Arc flash calculations for a 1.3MW photovoltaic system

When planning for the installation of a 1.3MW photovoltaic system, and its integration into an existing facility's electrical system, an arc flash study was performed to determine the best protective device settings to minimize the arc flash energy in the photovoltaic system, and to determine the effect of the additional short circuit current on the existing system arc flash calculations. The existing system has distribution at 13.8kV and two 10MVA transformers to a 2.4kV feeder system. The photovoltaic system adds the hazard of 500 VDC sub-array collection wiring and terminations. The DC arc flash exposure of PV systems, including those in the inverter enclosures, can be complicated, and this paper outlines the basic data collected for the study, the steps taken to complete the calculations, the methodology used, the results, and the team's learnings.