Woodworth on Arresters

Lightning Performance of Distribution Lines

January 20, 2018 • Arresters, ARTICLE ARCHIVE, Woodworth on ArrestersComments (0)

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 modeling, 1410 contains equations and estimates not usually found in similar IEEE or ...

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Helping Understand the VI Characteristic Curve

January 13, 2018 • ARTICLE ARCHIVE, Editorial Columns, Woodworth on Arresters

The voltage-current (VI) characteristic of its varistor is without doubt one of the most important parameters of any surge arrester. Still, most arrester users do not see this characteristic represented in graphical form but rather only as tables of discharge...

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Transmission Line Arresters Lower Losses & Increase Reliability

January 2, 2018 • Article of the week, Utility Practice & Experience, Woodworth on Arresters

Given the possible application of line arresters to mitigate the effects of lightning, it strikes me as inexplicable that arresters are not being used more often to reduce momentary lightninginduced outages on transmission lines. I have asked experts to...

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What’s Next After Succession of Different Arrester ‘Eras’?

November 25, 2017 • Arresters, ARTICLE ARCHIVE, Woodworth on Arresters

Like many other things, the surge arrester was born of necessity. But while most might guess that arresters were introduced around the late 1800s when power lines first entered operation, they actually appeared 50 years earlier. Their initial function, in...

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Improving TOV Testing

August 26, 2017 • ARTICLE ARCHIVE, Testing, Woodworth on Arresters

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)...

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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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