Lightning Arrester

A device on an electric power or telecommunication system which diverts power to ground when the system takes sees an extreme voltage spike. These devices are designed to work with a direct lightning strike, or an extreme surge from an fault somewhere down the line. The lightning arrester is essentially an automatic switch designed to work instantaneously.

Surge Arresters (SPDs)

When lightning strikes close to a powerline it induces a surge in the lines due to the electromagnetic pulse (EMP). EMPs are also called “transient electromagnetic disturbances”. Surge arresters are designed to prevent surges caused by a “lightning flash” EMP or other transients from affecting large areas of the grid.  They do not protect against a direct strike on your line, this device stops surges which have a slower rise than direct strikes, which have a rapid rise in voltage. Electromagnetic Compatibility Engineers specialize in understanding the phenomena and damage caused by EMPs.