IEC 60077-2:2017

Overview

IEC 60077-2:2017 - Railway applications - Electric equipment for rolling stock - Part 2: Electrotechnical components – General rules - provides the general rules and uniform requirements for electrotechnical components used on railway rolling stock. This 2017 edition (Edition 2.0) adapts the high-level principles of IEC 60077-1 to the full range of components installed in power, auxiliary, control and indicating circuits on trains, trams and other rail vehicles.

Key updates in this edition include clarified requirements for:

• short circuit breaking capacity
• rated short-time withstand current
• critical currents range
• specification of climatic conditions

This standard is intended to be read in conjunction with IEC 60077-1 and is part of the IEC 60077 series for railway electric equipment.

Key Topics

• Scope and classification of electrotechnical components for rolling stock.
• Rated and limiting values: rated voltages, currents, time constants, and power factors relevant to AC/DC switchgear.
• Constructional requirements: terminals, bonding, connection capacity and marking.
• Performance requirements: temperature rise limits, dielectric strength, clearances and creepage distances, switching overvoltages.
• Operational capability: categories of components (A1–A4), operational performance and endurance.
• Short-circuit performance: breaking capacity, short-time withstand current and critical current ranges.
• Environmental and climatic conditions: specified service conditions and type/routine test sequences.
• Tests and verification: type tests, routine tests, test sequences I–VI (general performance, making/breaking capacities, vibration/shock, critical currents, climatic conditions, other tests).
• EMC, acoustic emission and mechanical resilience: requirements for electromagnetic compatibility, noise and ability to withstand vibration and shock.
• Documentation and marking: component documentation, storage/installation/maintenance instructions, and essential markings.

Applications

IEC 60077-2:2017 is used by:

• Manufacturers of railway electrotechnical components (switchgear, relays, auxiliary devices) for design and type testing.
• Railway system engineers and integrators specifying compliant components for rolling stock electrical systems.
• Test laboratories and certification bodies conducting type and routine testing per IEC sequences.
• Procurement and maintenance teams writing specifications, acceptance criteria and maintenance procedures to ensure safety, interoperability and reliability. Practical benefits include harmonized test methods, predictable performance under fault and climatic conditions, and clearer requirements for short-circuit and thermal endurance.

Related Standards

• IEC 60077-1:2017 - General rules (must be read in conjunction with Part 2).
• Other parts of the IEC 60077 series covering specific component types and system-level requirements.