DANSK DSF/PREN IEC 61857-41 PDF

This document describes a test procedure for the thermal evaluation of an electrical insulation system [EIS] for use in dry-type transformers operating at voltages of 1 kV and above. This Standard describes an evaluation procedure of an EIS to be used for coils constructed using the same EIS with insulation thickness being adjusted to maintain the Voltage Stress Level [VSL] at or below the tested values of the established EIS. When the transformer is constructed with multiple high voltage windings using different electrical insulation systems, each of these windings shall be evaluated using this procedure. The performance of any transformer designed and constructed using the EIS established in accordance with this document shall be evaluated in accordance with the application requirements set by the appropriate IEC Technical Committee.