Instrument transformers - additional requirements for current transformers.
The standard applies to newly manufactured inductive current transformers for use with measuring instruments and protective devices, with rated frequency of 15–100 Hz. It supplements the general requirements of IEC 61869-1 with additional requirements for current transformers, including transient-performance requirements (formerly IEC 60044-6).
Electronic and low-power instrument transformers are covered by other parts of the series (61869-6 and subsequent parts).
The accuracy class and rated burden of a transformer according to IEC 61869-2 determine the error of the current-measurement chain in a substation or depot switchboard - selecting the transformer and meter to compatible classes closes the uncertainty budget.
