PD IEC/TR Standards Single-File Series Overview — A Compilation of 135 IEC Technical Reports (IEC/TR) and Their Technical Points

PD IEC/TR is the British standard publication formed when the UK adopts the Technical Report (TR) published by the International Electrotechnical Commission (IEC), published by BSI. IEC/TR is an important informative document in the IEC standards system, used to provide application guidance, summary of test results, technical explanations and directional research; its content is largely informative or guidance in nature and does not carry the binding force of standard clauses. This batch compiles 135 single-file PD IEC/TR standards covering insulation co-ordination, short-circuit currents, functional safety, optical fibres and cables, HVDC transmission, electromagnetic compatibility, medical electrical equipment, automation systems, secondary batteries and electric vehicles, and nuclear power plant instrumentation and control.

These technical reports provide important support for the application of full IEC standards (IS) in real engineering, helping engineers understand standard intent, select parameters and correctly implement tests. This article is organised into six parts: series overview, standard list, key technical requirements, representative standard interpretation, engineering practice and application, and frequently asked questions.

1. Series Overview 📌

IEC/TR technical reports are prepared by IEC technical committees to provide application support and background information for the corresponding full IEC standards (IS). Technical reports typically contain guidance, case studies, summary of test results, terminology explanations and technical development directions, helping users execute formal standards more accurately and effectively. The 135 technical reports in this batch are adopted and published by BSI as the PD IEC/TR series.

By content nature, this batch can be divided into: application guidance types (e.g. IEC TR 60269-5 application guide for low-voltage fuses, IEC TR 61916 harmonization of electrical accessories, IEC TR 62691 installation of optical fibre cables), calculation method types (e.g. IEC TR 60909-2 data for short-circuit current calculations in three-phase a.c. systems, IEC TR 60865-2 examples of calculation of short-circuit current effects, IEC TR 62095 cable current rating calculations using finite elements), safety and environment types (e.g. IEC TR 60479-4 effects of lightning strokes on human beings and livestock, IEC TR 62222 fire performance of communication cables in buildings, IEC TR 62757 fire prevention measures on HVDC converters), medical electrical types (e.g. IEC TR 62354 general testing procedures for medical electrical equipment, IEC TR 62366-2 guidance on application of usability engineering) and topic research types (e.g. IEC TR 62778 application for assessment of blue light hazard, IEC TR 62660-4 candidate test methods for internal short circuit of lithium-ion cells, IEC TR 62874 markers of paper thermal degradation in insulating oil).

This application-support-oriented positioning makes IEC/TR an important bridge connecting standard clauses with engineering practice.

2. Standard List and Technical Points 📋

3. Key Technical Requirements 🔧

In insulation co-ordination and electrical calculation, IEC TR 60071-4 provides a computational guide to insulation co-ordination and modelling of electrical networks, IEC TR 60909-2 collects equipment data needed for short-circuit current calculations, IEC TR 60865-2 provides examples of calculation of thermal and mechanical effects of short-circuit currents, and IEC TR 62095 provides cable current rating calculations using finite elements.

In fuses and low-voltage switchgear, IEC TR 60269-5 provides an application guide for low-voltage fuses, IEC TR 62655 provides a tutorial and application guide for high-voltage fuses, IEC TR 61439-0 provides guidance to specifying assemblies of low-voltage switchgear and controlgear, and IEC TR 61641 specifies guidance for testing assemblies under conditions of arcing due to internal fault.

In optical fibres, IEC TR 62221 specifies microbending measurement methods, IEC TR 62283 provides guidance for nuclear radiation tests on optical fibres, IEC TR 62349 provides guidance of measurement methods for polarization-maintaining optical fibres, IEC TR 62690 provides research on hydrogen effects in optical fibre cables, and IEC TR 62691 provides guidelines for installation of optical fibre cables.

In medical electrical, IEC TR 62366-2 provides guidance on the application of usability engineering to medical devices, IEC TR 62354 specifies general testing procedures for medical electrical equipment, and IEC TR 60878 provides graphical symbols for electrical equipment in medical practice.

In EMC and human exposure, IEC TR 62630 provides guidance for evaluating exposure from multiple electromagnetic sources, IEC TR 62493-1 summarises the results of an EMF measurement campaign for lighting equipment, IEC TR 62778 provides the application of IEC 62471 for assessment of blue light hazard to light sources and luminaires, and IEC TR 62669 provides case studies supporting the evaluation of RF field strength near radiocommunication base stations.

