Provides an overview of the different kinds of surge overvoltages that can occur on low-voltage installations and equipment. In particular: - the magnitude and duration of typical surges as well as their frequency of occurrence; - information on overvoltages resulting from interaction between power and communication systems; - guidelines when considering interface issues in relation to insulation coordination; - guidelines concerning surge protection means on the basis of availability and risk considerations, including interaction within the system; - highlights temporary overvoltages and other factors that have to be taken into account for insulation coordination, primarily related to protective control using surge protective devices.