The End-Use Load and Consumer Assessment Program (ELCAP) being conducted for a regional utility has more than 20, 000 sensors installed in 550 buildings located in Washington, Oregon, Idaho, and Montana. Maintaining perfect data capture rates from these installations is an impossible task. Even extremely high rates of reliability result in significant numbers of failures every week. Procedures to handle the flow of problems and corrective actions have been developed and implemented at a laboratory during the past four years.

In this paper, the process used to maintain adequate performance from the field.installed sensors and data collection equipment will be documented. Some of the more significant problems and solutions that have been developed will be explained. The establishment of maintenance queues, assignment of priorities, and development of reliable field procedures will be presented. Several components of the procedures developed at the laboratory are critical to maintaining reliable operation of the network of instrumented sites. The way in which these project elements interact to result in identification of the problem sites will be explored. The key objective of this paper is to discuss how a limited staff copes with maintaining adequate operational performance from the data collection system installed in the field.