IEC 60077-4:2019

Overview

IEC 60077-4:2019 - "Railway applications - Electric equipment for rolling stock - Part 4: Electrotechnical components - Rules for AC circuit-breakers" is the 2019 (Edition 2.0) product standard that specifies rules for AC circuit-breakers whose main contacts connect to AC overhead contact lines (nominal voltages per IEC 60850). It updates and supplements IEC 60077-2 and defines characteristics, service conditions, test methods and product information required to verify compliance of electrotechnical components used in rolling stock.

Key topics and requirements

• Scope and applicability: Rules for AC circuit-breakers used in railway rolling stock where main contacts are connected to AC overhead contact lines.
• Component characteristics: Definition of rated and limiting values for voltages, currents, frequencies, power factors and short‑circuit behaviour.
• Service conditions: Requirements covering operation and behaviour in normal service, operation under short‑circuit conditions, and dielectric properties.
• Testing and verification:
  • Type tests, routine tests and investigatory tests to confirm compliance.
  • Test sequences covering general performance, short‑circuit making/breaking capability, vibration/shock, transient recovery voltage and climatic conditions.
  • Recent technical changes include a review of standard transient recovery voltage (TRV) values and test procedure, revised temperature‑rise verification, and addition of air‑tightness type tests and insulation resistance measurements.
• Construction and performance: Requirements for clearances, creepage distances, EMC, acoustic noise, temperature rise limits and mechanical endurance.
• Marking and documentation: Information that must be marked on or supplied with the circuit‑breaker for identification and safe use.

Practical applications and users

Who uses IEC 60077-4:2019:

• Rolling stock designers and electrical engineers specifying AC circuit-breakers for locomotives, EMUs and coaches.
• Manufacturers and suppliers developing, testing and certifying electrotechnical components.
• Test laboratories and certification bodies performing type and routine tests to demonstrate compliance.
• Procurement and maintenance teams needing clear requirements for documentation, marking, and in-service behaviour under normal and fault conditions.

How it’s used:

• As the basis for technical specifications, acceptance tests and conformity assessment for AC circuit-breakers in railway projects.
• To define required making/breaking capacities, TRV performance, dielectric withstand and environmental robustness for rolling stock components.

Related standards

• IEC 60077-1 - General rules for electric equipment for rolling stock (reference for general conditions).
• IEC 60077-2 - Electrotechnical component general rules (supplemented by Part 4).
• IEC 60850 - Defines nominal voltages of AC overhead contact lines referenced by this standard.

Keywords: IEC 60077-4:2019, AC circuit-breakers, railway applications, rolling stock, transient recovery voltage, temperature rise, air-tightness test, insulation resistance, type tests, electrotechnical components.