NDUSTRIAL AND COMMERCIAL ELECTRICITY CONSUMERS

are increasingly impacted by poor power quality and reliability (PQ&R). A utility distribution system fault, even hundreds of miles away, can cause widespread voltage sags that shut down susceptible process equipment [1]. Correlating process interruptions with voltage disturbances requires prompt notification of such PQ&R events. Effective communication with the utility company and assessment of mitigation equipment options are greatly facilitated when local historical PQ&R data are available, but only if the information is put in a form that the customer can act on. A Web-based, near real-time PQ&R monitoring system is continuing to be put in place to provide such information, both locally and on a nationwide basis [2]. Low-cost monitors record PQ&R event char-acteristics and, using an internal modem, transmit event data via the Internet to a central database. The database servers are a component of the system, and no additional hardware or software is needed by the end user. The monitor system infrastructure, shared by all monitor owners, provides capa-bilities for data aggregation and display, e-mail and pager notification, site administration, and summary reporting of the data using a Web browser. The system provides real-time notification of PQ&R events at single or multiple facilities and access to statistical informa-tion and trends related to PQ&R events as well as voltage regulation and imbalance. A principal goal is deployment of a vast network of moni-tors, which cannot be accomplished unless the monitors are affordable and the infra-structure is scalable. IE