EN 50122: Ensuring Electrical Safety on Railways Worldwide
EN 50122 standardizes railway electrical safety, focusing on traction current and protective measures to ensure safe rail operations worldwide.

Introduction to EN 50122
EN 50122 is a European standard that defines electrical safety requirements for railway systems. It primarily addresses protective measures against electric shock and ensures the safe operation of traction power networks and signaling equipment.
Scope and Purpose
The standard provides guidelines for the design, installation, and maintenance of railway electrical systems, including protective earth, insulation, and traction current management. Its primary goal is to prevent accidents and ensure the safety of personnel, passengers, and infrastructure.
Key Components
- Protective Measures: Ensures safe grounding, insulation, and fault current management.
- Traction Current: Standardizes safe voltage limits and current return paths for trains.
- Signaling Safety: Integrates electrical safety with signaling and interlocking systems.
- Maintenance Guidelines: Defines procedures for inspection, testing, and fault handling.
Comparison Table
| Parameter | EN 50122 Requirement | Typical Practice |
|---|---|---|
| Protective Earth Resistance | < 1 Ω | < 2 Ω |
| Touch Voltage Limit | 50 V DC / 25 V AC | 60 V DC / 30 V AC |
| Insulation Testing Interval | Every 12 months | Every 24 months |
Implementation and Benefits
EN 50122 is adopted by railway operators across Europe and internationally to standardize electrical safety. Its implementation reduces accident risk, protects equipment, and ensures reliable rail service, especially in electrified and high-speed lines.
Snippet Bait
EN 50122 defines critical electrical safety standards for railways, covering traction current, protective measures, and signaling integration to protect people and infrastructure.





