Over 80% of transient surges are caused by internal sources such as load switching and normal equipment operations. The installation of ABB OVR UL 1449 3rd edition pluggable AC DIN rail SPDs will combat these surges and provide protection to valuable equipment and help keep an operation up and running. This new product range is approved as type 4 recognized components and is usable in type 2 applications. These products are of the same high quality as ABB UL 1449 2nd Edition devices, with improved safety as a result of additional testing required by the UL 1449 3rd edition standard. Installation at branch panels, control panels and terminal equipment is recommended to provide the most complete protection.