ZeroSurge filters out surge damage

Most surge protection devices suppress power surges, but they don't eliminate them. Rudy Harford, chief engineer at ZeroSurge, said the company wants to correct that.

In 1989, Harford designed a surge protection circuit that was based on a filter, rather than a surge suppressor, which is what most surge protection devices use.

About four or five years ago, when a military supplier asked if ZeroSurge could extend the product's voltage operating range, the company said yes. 'We want to eliminate the surge altogether,' Harford said.

Harford and his team added a cancelling winding voltage feature that he said completely eliminates surge damage.

Surges can be as large as 6,000 volts on a power line, he said. Metal oxide varistors will start clamping up at a couple of hundred volts. The ZeroSurge filter acts on surges independent of the voltage, he said. The filtering action is continuous.

To understand the ZeroSurge product, visualize a screen with one-inch squares, Harford said. It will let little stuff come through, but it will stop the bigger stuff. Higher frequencies and surges won't get through.

Potential users include anyone who has a critical application and is concerned about the safety of their equipment, such as medical workers or the military, Harford said.

Prices start at $130 and go up from there. The company offers a 10-year warranty, Harford said.

More information:

And check out the GCN Lab's review of ZeroSurge's surge protector here.

About the Author

Trudy Walsh is a senior writer for GCN.


  • Records management: Look beyond the NARA mandates

    Pandemic tests electronic records management

    Between the rush enable more virtual collaboration, stalled digitization of archived records and managing records that reside in datasets, records management executives are sorting through new challenges.

  • boy learning at home (Travelpixs/

    Tucson’s community wireless bridges the digital divide

    The city built cell sites at government-owned facilities such as fire departments and libraries that were already connected to Tucson’s existing fiber backbone.

Stay Connected