The Institute for Standardization of Bosnia and Herzegovina, through its Technical Committee BAS/TC 8, Insulation coordination, high-voltage testing, and instrument transformers, has adopted the second edition of BAS EN 61869-4:2025, Instrument transformers – Part 4: Additional requirements for combined transformers, by translation method. This edition is a translation of the English version of the European standard EN 61869-4:2014.

BAS EN 61869-4:2025, which is part of the IEC 61869 series, applies to newly manufactured combined transformers for use with electrical measuring instruments and electrical protective devices at frequencies from 15 Hz to 100 Hz.

The requirements and tests of this standard, in addition to those in IEC 61869-1, IEC 61869-2, and IEC 61869-3, cover current and inductive voltage transformers that are necessary for combined instrument transformers.

The original texts of the standard were prepared by the International Technical Committee IEC/TC 38, Instrument Transformers.