4. Representative Standard Interpretations 🔍

PD IEC/TR 62778:2014 Application of IEC 62471 for the assessment of blue light hazard to light sources and luminaires

Scope: This technical report provides application procedures and interpretation of IEC 62471 for assessing blue light hazard of light sources and luminaires, and is an important reference for photobiological safety assessment of lighting products.

Key points: The report explains the relevant concepts of blue light hazard in the photobiological safety standard IEC 62471, including definitions of radiometric quantities, application of spectral weighting functions and classification of hazard categories, and provides methods for transferring the hazard level of a light source to that of a luminaire. The report particularly clarifies the relationship between ‘RG’ categories, colour temperature and luminance, helping lighting designers and test laboratories apply the standard correctly and avoid over- or under-protection.

PD IEC/TR 62660-4:2017 Secondary lithium-ion cells for the propulsion of electric road vehicles — Part 4: Candidate alternative test methods for the internal short circuit test of IEC 62660-3

Scope: This technical report presents candidate alternative test methods for the internal short circuit test of lithium-ion cells for electric vehicles, as a supplement to IEC 62660-3.

Key points: The report reviews the limitations of internal short circuit tests (such as nail penetration and crush), presents candidate methods based on local heating, metal particle inclusion and mechanical deformation as triggering approaches, and discusses the repeatability and representativeness of each method. The report provides technical input for subsequent revision of battery safety standards, helping manufacturers and test laboratories assess internal short circuit risk more realistically.

PD IEC/TR 62366-2:2016 Medical devices — Part 2: Guidance on the application of usability engineering to medical devices

Scope: This technical report provides guidance on applying usability engineering (human factors engineering) to the design, evaluation and improvement of medical devices, supporting the implementation of IEC 62366-1.

Key points: The report explains the basic usability engineering process, including user and use-environment analysis, use-risk identification, usability verification and validation, design modifications and documentation, and provides differentiated implementation recommendations for devices of different risk levels. The report emphasises identification and control of use error as a source of risk, helping medical device manufacturers meet regulatory requirements on human factors.

PD IEC/TR 60909-2:2008 Short-circuit currents in three-phase a.c. systems — Part 2: Data of electrical equipment for short-circuit current calculations

Scope: This technical report compiles electrical data of equipment needed for short-circuit current calculations in three-phase a.c. systems, supporting the application of IEC 60909-0.

Key points: The report compiles electrical data of equipment needed for short-circuit current calculations, including source impedances, transformer data, generator data, line and cable impedances and motor contributions, with typical values and calculation guidance. These data enable engineers to perform short-circuit current calculations accurately in the design of power systems, switchgear and protection, ensuring equipment ratings and protective device settings are appropriate.

PD IEC/TR 62757:2015 Fire prevention measures on converters for high-voltage direct current (HVDC) systems, static var compensators (SVC) and flexible ac transmission systems (FACTS) and their valve halls

Scope: This technical report summarises fire prevention measures for high-voltage direct current converters, static var compensators (SVC) and flexible AC transmission systems (FACTS) and their valve halls.

Key points: The report analyses fire risk sources in converter station valve halls, including cooling system leakage, electrical faults, insulation ageing and external fire sources, and provides a full set of prevention measures covering design selection, material choice, monitoring and alarm, and fire-fighting systems. It emphasises the particularity of valve halls as enclosed high-voltage areas, requiring fire protection design to balance electrical safety, personnel safety and system availability, and is an important reference for converter station engineering design.

5. Engineering Practice and Application 🛠️

In lighting product compliance, IEC TR 62778 is used by test laboratories and manufacturers to transfer the blue light hazard level of a light source to luminaires, assess the photobiological safety category and prepare compliance documentation.

In power system design, IEC TR 60909-2 and IEC TR 60865-2 are used for short-circuit current calculations and equipment selection, ensuring safe operation of switchgear, busbars and protective devices under fault conditions.

In battery safety assessment, the candidate test methods of IEC TR 62660-4 are used for research-oriented evaluation of internal short circuit risk, providing input to product development and standard revision.

In medical device development, IEC TR 62366-2 is used to conduct usability engineering studies, identify use errors and improve design, supporting the human factors documentation for product registration.

In optical fibre network engineering, IEC TR 62221 and IEC TR 62691 are used for microbending measurement and installation quality control of optical cables, ensuring optical transmission performance.

6. Frequently Asked Questions ❓