IEC 60728-11:2010(E) deals with the safety requirements applicable to fixed sited systems and equipment. As far as applicable, it is also valid for mobile and temporarily installed systems, for example, caravans. Additional requirements may be applied. It is intended to provide specifically for the safety of the system, personnel working on it, subscribers and subscriber equipment. It deals only with safety aspects and is not intended to define a standard for the protection of the equipment used in the system. This third edition cancels and replaces the second edition published in 2005. This edition constitutes a technical revision and includes the following significant technical changes with respect to the previous edition: The list of "differences in some countries" was transferred from the "Foreword" to informative Annex D. Some new terms and definitions were added. All Figures were reworked among other things concerning equipotential bonding and earthing details and were incorporated in the text at the appropriate places. Clause 11 "Protection against atmospheric overvoltages and elimination of potential differences" was completely reworked and re-structured taking into account among other things the provisions and requirements of the IEC 62305 series on "Lightning protection". New informative Annex A on "Earth loop impedance" was added. New informative Annex C on "Examples of calculation of risk due to lightning" was added. Former Annex B on "Special conditions using IT power line networks" was re-worded and incorporated in Annex D as "Difference in Norway".