Overview

James M. Bannon

Chief Electrical Engineer
STV Incorporated
Douglassville, Pennsylvania

Design of the electrical installations in a building used to be simple and straightforward. Such installations generally included electrical service from a utility company; power distribution within the building for receptacles, air conditioning, and other electrical loads; lighting; and a few specialty systems, such as fire alarm and telephone. There were, of course, some specialized installations for which this simple description did not apply, but such buildings were uncommon. Now, however, design of electrical systems has become more complex and sophisticated.

This development has been driven by rapid advances in technology, availability of computers and computerized equipment, more enlightened life-safety and security concerns, and changes in the philosophical outlook of workers toward their workplace and their need for a comfortable environment. To meet these needs, a new building will likely include in its electrical installation an access control system, intrusion detection system, an extensive computer data network, Internet access, uninterruptible power supply, and numerous other systems not commonly installed in the past. Corollary to the advent of these new building systems is the need for suitable power quality to support them. Though highly sophisticated and capable, these systems can easily be disrupted or damaged by power system anomalies such as sags, surges, noise, and power outages. Electrical design elements to protect against these disturbances must be included and must be designed to be appropriately sensitive, fast, and robust. The introduction of electrical competition in some states adds further...