Photovoltaic industry-proposed changes for the 1999 National Electrical Code for PV applications

An industry supported task group has written and submitted proposals for changes to bring Article 690 of the 1999 National Electrical Code (NEC) up to the state-of-the-art in photovoltaic (PV) device and system technology. This paper summarizes the proposed code changes, discusses background on both new and changed code text, and presents examples and analysis of three proposed changes. Topics such as the proposed new temperature compensation table for calculating maximum system voltage are analyzed. Requirements for calculating PV array currents used to size conductors using the proposed changes are presented. Impacts on PV installations, building integrated systems, and AC module installations are reviewed and coordination with other standards writing is discussed