AS 61869.14:2021 Instrument transformers Part 14: Additional requirements for current transformers for DC applications (IEC 61869-14:2018 (ED 1.0) MOD). Sequence of type tests
The sequence of tests is not specified and may be agreed between the purchaser and the supplier.
Before starting the type test sequence, the following routine tests shall be performed:
• power-frequency voltage withstand test on primary terminals;
• partial discharge measurement.
NOTE The partial discharge measurement is generally performed together with the power-frequency voltage withstand test.
After the type test sequence, the current transformer shall be subjected to all routine tests detailed in 7.3.
The DC applied voltage test may be performed before the polarity reversal test. In this case, it does not need to be repeated after the type test sequence. Sequence of routine tests
The sequence of tests is not specified, but the accuracy tests shall be performed after the dielectric tests.
7.2 Type tests
7.2.2 Temperature rise test
Subclause 7.2.2 of IEC 61869-6:2016 is applicable with the addition of, and Duration of test
Subclause of IEC 61869-2:2012 is applicable. 402 Temperature and temperature rise
The purpose of the test is to determine the average temperature rise of the primary conductor, the secondary windings (if present), the primary and secondary converters and, for oilimmersed transformers, the temperature rise of the top oil, in steady-state conditions when the losses resulting from the specified service conditions are generated in the current transformer.
The average temperature of the secondary windings (if present) shall be determined by the resistance variation method.
Thermometers or thermocouples shall measure the temperature rise of parts other than the windings. The top-oil temperature shall be measured by sensors applied to the top of the metallic head directly in contact with the oil. The temperature rise shall be determined by the difference with respect to the ambient temperature. Test modalities
The current transformer shall be mounted in a manner representative of the mounting in service.
The current to be applied is the rated continuous thermal current. The test shall be continued until the steady-state temperature of the transformer has been reached in accordance with 61869.14 pdf download.