AS/NZS 61439:2026 — What's Actually Changed for Switchboard Design, Verification and Compliance (and What It Means Before the Feb 2027 Deadline)"

Published February 2026 · Applies from 20 February 2027 (Part 1)

New editions of AS/NZS 61439.1 and AS/NZS 61439.2 — the standards governing the design, construction and verification of low-voltage switchgear and controlgear assemblies (switchboards) — were published in February 2026, superseding the 2016 editions. They're modified adoptions of IEC 61439-1 and IEC 61439-2, Edition 3.0 (2020), with Australian national variation boxes added on top.

If you design, specify, review or sign off switchboards in Australia, this update changes some of the fundamentals around temperature-rise verification, shock protection classification, and how variable speed drives, UPS units and switch-mode power supplies are treated inside an assembly. Here's a plain-English breakdown of what's changed and what it means for your next project.

QUICK REFERENCE: 2016 EDITION VS 2026 EDITION

Standard part covered
2016: Part 1 (General rules), Part 2 (Power switchgear)
2026: Same structure, both parts revised — Part 1 published 20 Feb 2026, Part 2 published 13 Feb 2026
Why it matters: Both parts need re-checking, not just one

VSDs, UPS, SMPS, converters inside an assembly
2016: Treatment of how these devices sit inside an assembly was a grey area — tested to their own product standard, but incorporation rules weren't explicit
2026: Explicitly clarifies these devices are tested to their own particular product standard, but their incorporation into the assembly must comply with the 61439 series
Why it matters: Removes ambiguity over who's responsible for compliance when a VSD or UPS is built into a switchboard

Temperature-rise verification
2016: Based on assembly rated current as a whole
2026: Introduces a "group-rated current" for circuits within a loaded assembly, and refocuses temperature-rise verification around that new characteristic
Why it matters: Changes how you calculate and verify heating in multi-circuit assemblies — particularly relevant for MSBs with mixed loading

Shock protection classification
2016: Not classified this way
2026: Introduces Class I and Class II assembly classification for protection against electric shock
Why it matters: New classification language will likely start appearing in switchboard schedules and spec call-ups

Forms of internal separation
2016: Existing Form 1–4 separation requirements (Part 2)
2026: Clarifies requirements for forms of separation, and adds: where separation is greater than Form 1, all parts that remain live when a functional unit is switched off must be protected to at least IPXXB
Why it matters: Directly affects internal layout and barrier design for withdrawable/removable units

PV (solar) installations
2016: No dedicated annex
2026: New annexes (DD, EE, FF) add specific requirements for assemblies used in PV installations
Why it matters: Relevant if your scope includes solar inverter switchboards or embedded generation switchrooms

Temperature rise — high current / cooling method
2016: Verification methods geared to lower current thresholds
2026: Adds temperature-rise verification requirements for naturally cooled assemblies above 1600 A, and actively cooled assemblies rated up to 1600 A
Why it matters: Matters for large MSBs and forced-ventilation switchrooms — check which verification method your board falls under

External surface temperature
2016: Not separately addressed
2026: Additional requirements to limit the temperature rise of externally accessible surfaces (Clause 11)
Why it matters: Relevant to touch-safety on enclosure exteriors, especially outdoor/plant-room boards

Date of application
2016: N/A
2026: Part 1: 20 February 2027
Why it matters: Existing boards verified to the 2016 edition remain compliant with that edition — this is not retroactive

WHAT THIS MEANS IN PRACTICE

1. Grey areas around embedded VSDs and UPS units are closing
   If your switchboard design incorporates a variable speed drive, UPS, or switch-mode power supply, the new standard is explicit: the device itself is tested to its own product standard, but how it's integrated into the assembly — clearances, thermal management, protection coordination — is governed by AS/NZS 61439. This removes a long-running point of disagreement between switchboard builders and device suppliers over where responsibility sits.

2. Temperature-rise verification is more nuanced
   The old approach to verifying temperature rise treated the assembly's rated current fairly broadly. The new "group-rated current" concept means verification is now more specific to how circuits are actually loaded together within the assembly — which is a more realistic reflection of how boards operate in the field, but does mean design engineers need to revisit how they specify and verify multi-circuit boards.

3. New Class I / Class II language will start appearing in specs
   Expect switchboard schedules, tender documents and compliance certificates to start referencing Class I and Class II assemblies once the new edition beds in. Worth flagging to clients now so they're not caught off guard when a supplier's compliance paperwork starts using different terminology.

4. Separation and IPXXB requirements affect internal layout
   Where a form of separation greater than Form 1 is specified, live parts inside a functional unit compartment must now be protected to at least IPXXB when that unit is switched off. This has practical implications for barrier design and access covers on withdrawable and removable units.

5. Solar/PV switchboards now have a dedicated pathway
   The new Annexes DD, EE and FF in Part 2 give PV-connected assemblies their own specific requirements, rather than relying on general-purpose clauses. Useful if embedded generation or solar inverter switchrooms are part of your scope.

WHAT YOU DON'T NEED TO DO IMMEDIATELY
Assemblies already verified under the 2016 edition remain compliant with that edition — this change isn't retroactive. The practical trigger points are new designs, major switchboard replacements, and any project timeline that runs past the application date, where a client or certifier may reasonably expect the 2026 edition to apply.

A NOTE ON ACCURACY
This summary is based on published compliance bulletins and industry commentary on the new editions, not a clause-by-clause read of the purchased standard itself. Before using this as the basis for a design decision or compliance sign-off, verify the specific clause wording against your own copy of AS/NZS 61439.1:2026 and AS/NZS 61439.2:2026 (available from the Standards Australia store), particularly around the group-rated current definition and the exact IPXXB clause reference.