Introduction to NEMA Arresters

Managing your surge protection assets is a critical task in the onerous responsibility of achieving a reliable power system. The purpose of this site is to assist users of surge arresters, in their arrester asset management decisions.

In the late 1970’s the surge protection industry experienced a significant paradigm shift in the surge protection of power systems. Since then, most surge protection decisions for power systems has involved Metal Oxide Varistor (MOV) technology.

There were several reasons for this shift in protection technology, but the primary reason was for better protection for the equipment on the lines. This improved protection from lightning and switching surges have led to more reliable power systems throughout the world.

However, porcelain housed Silicon Carbide (SiC) arrester technology can still be found on power systems today in spite of the fact that they are subjecting the systems with a higher risk of outages due to lightning that can be achieved with MOV technology. The decision to remove these old arresters is difficult so this site was created to help make those decisions easier and understandable.

This site will show you:

  • how to quickly determine where your system is at higher risk due to the use of the last generation SiC technology
  • the best course of action to replace those assets
  • how to select the replacement protection
  • installation options
  • how to improve system reliability

Useful Info

Make old arrester replacement a part of your preventative maintenance schedule in order to improve systems.