This standard deals with the maintenance of grid-connected photovoltaic installations. It provides guidance for maintenance, inspection, repair, testing, documentation and spare parts inventory. In particular, the aspects of safety, economy and protection of the investment by effective and efficient maintenance are included. In addition to the PV generator, all other system components up to the mains connection are also taken into account over their estimated service life. As PV systems can have power ratings from a few kWp up to several MWp, the recommendations may not fit for all plants equally accurate. The standard is aimed primarily at owners and operators of commercial PV systems. It specifies which maintenance measures should be implemented comprehensively, safely, economically and effectively in conjunction with an individually tailored maintenance concept.