrical safety in fixed installations associated with AC and/or DC traction systems and to any installations that can be endangered by the electric traction power supply system. This also includes requirements applicable to vehicles on electrified lines. It also applies to all aspects of fixed installations which are necessary to ensure electrical safety during maintenance work within electric traction power supply systems. This document applies to new electric traction power supply systems and major revisions to electric traction power supply systems for: a) railways; b) guided mass transport systems such as 1) tramways, 2) elevated and underground railways, 3) mountain railways, 4) trolleybus systems, 5) electric traction power supply systems for road vehicles, which use an overhead contact line system, and 6) magnetically levitated systems, which use a contact line system; c) material transportation systems. This document does not apply to: a) electric traction power supply systems in underground mines, b) cranes, transportable platforms and similar transportation equipment on rails, temporary structures (e.g. exhibition structures) in so far as these are not supplied directly or via transformers from the contact line system and are not endangered by the electric traction power supply system, c) suspended cable cars, d) funicular railways, e) existing vehicles. This document does not specify working rules for maintenance. The requirements within this document related to protection against electric shock are applicable to persons only.