Get a taste of what's new in NEK 400:2026
When NEK 400:2026 enters into force in July, the requirements for the electrical industry will be tightened. "Up-to-date understanding is crucial," says Edgar Karlsen, consulting electrical engineer at Lofoten Technical and course instructor at NITO.
Open course in NEK 400:2026 – New and updated requirements in the regulations
New requirements require more than quick lookups
Every time NEK 400 is updated, it has direct consequences for how electrical systems are designed, built and controlled," explains Edgar Karlsen. The changes in the 2026 edition are not only about new formulations in the regulations, but about how the requirements are actually to be understood and applied in practice.
For many, uncertainty arises in the transitions: between design and execution, between requirements and documentation – and between established practice and new expectations. This is where the risk of errors increases, and this is where up-to-date expertise becomes crucial," he points out.
This is new in NEK 400:2026
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PVC cables will be phased out in practice - from 1 July 2026, there will be a requirement that cables in electrical installations are at least halogen-free of class Dca. This is the most radical single change in NEK 400:2026 and affects virtually all new installations.
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New and expanded requirements for DC installations throughout the standard - photovoltaic systems, electric car charging, battery storage and ICT have been significantly updated, and the section for photovoltaic systems (NEK 400-7-712) has been completely revised.
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Ready-to-charge buildings and EV charging have been strengthened with separate sections for new forms of charging, including wireless charging and EV (V2G) feed-back.
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Two established solutions are discontinued: the so-called "Tjøme sleeve" (earthing electrode in sewer pipes) is removed from the standard, and surge protection in IT and TT systems must henceforth always be accident-proof - the previous alternatives with separate housing or current-controlled earth fault protection have been removed.
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Several sub-standards have been completely revised: swimming pools and water areas (702), temporary installations for exhibitions and events (711), photovoltaic systems (712), removable units (717) and power supply units for low voltage/batteries (751). In addition, the section for shelters (805) has been significantly strengthened - especially relevant with the current focus on emergency preparedness and civil protection.
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NEK 399 has also been revised in 2026. The most important change is that the tie-in cabinet (TKS) can now act as the installation's main distribution, allowing circuits to be established directly from there to external loads. The interior cabinet will then be underdistributed. This changes established practice for how installations are connected to the grid.
"It's the interpretation that decides"
Edgar Karlsen has extensive experience from the electrical industry and works as a consulting electrical engineer at Lofoten Tekniske. There he works with the design of electrical installations and coordination of technical systems, and has extensive experience with how the requirements of NEK 400 are applied in practice.
"Standards are often read as a definitive answer, but they must be understood correctly in order to work as intended," Karlsen points out.
On the course NEK 400:2026 – New and updated requirements in the regulations , he takes the participants through the changes with a clear focus on practice: What does this mean for the design? Where can misunderstandings arise in execution? And which areas should be checked extra carefully?
Update that reduces risk
Being up to date on NEK 400:2026 is not just about compliance, but about quality, safety and efficient implementation. Incorrect understanding can lead to rework, delays and increased risk – both technically and financially.
"It is almost always more expensive to correct mistakes afterwards than to do it right from the start," Karlsen emphasizes.
Karlsen points out that with an updated understanding, you are also more confident in the dialogue with customers, partners and control bodies.
Quotes for the NEK 400:2026 updates
NITO's course gives you a targeted and structured review of what is new in NEK 400:2026 and what it means in practice. The course is relevant for everyone who relates to NEK 400 on a daily basis, either in design, execution or supervision.
Edgar Karlsen
The course instructor, Edgar Karlsen, is an electrical installer and electrical engineer with broad experience from offshore projects in the petroleum sector, the electrical contracting industry and the role of professional responsible for the local Electrical Inspectorate (DLE) in Lofoten. He is a member of NEK's technical committee for NEK 400 (NK64) and thus has in-depth knowledge of the background, assessments and changes in the new version of the standard. As a course instructor, he is concerned with creating a safe learning environment, good academic discussions and ensuring that the participants are left with a solid and practical understanding of the regulations. Edgar is currently a partner and advisor at Lofoten Tekniske AS, and works with regulatory compliance and technical advice for customers in several sectors. He is also an examiner for the trade test in the electrician profession and the installer test.
