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NC State Extension

Evaluating and Purchasing a Surge Protector

The electronic equipment in the offices should be plugged into surge protectors. The job of a surge protector is to shunt small momentary spikes in power away from the system plugged into it. These small momentary spikes can be caused by appliances like copiers, AC units, refrigerators, or then can come from the power grid feeding the building.
Surge protectors are not intended to stop a direct lighting strike. The surge protector will help with power fluctuate caused by the power being interrupted or restored due to a storm.

Not all surge protectors are created equal. There is a very wide range in the cord length, layout, size and abilities of surge protectors on the market. There are three ratings that should be present on a surge protector, Joules, Clamping Voltage, and Response Time. Below are the recommendations for a surge protector:

  • Joules: 1000 or greater
  • Clamping Voltage: 400 Volts or lower
  • Response Time: 10 Nanoseconds or less

Most surge protectors that will meet these specification will cost $25.00 or more. More information on surge protectors can be found at
There is a lot of equipment loss from electrical surges that are traveling through the network cables. These surges are caused by either nearby lightning strikes or excess power running in over a device that is on the network. Surge protection for network cables does exist.