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A power supply update on the transition of IEC 62368-1 Edition 2 to Editions 3 and 4

Monday, October 17, 2022

I thought it was a good time to provide an update on IEC 62368-1 now that the 3rd edition is gaining traction in the power supply industry. Certainly, questions are being posed about the 4th edition.

Like other IEC standards, IEC 62368-1 is written by a Technical Committee, in this case TC 108. Regions or countries, UL, CSA, EN, then may (or may not) adopt the standard or may apply minor deviations.

In March 2015, I mentioned that a Hazard-Based Safety Engineering (HBSE) IEC 62368-1 standard will be replacing IEC 60950-1 and IEC 60065, covering hazards and hazard prevention for ITE (Information Technology Equipment) and audio / visual equipment. In June 2018 I went into that in a little more detail.

Reviewing the editions:

First was edition 1: IEC 62368-1:2010 1st edition and UL/CSA 62368-1:2012.

Many power supply companies opted to wait until the 2nd edition was announced before transitioning from IEC 60950-1.

Next came edition 2: IEC 62368-1:2014 2nd edition, EN 62368-1:2014, UL/CSA 62368-1:2014.

The power supply industry transitioned to the 2nd edition ahead of EN 60950-1 being withdrawn on December 20th, 2020. IEC 62368-1 included the latest hazard-based safety principles.

The newest edition is 3: IEC 62368-1:2018 3rd edition, EN 62368-1:2020 + A11:2020 and UL/CSA62368-1:2019.

Edition 3 cannot be used for presumption of conformity (per the Low Voltage Directive) as it is not listed in the EU Official Journal. A self-declaration, backed by suitable technical documents, can be used based on edition 3 reports.

On the other hand, UL/CSA is planning to transition to the 3rd edition on Jan 6th, 2023. This will be mandatory for new products placed on the market after that date and be applicable for existing products if significant changes are needed to the product safety file. As UL does not withdraw standards, existing products can continue to apply the UL/CSA mark for the 2nd edition if required.

These updated CB 3rd edition reports will be more appropriate for South America, Korea, Taiwan and China, as they have not adopted the 2nd edition.

There is no withdrawal date planned for the 3rd edition.

IEC 62368-1 edition 4 may be published in the first quarter of 2023.

It is highly anticipated that this version will be approved in the Official Journal for Europe, (skipping the 3rd edition) allowing it to be used for Declarations of Conformity for the CE mark.

It is unknown if countries that jumped directly to edition 3 will transition to edition 4. Sources indicate that China is not planning to adopt 4th edition.

What is TDK-Lambda doing?

Newer products are being certified to the 3rd edition of IEC 62368-1, while maintaining the 2nd edition. This allows continued compliance for the European CE, covering the UKCA marks and providing CB certification for countries that did not adopt the 2nd edition. It is intended that 2nd and 3rd edition reports will be maintained until the 4th edition is added to the EU Official Journal. Both 3rd and 4th editions will probably be maintained to support countries that are not adopting the 4th edition.

One example is one of TDK-Lambda’s recently launched products - the CN-B110 wide range DC-DC converter for rail and industrial applications - having both edition 2 and 3 certifications.


CN300B110-12 DC-DC converter

Looking at history, there may well be changes in dates and so it would be wise to keep in communication with your local safety officials. Certainly ensure your Engineering budget anticipates addition certification charges.

Power Guy