Powering the Rails: A Comprehensive Guide to EN 60077 Standards

What is EN 60077?

EN 60077 is the definitive series of European Standards specifying the general service conditions and general rules for all electrotechnical equipment installed in power circuits, auxiliary circuits, and control circuits on railway rolling stock.

Ensuring operational reliability in harsh railway environments, this standard dictates how electrical components—such as circuit breakers, contactors, and fuses—must perform under specific stresses. These stresses include voltage fluctuations, vibrations, extreme temperatures, and humidity. It is the European harmonization of the international IEC 60077 standard.

The Structure of the EN 60077 Series

The standard is divided into several parts, each addressing specific aspects of on-board electrical equipment. Understanding this hierarchy is essential for compliance and system integration.

• Part 1: General Service Conditions: Defines the environmental parameters (altitude, temperature, shock, and vibration) and general operational requirements.
• Part 2: Electrotechnical Components: General rules applicable to all components, covering design, construction, and testing.
• Part 3: DC Circuit Breakers: Specific rules for checking the breaking capacity and endurance of DC breakers.
• Part 4: AC Circuit Breakers: Specific requirements for AC switching devices.
• Part 5: High Voltage Fuses: Standards for fuses used in HV circuits on trains.

Key Operational Conditions Defined

One of the most critical aspects of EN 60077 is the definition of “Normal Service Conditions.” Equipment must be designed to withstand:

Voltage Variations: Rolling stock equipment must operate correctly within defined tolerances of the nominal catenary voltage (e.g., 70% to 125% of nominal voltage) as per EN 50163.
Environmental Factors: Components must function at altitudes up to 1400m (Class A1) or higher, and within temperature ranges typically spanning from -25°C to +40°C (Class T1) or more severe ranges (Class T3).

Quick Reference: EN 60077 Parts Summary