A good ground is important for surge protection devices (SPD) to work properly. AC power SPD’s are designed to divert surge current to ground by providing the least resistive path. Without surge protection on the AC power, the surge current will look for other paths to a good ground. In many cases this path is found through electric/electronic equipment. Once the dielectric strength of the components in electronic equipment has been surpassed large currents begin to flow through the sensitive electronics thus causing failure.
