IEC 61439-1 & 2 Ed3 is out

So as many people who follow me will know that the IEC61439-1 and 2 Edition 3 has been released a while ago. In this article I would like to highlight some of the changes that has happened in this release.

We will start with IEC61439-1 for this article and do a follow up for IEC61439-2

IEC61439-1 gives information on test requirements that manufactures must comply to and cover basic safety. All Low Voltage Assemblies are required to be verified against these basic rules.

Edition 3 that was released in 2020 already has brought some extra challenges and updates to the 10 year old Edition 2 document. Some changes are minor while others are quite major.

• Better clarification on the condition of the test sample used for 10.3 Degree of protection of assemblies.
• Change in the structure of 10.2 Strength of materials and parts, this now includes the option to reference an excising tested design. the Mechanical operation now becomes a Sub clause under 10.2
• Minor clarifications on short circuit testing as defined under 10.11
• Introduction of Class1 and Class 2 Assemblies for protection against electrical shock as explained under 8.4.3, Under Class 1 all exposed -conductive parts shall be interconnected to the protective conductor. Class 2 has additional requirements for protective conductors that can no be isolated from the the main PE, for example an IT earth.
• Under Dielectric properties there are also a few clarifications and adjustments, Power frequency withstand voltage test now increases to 60 Seconds, there is new test procedures for for conductors covered by insulating materials that provide protection against electrical shock. There is also better clarification on the conditions required to exempt some auxiliary circuits.
• Further clarification for DC assemblies and PV requirements.
• Clarification that Electric convertor systems, Switch mode Power supplies, UPS's and adjustable speed power drive systems are tested to their own product standards but when incorporated into a Low-Voltage Assembly then this incorporation must be done in accordance to the IEC61439 series.
• New calculation methods under temperature rise calculations to slightly help reduce testing time , a new calculation to adjusted rated current for different ambient temperatures and a specific limit for temperature rise when using Aluminum conductors.
• The biggest single change is the introduction of group rated current (Ing) for circuits within a loaded assembly and the focusing of temperature-rise verifications on this. ( I will cover this clause 3.8.10.6 under a separate article as it is quite comprehensive)

Please follow me for the update on IEC61439 Part 2

References: IEC 61439-1, Intertek, Asta