DIN EN 60076-14:2014-08

This part of IEC 60076 standardizes liquid-immersed transformers that use high-temperature insulation. As a system, the solid insulation may encompass a broad range of materials with varying degrees of thermal capability. The insulating and cooling liquids also vary substantially, ranging from mineral oil to a number of liquids that also have a range of thermal capability. This standard builds on the information and guidelines documented in other parts of the IEC 60076 series. Accordingly, this standard follows two guiding principles. The first principle is that liquid-immersed transformers are well known and are well defined in other parts of this series and therefore, the details of these transformers do not need to be repeated in this standard. The second principle is that the materials used in normal liquid-immersed transformers, typically kraft paper, pressboard, wood, mineral oil, paint and varnish, which operate within temperature limits, are well known and are considered normal or conventional. All other insulation materials, either solid or liquid that have a thermal capability higher than the materials used in this well-known system of insulation materials are considered high-temperature. Consequently, this standard or "normal" insulation system is defined as the "conventional" insulation system for comparison purposes and these normal thermal limits are presented for reference to illustrate the differences between other higher temperature systems. This standard addresses loading, overloading, testing and accessories in the same manner. Only selected information for the conventional transformers is included for comparison purposes or for emphasis. All other references are directed to the appropriate IEC document for which either a high-temperature insulation or a combinations of high-temperature and conventional insulation is used and which operate at temperatures above conventional limits. The standard is applicable to: - power transformers in accordance with IEC 60076-1; - convertor transformers according to IEC 61378 series; - transformers for wind turbine applications in accordance with IEC 60076-16; - arc furnace transformers. The responsible committee is DKE/K 321 "Transformatoren" ("Transformers") of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.