This document provides recommended best practices for photovoltaic system (PV) operations and maintenance. This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www. National Renewable Energy Laboratory, Sandia National Laboratory, SunSpec Alliance, and the SunShot National Laboratory Multiyear Partnership (SuNLaMP) PV O&M Best Practices. assessed, and controlled or eliminated. This guide may not include all operations and maintenance routines or scenarios, but provides general guidance for safety practices, management, operations, and preventative maintenance of PV. Electric shock hazards from high DC voltages require comprehensive arc-flash protection, properly rated personal protective equipment (PPE), and strict lockout-tagout procedures during installation and maintenance. The PV array supplies DC voltage to an inverter, which converts the DC into AC. Some installations have batteries, automatic transfer switching units, monitoring and metering equipment, and.