Woodworth on Arresters

PPC Insulators

Importance of Line Entrance 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... Read More

Understanding Energy Rating of Distribution 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 was never easy since these arresters (formerly referred to as Class 1) never had energy... Read More

Fault Current Withstand Capability of Station Class Arresters

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

Thermal Imaging of 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’... Read More

Lightning Performance of Distribution Lines

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... Read More

Helping Understand the VI Characteristic Curve

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... Read More

Transmission Line Arresters Lower Losses & Increase Reliability

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... Read More