IEC 61472-2-2021 PDF

Full title and description

St IEC 61472-2-2021 — Live working - Minimum approach distances - Part 2: Method of determination of the electrical component distance for AC systems from 1,0 kV to 72,5 kV. This international standard specifies a calculated method to determine the electrical component of minimum approach distances (air gap required to avoid disruptive discharge) applicable to live working on AC systems with nominal voltages from 1.0 kV up to and including 72.5 kV; it addresses system overvoltages, required withstand voltages and working air distances between equipment and/or workers at different potentials.

Abstract

IEC 61472-2:2021 provides a formula- and data-based method to derive the electrical distance (the component of minimum approach distance that prevents flashover) for medium-voltage AC systems (1.0 kV to 72.5 kV). It is intended to be used where transient overvoltages govern the dielectric stress, and only under defined working conditions (trained personnel, controlled overvoltage statistics, dry tool insulation, no nearby lightning, and allowance for conducting tool components).

General information

• Status: Published / Active
• Publication date: 9 March 2021
• Publisher: International Electrotechnical Commission (IEC)
• ICS / categories: 13.260 (Protection against electric shock. Live working); 29.240.99; 29.260.99
• Edition / version: Edition 1.0 (2021)
• Number of pages: 32 (bilingual English/French edition)

Core bibliographic and status details per IEC publication data.

Scope

This part of IEC 61472 specifies a method for determining the electrical component of minimum approach distances for live working on AC systems with nominal voltages from 1.0 kV up to and including 72.5 kV. The document covers selection of statistical and transient overvoltage values, calculation of required withstand voltages, and the translation of those voltages into working air distances; it also defines the working conditions under which the calculated distances and withstand voltages are valid.

Key topics and requirements

• Definition and decomposition of minimum approach distance into electrical and ergonomic components.
• Method to determine the electrical component distance (DA) for AC systems 1.0 kV to 72.5 kV.
• Selection and treatment of statistical and transient overvoltages used to derive required withstand voltages.
• Conversion of required withstand voltages to air-gap distances, including atmospheric/altitude considerations and gap/gap-factor parameters.
• Assumptions and limiting working conditions (trained/skilled workers, dry tool insulation, no lightning within 10 km, allowance for conducting tool parts).
• Guidance on when the method applies and when further site-specific evaluation or testing is necessary.
• Informative annexes and examples to support practical application (worked examples, dielectric strength considerations and factors influencing calculations).

Typical use and users

Primary users include electrical utilities, power distribution designers, live-line crews and supervisors, safety managers, occupational health and safety professionals, equipment designers, and regulators. The standard is used to set safe working distances, inform tool and PPE specifications for live work, support safe work procedures, and to harmonize distance/withstand calculations across organizations performing live work on medium-voltage AC systems.

Related standards

IEC 61472-2:2021 complements the broader IEC 61472 family; IEC 61472 (2013) covers minimum approach distances and calculation methods for higher voltages (72.5 kV to 800 kV). Other related TC 78 live-working standards address tools, gloves, insulating devices and terminology (for example IEC 60900, IEC 60903, IEC 61243 series, IEC 60743, IEC 61318 among others) and provide equipment, testing and terminology guidance that integrates with the approach-distance methodology.

Keywords

live working; minimum approach distance (MAD); electrical distance; withstand voltage; medium voltage; 1 kV–72.5 kV; overvoltages; dielectric strength; TC 78; safety distances; insulating tools

FAQ

Q: What is this standard?

A: IEC 61472-2:2021 is Part 2 of the IEC 61472 series; it specifies a method to determine the electrical component of minimum approach distances for live working on AC systems from 1.0 kV to 72.5 kV.

Q: What does it cover?

A: It covers selection of overvoltage values, calculation of required withstand voltages, and conversion of those voltages into working air distances under defined working conditions (e.g., trained personnel, dry tools, absence of nearby lightning).

Q: Who typically uses it?

A: Utilities, live-line crews and supervisors, safety and compliance teams, designers of live-work procedures and equipment manufacturers use the standard to set safe working distances and to inform tool and PPE specifications.

Q: Is it current or superseded?

A: IEC 61472-2:2021 was published on 9 March 2021 and is the current Part 2 publication for the specified voltage range; IEC indicates a stability period for the publication (see IEC bibliographic data). Users should check national implementations or amendments that may apply locally.

Q: Is it part of a series?

A: Yes — it is Part 2 of the IEC 61472 series (minimum approach distances for live working). Part(s) and earlier editions of IEC 61472 address other voltage ranges (for example the 2013 edition covering 72.5 kV to 800 kV) and the series is maintained by IEC TC 78 (Live working).

Q: What are the key keywords?

A: live working, minimum approach distance, electrical distance, withstand voltage, medium voltage, overvoltage, dielectric strength.