Woodworth on Arresters

Improving TOV Testing

August 26, 2017 • ARTICLE ARCHIVE, Woodworth on ArrestersComments Off on Improving TOV Testing

Members of my taskforce in IEC TC37 MT4 are working to rationalize type tests within IEC 60099-4. In the process, we have been looking at a test that has been basic for all IEC type arresters since the 1991 edition, namely the Temporary Overvoltage Test (TOV) – also known as the ‘Power-frequency voltage-versus-time test’. Questions ...

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Importance of Line Entrance Arresters

July 1, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

At most air-insulated substations, the arrester mounted at the transformer is close enough to other equipment to provide effective protection from flashover. However this applies only if the breakers are closed. If a breaker is open, the insulators on its...

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When to Remove an Arrester from Service

June 24, 2017 • Arresters, ARTICLE ARCHIVE, Editorial Columns, Woodworth on Arresters

Over the years, I have been asked this many times. The reply is not always straightforward since a number of competing considerations need to be taken into account. Here, I would like to share the logic and rationale used to formulate an answer in each case:...

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Energy Ratings of Distribution Arresters

June 10, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

“What is the kJ/kV Uc rating of a Class 1, 10 kA arrester? This type of question has often been asked when it comes to distribution arresters. Yet finding an answer has not been easy since these arresters (formerly referred to as Class 1) never had energy...

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Lightning Performance of Distribution Lines

May 20, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

The most recent edition of IEEE Technical Guide 1410 on how to improve lightning performance of distribution lines was issued in 2010 when many improvements were added. Because the experts involved had deep roots in the world of lightning and system transient...

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Thermal Imaging of Arresters

May 13, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

It is a challenge to accurately describe what arresters will be like 35 years from now. But some things can be predicted with near certainty. One is that they will be smart arresters. In fact, the smart arrester is just around the corner and its ‘brain’...

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IEC Standards for Arresters: Now & In the Future

May 13, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

Harmonization As a long-time member and contributor to both IEC and IEEE, I feel that there is now excellent collaboration among those involved in setting standards for surge arresters. Sill, while both IEC and IEEE arrester Working Groups have been trying to...

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Do Your Station Class Arresters Have Adequate Fault Current Withstand Capability?

November 26, 2016 • ARTICLE ARCHIVE, Woodworth on Arresters

Station class arresters since 1980 have typically been based around various types of metal oxide varistors. Despite having been designed to withstand most power system surges, it’s still possible for these varistors to become overloaded or fail such that...

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