The first point:

         When testing the transformer A phase, the tester IA is connected to protect the A phase of the high voltage side, the tester IB is connected to protect the B phase of the low voltage side, and the IC on the tester end is connected to the C phase of the low voltage side. We need to calculate the converted current on the high voltage side. The formula is: I'A=(IA-IB)/1.732, I'B=(IB-IC)/1.732, I'C=(IC-IA)/1.732;

 

         Second point:

         If the high-voltage side A phase current, B or C does not conduct current, the converted current is: I'A=(IA-IB)/1.732=(IA-0)/1.732=IA/1.732; 　 I'B=(IB- IC)/1.732=(0-0)/1.732=0; 　 I'C=(IC-IA)/1.732=(0-IA)/1.732=-IA/1.732;

 

         The third point:

         If only the current is applied to the B terminal of the test transformer, and no current is applied to the A or C terminal, the converted high-voltage side three-phase current is: I'A=(IA-IB)/1.732=(0-IB)/1.732=-IB /1.732; 　　I'B=(IB-IC)/1.732=(IB-0)/1.732=IB/1.732; 　　I'C=(IC-IA)/1.732=(0-0)/1.732=0.

 

        The above is how to wire the relay protection tester. If you want to use the relay protection tester and its model, you can pay attention to us. The editor will introduce the use and application scenarios of the instrument in a future article. Thank you.