Routine Assay

The tests of the current transformers must be made according to the standard NBR 6821 – Current transformer – Test method. The tests to be carried out on the transformers are as follows:

– Routine Tests: These tests confer the quality and uniformity of the workmanship and materials used in the manufacture of current transformers. The routine tests required by NBR 6856/81:                  111949

– Accuracy;

– Induced voltage;

– Partial discharges;

– Insulation and capacitance power factor;

– Polarity;

– Industrial frequency withstand voltage;

– Mechanical resistance to internal pressure.

– Type Tests: Type tests are made to show whether a particular type or type of transformer is capable of working satisfactorily under the specified conditions:

– Temperature elevation;

– All the tests explained above;

– Winding resistance;

– Atmospheric impulse withstand voltage;

– Maneuver impulse withstand voltage;

– Rated thermal current;

– Radio interference (Vn 145kV);

– Hot sealing.

– Summary Specification: The specification of a current transformer causes prior knowledge of the use of this equipment for measuring or protection service.