Setting the earth fault compensation factor by secondary injection

The EuroProt+ distance protection function block is using earth fault compensation factors for accurate impedance calculation in case of phase to ground faults. The formula of the factors is as follows:

(R0-R1)/3R1 for the resistance and

(X0-X1)/3X1 for the reactance

Performing secondary injection to test the distance protection requires proper settings in the test equipment as well. When using Omicron or ISA relay testers, please use the RE/RL and XE/XL mode for earth fault compensation factor definition. These will correspond to the above formulas:

RE/RL=(R0-R1)/3R1

XE/XL=(X0-X1)/3X1

If the compensation factor in the tester shall be given in a different format, please use the attached example for the conversion.