Tech Talk: How do surge suppressors protect circuits from harmful voltages?

Q:   How do surge suppressors protect circuits from harmful voltages?

A:   The short answer is that they shunt (“short out”) the high voltage to ground.

Each surge suppressor is connected to a specific circuit. It switches the connected power—or communication circuit—to earth ground much like an automatic “Off/On” switch. Or if the surge device is a fuse, it opens the connection, thus protecting the main device. The trick is to clamp at a voltage high enough for the control circuit to operate normally while dissipating highly damaging voltage to ground. This is called the “clamp level voltage” of the surge protector.

Certain high voltages happen very fast—sometimes as fast as microseconds (µ sec). Lightning is a perfect example. The table below shows many of the devices Kele offers. It also describes the “clamp level voltage” and speed of each protecting technology component built within the suppressor. Notice that many suppressors have multiple stages of components to better protect the circuits connected.

Learn more by reading, “The Protection Zone,” an insightful article describes how to place needed suppressors for equipment protection.

Click here to download a copy of the table below.


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