IEC 61869-14-2018 pdf free.Instrument transformers – Part 14: Additional requirements for current transformers for DC applications. lmmunity test
Subclause of lEC 61869-6:2016 is applicable in the case of electronic DCCTs.
7.2.6Test for accuracy
Test circuits are given in Annex 6D of lEC 61869-6:2016 for analogue outputs and Annex 9Dof IEC 61869-9:2016 for digital outputs.
To prove compliance with the specified accuracy class, the test shall be carried out at eachvalue of current given in Table 1403,at rated burden,and at ambient temperature,unlessotherwise specified.
For measuring current transformers,the test shall be made up to the rated primary current(pr).
For primary current equal to zero, the measured absolute error shall not exceed the value ofthe absolute error allowed at 0,05 x Ipr.
For the test at accuracy limit primary current, the DC current source might not be available.The accuracy of the whole system may be tested using an alternative signal input method.The supplier shall supply all necessary information for the calculation of the accuracy at thespecified primary input level.
For some technologies (e.g zero-flux CTs),instead of applying the primary current on theprimary terminals,an auxiliary test winding may be used to supply a corresponding testcurrent. DC current measurement
For analogue output with rated delay time, it is not necessary to insert a delay time devicebetween the reference transformer and the accuracy measurement system. current measurement
Accuracy tests shall be performed in accordance with 7.2.6 of IEC 61869-2:2012. Tests for accuracy of current transformers with digital outputs
Subclause 7.2.6 of IEC 61869-9:2016 is applicable with replacement of the two lastparagraphs by the following ones:
Accuracy tests shall be performed over a minimum period, during which severalmeasurements shall be averaged. The details of the test arrangement and timing and/orbandwidth of the test system shall be provided in the accuracy test report.
The measurement period needs to be sufficient to secure the accuracy measurementconsidering ripple oscillations and the effect of the sampling.Time should be less than 10 s.7.2.1401 Polarity reversal test with partial discharge measurement
This test is applicable to DcCTs having Um equal to or above 100 kV.IEC 61869-14 pdf download.