IEC 61936-1:2021 is the third edition of the international standard that provides common rules for the design and erection of electrical power installations in systems exceeding 1 kV AC and 1.5 kV DC. This version, published by the International Electrotechnical Commission (IEC) , supersedes the 2010 edition and introduces major technical updates to align with modern engineering practices and safety protocols.
| Area of Change | Key Improvements | |---|---| | | The scope has been improved to clarify the document's application | | Terms and Definitions | Missing and obsolete terms have been updated, including improvement of existing terms | | Table 1 (Supplier-User Agreements) | Updated to identify where agreements between supplier and user are needed | | Electromagnetic Compatibility (EMC) | Requirements for EMC have been clarified | | Insulation Coordination (Clause 5) | Improved wording for better clarity; technical content updated to the latest versions of insulation coordination standards | | Electrical Equipment | Wording regarding electrical equipment has been improved and made clearer | | Fuses | Subclause for fuses has been improved and reworded | | Labelling for Multiple Sources | Requirements added for labelling when multiple sources must be disconnected | | Gas-Insulated Switchgear (GIS) | Missing requirements for GIS have been reintroduced | | Ventilation (HVAC) | Subclause regarding ventilation has been improved | | Transformer Installations | Requirements improved, including editorial typing-error corrections | | Protection, Automation, and Auxiliary Systems | Clause restructured and improved | | Lightning Protection | Protection against lightning strokes has been extended | | Safe Working Procedures | Distinction clarified between erection (and providing electrical safety for intended use) and subsequent activities such as maintenance and repair with safe working procedures | | Safe Working Guidelines (Annex F) | Where no provincial, national, or regional regulations are available for safe working procedures, an informative guideline is provided in Annex F |
. This third edition is the primary international standard for the design and erection of AC electrical power installations with nominal voltages exceeding Key Technical Updates in the 2021 Edition
| National Representative | Country/Region | |---|---| | | Canada | | NBN | Belgium | | BSI | United Kingdom | | EVS | Estonia | | NSAI | Ireland | | AFNOR | France | | DIN | Germany | | JSA | Japan | iec 6193612021 link
: Requirements for GIS (Gas-Insulated Switchgear) and transformer installations have been reintroduced or improved.
To obtain the standard, contact official IEC national committee members or authorized distributors:
Knowing your project type will allow me to provide more tailored technical snippets. IEC 61936-1:2021 is the third edition of the
While the document focuses on AC systems, it clarifies the boundaries where it intersects with DC installation standards, ensuring no "gray areas" exist in hybrid power complexes. Technical Scope The standard applies to:
Following IEC 61936-1:2021 is not just a best practice—it is often a legal requirement in many jurisdictions. In Australia, for example, the draft is based on this 2021 international standard.
Do you need help calculating specific parameters like or transformer fire separation distances ? This third edition is the primary international standard
High altitudes require derating of insulation properties due to thinner air.
IEC 61936-1:2021 has been adopted as a (EN IEC 61936-1:2021) and is therefore mandatory in all CENELEC member countries. Many national standards bodies have published identical national versions:
: Transmission and distribution switching substations, including those powering railway grids.