Surge Protective Devices (SPDs) provide the best protection from both externally and internally generated surges when located as close to the building distribution system as possible. For cost and space reasons many buildings only include one SPD located at the main incoming load center and do not cascade SPDs throughout the building as recommended by IEEE. Siemens QSPD series of SPDs are economical and easy to install in most panels throughout a building so that whole facility protection can be obtained.