IEC 61850-7-4 Splits Into Seven Parts: Committee Drafts Open for Public Comment Until April 10

IEC TC 57 Working Group 10 published seven Committee Draft for Vote (CDV) documents on February 13, 2026, proposing to replace the monolithic IEC 61850-7-4 with a family of seven modular parts. The models themselves are not changing — only their structural organisation. Engineers and national committee members can submit public comments until April 10, 2026.

Seven Documents, One Restructuring

The seven CDVs carry document numbers 57/2870 through 57/2876 and cover the following new parts:

The naming convention follows a deliberate hierarchy: 7-4 is the core, 7-4n (7-40, 7-43, 7-44) designates first-level subdomains, and 7-4nn (7-400, 7-401, 7-440) designates second-level specialisations.

No Changes to the Models

The restructuring is structural, not technical. Christoph Brunner, convener of WG10 and author of the Edition 2025 initiative, is explicit on this point:

"For Edition 2025, there will be no changes to the models themselves — the only change is the way they are represented."

— Christoph Brunner, PAC World

Logical node classes, data objects, and attributes defined in IEC 61850-7-4 Edition 2.1 carry over unchanged. The split does not introduce new LN models or modify existing ones.

Why the Split

The motivation, as described by Brunner across two PAC World columns, is operational agility:

• Independent updates per domain. A change in protection LN models (7-401) will no longer require republishing the entire 7-4 document.
• Faster conformance testing. Test suites can be scoped to individual parts rather than the full monolithic document.
• Scalability for new domains. Adding new application areas becomes a matter of publishing a new sub-part rather than amending a single large document.

This approach was outlined in the WG10 roadmap document 57/2744/INF, published December 6, 2024.

Namespace Evolution

The new IEC 61850-7-4 ED3 includes a new Appendix G — Namespace Evolution — which documents how the namespace structure changes as a result of the split from Edition 2.1. WG10 identifies edition versions by year (hence "Edition 2025"), and the namespace reflects that convention.

Part 6 (SCL): One Related Change

In parallel with the 7-4 restructuring, WG10 is preparing an updated edition of Part 6 (SCL) in which the XML schema will be generated automatically from a UML model. Brunner notes that the semantics will remain identical, though the schema's textual form may differ from the current one.

How to Comment Before April 10

The CDV stage is one of the few points in the IEC standards process where comments from outside national committees can reach the drafting group.

Public comments can be submitted at: 👉 https://www.iec.ch/how-get-involved/public-commenting

National committee members (P-members) can submit formal comments via the IEC OSD platform: 👉 https://knowledge.iec.ch/osd-submit-national-comments

Deadline: April 10, 2026.

Comments received at this stage inform WG10 before the documents proceed to final voting. Engineers working with IEC 61850 conformance testing, tool development, or domain-specific LN models have a direct stake in how the split is implemented.

Sources

1. Seven IEC 61850 Model Documents Published for Public CDV Comments — NettedAutomation (2026-02-13)
2. Edition 2025 of IEC 61850 — Christoph Brunner, PAC World
3. An Update from WG10 — Christoph Brunner, PAC World
4. IEC TC 57 Votes — Document numbers 57/2870–57/2876/CDV
5. IEC: How to Get Involved — Public Commenting
6. IEC CDV Commenting Guide
7. NettedAutomation February 2026 Archive