IEC 61850-3:2013 defines the general requirements, mainly regarding construction, design and environmental conditions for utility communication and automation IEDs (intelligent electronic devices) and systems in power plant and substation environments. These general requirements are in line with requirements for IEDs used in similar environments, for example measuring relays and protection equipment. This new edition includes the following significant technical changes with respect to the previous edition: – requirements are in line with those of other equipment used in the same environment (e.g. protection relays); – product safety added based on IEC 60255-27; – EMC requirements completed and in line with IEC 60255 series and IEC 61000-6-5.