IEC 62271-104:2020

Overview

IEC 62271-104:2020 is an international standard developed by the International Electrotechnical Commission (IEC) that specifies requirements for high-voltage alternating current (AC) switches rated for voltages above 52 kV. This standard applies to three-pole AC switches intended for indoor and outdoor installations and rated for frequencies up to and including 60 Hz. The 2020 edition, being the third edition, replaces the 2015 second edition and introduces a technical revision with updated numbering in accordance with IEC 62271-1:2017.

The standard ensures safety, reliability, and interoperability of high-voltage switches used in power transmission and distribution networks. It covers the definition, ratings, design criteria, testing procedures, and operational guidelines for high-voltage AC switches.

Key Topics

• Scope and Applicability
  IEC 62271-104:2020 covers three-pole AC switches for rated voltages higher than 52 kV, ensuring compatibility with varied installation environments, including indoor and outdoor settings. The rated frequency limit is 60 Hz.

• Ratings and Performance
  Detailed rated values are specified, including rated voltage, rated insulation levels (power-frequency withstand voltage, lightning impulse withstand voltage), continuous current, short-time withstand current, peak withstand current, making and breaking currents, and rated operational durations. These ratings define the performance limits under normal and fault conditions.

• Design and Construction Requirements
  The standard mandates requirements for materials (liquids, gases), earthing, auxiliary and control circuits, operation mechanisms (manual, independent, stored energy), locking devices, position indication, and degree of protection against environmental factors. It also addresses insulation coordination, electromagnetic compatibility (EMC), fire hazards, resistance to corrosion, and tightness for gas- and liquid-filled components.

• Testing Procedures
  Comprehensive type and routine tests are prescribed, including dielectric tests, radio interference voltage tests, continuous current tests, mechanical operations, making and breaking tests under capacitive and inductive load conditions, tightness, and EMC assessments. Testing ensures compliance with rated values and operational safety.

• Operational and Safety Guidelines
  Guidance on selecting appropriate switches based on rated values, environmental conditions, and service load is provided. The standard includes safety considerations, transport, storage, installation, operation, and maintenance instructions to support reliable switch operation.

Applications

IEC 62271-104:2020 is vital for manufacturers, designers, and operators of high-voltage switchgear systems in:

• Power Generation Plants
  For reliable switching of high-voltage circuits within power stations.

• Electrical Transmission Networks
  Enabling safe isolation and switching in high-voltage transmission lines rated above 52 kV.

• Distribution Substations
  Integration of high-voltage switches needed for controlling power distribution and fault isolation.

• Industrial High-Voltage Installations
  Important for industries requiring high-voltage infrastructure for process or production systems.

This standard ensures that switches meet stringent criteria to handle electric stresses, mechanical demands, and environmental challenges, minimizing downtime and enhancing grid stability.

Related Standards

IEC 62271-104:2020 aligns with and references other IEC standards that form the high-voltage switchgear framework:

• IEC 62271-1: General definitions for high-voltage switchgear and controlgear.

• IEC 62271-100: Specifications for high-voltage circuit-breakers.

• IEC 62271-105: AC disconnectors and earthing switches for voltages above 52 kV.

• IEC 60071: Insulation coordination standards critical for determining insulation levels in switchgear.

• IEC 60694: Common specifications for high-voltage switchgear structures.

Using these related standards in conjunction with IEC 62271-104 ensures cohesive and comprehensive implementation of high-voltage switching equipment in electrical networks.

Keywords: IEC 62271-104, high-voltage switches, alternating current switches, rated voltage above 52 kV, high-voltage switchgear standards, power transmission equipment, electrical switch testing, high-voltage controlgear, IEC high-voltage switchgear.