Rationalizing the testing process

A key document on rationales for the testing of surge arresters could have wider implications for testing standards across the IEC.

How to test surge arresters (photo:ikar.us)

Surge arresters are indispensable devices employed in the transmission and distribution of electricity. They are used to protect electrical equipment from over-voltage transients caused by external events such as lightning or internal switching. IEC Technical Committee 37 prepares standards for that essential part of an electricity network. It focuses on several areas, one of them being test standards for the equipment. The IEC 60099 standards are widely used across the electricity transmission and distribution industry and specify several performance and safety tests for a variety of different surge arresters.

New ground-breaking document in the works

The group, responsible for maintaining the test standards for high-voltage metal oxide surge arrester standards, is working on the publication of a ground-breaking document, named “Type Test Rationales” , which aims to rationalize the testing process and make it more economical for both manufacturers and users.

“We are looking into the possibility of releasing the test rationales as an IEC Technical Report. We have completed around 50% of the work that would go into such a document. The alternative would be to include the work in the new edition of IEC 60099-4, which would take more time,” says Jonathan Woodworth, Co-Convenor of the group.

The idea behind the report is to examine all the existing tests and weed out the unnecessary ones, some of which have become obsolete over time, by way of a formal procedure. This should enable companies and users to save a considerable amount of time and money. More than that, according to IEC expert Frédérick Dubé, who has been working on the new document, “if you know exactly why you do a test and why you do it according to a specific procedure, it helps you to interpret the test results, enabling users to accept certain deviations from the specifications. It also allows the industry to project itself in the long-term. If some tests need to be modified in the future, or a new family of products needs to be tested, it is much easier to integrate them into existing standards using a document which sets test rationales".

The test rationales would include a sample selection rationale, a test procedure rationale, explaining why the procedure is relevant to the test, and an evaluation rationale. This third section would be required to clarify why the test is evaluated in such a manner and why it is important to the product in its real-life application. Each test rationale also includes useful additional information such as historical notes explaining the evolution of this test over time in past revisions of the standards.

A wider impact

Standards for testing are part of the IEC DNA. They are at the core of the work of many IEC TCs. All electrical and electronic equipment needs to be tested, so it can be used reliably and safely, whether in industry or by consumers. And these tests need to be performed in a standardized way.

According to Frédérick Dubé, the document on test rationales has the potential to become a widely used reference tool inside the IEC. “In my opinion, these rationales could be used for almost every IEC test Standard. They could either be directly added to some short standard documents or referred to for other test publications. Such a document is also very enriching in that it helps to transfer expertise from more experienced members to new members of the IEC".

Much effort was put into aligning with the US-based Institute of Electrical and Electronics Engineers (IEEE) publications on surge arresters.  “For many years now, we have worked to harmonize IEC Standards with IEEE ones so that vendors can sell their products all around the world and don’t have to fulfil different requirements if they want to export to or import their products from the US,” Woodworth explains.

Dubé adds that “it is also useful to users who would like to buy both IEEE or IEC qualified products”.

Feedback from the IEC community welcome!

Jonathan Woodworth has himself been actively involved both in the IEC and the IEEE for many years. “Other younger experts like Frédérick are taking up the torch and doing brilliant work. We would need to recruit more experts from the user community, however,” he adds.

Both are very keen to explain the work they are doing on test rationales and would be able to share a presentation with those interested. You can contact Jonathan Woodworth at : jwoodworth@arresterworks.com or Frédérick Dubé at dube.frederick@hydroquebec.com