Damaging surge currents and transient voltages originate from both inside and outside of facilities. External surges and transients are caused by utility load switching, lightning and man-made and natural accidents. Internal surges and transients are caused by heavy inductive load switching (e.g., HVAC equipment, elevators, etc.), switching of power factor correction capacitors and other switching loads like photo copiers and/or laser printers. Cascading of surge protective devices (SPDs) in a facility provides the ultimate in transient surge protection. The application of an SPD at the service entrance, sub-panels, and on sensitive equipment receives benefits of cascading suppressors. By cascading SPDs, damaging surges are reduced down to safe levels via a step-by-step approach. EFI offers a complete facility-wide cascading solution to protect the whole facility from both externally and internally generated transients. Recommended products for service entrance applications;Titan SE. Recommended products for branch panel applications include the Titan BP, Titan MBP and OSW.