This part of IEC 61643 is applicable to devices for surge protection against indirect and direct effects of lightning or other transient overvoltages. These devices are designed to be connected to the d.c. side of photovoltaic installations rated up to 1 500 V d.c. These devices contain at least one non-linear component and are intended to limit surge voltages and divert surge currents. Performance characteristics, safety requirements, standard methods for testing and ratings are established. SPDs complying with this standard are exclusively dedicated to be installed on the d.c. side of photovoltaic generators and the d.c. side of inverters. SPDs for PV systems with energy storage (e.g. batteries, capacitor banks) are not covered. SPDs with separate input and output terminal(s) that contain specific series impedance between these terminal(s) (so called two-port SPDs according to IEC 61643-11) are not covered. NOTE 1 In general SPDs for PV applications do not contain a specific series impedance between the input/output terminals due to power efficiency considerations. NOTE 2 Wherever reference is made to the electric power system or the power system within this document, this refers to the d.c. side of the photovoltaic installation.