13.4 Impedance protection SEMOD53525-1 v213.4.1 Full scheme distance protection, mho characteristic ZMHPDIS(21) M14944-3 v10Prepare the IED for verification of settings outlined in Section "Preparing the IED toverify settings".Keep the current constant when measuring operating characteristics. Keep the currentas close as possible to its rated value or lower. But make sure it is higher than the setminimum operating current.Ensure that the maximum continuous current in an IED does not exceed four times itsrated value, if the measurement of the operating characteristics runs under constantvoltage conditions.To verify the mho characteristic, at least two points should be tested.In the following, three test points are proposed. The mho characteristic always goesthrough the origin, which automatically gives a fourth point for the characteristic.13.4.2 High speed distance protection zones, quadrilateral and mhocharacteristic ZMFPDIS (21) GUID-DF1650F4-EC3E-402B-BE26-EF2EF1034237 v6Prepare the IED for verification of settings outlined in section "Requirements" andsection "Preparing for test" in this chapter.Measure operating characteristics during constant current conditions. Keep themeasured current as close as possible to its rated value or lower. But make sure it ishigher than the set minimum operating current.Ensure that the maximum continuous current to the IED does not exceed four times itsrated value, if the measurement of the operating characteristics runs under constantvoltage conditions.The test procedure has to take into consideration that the shaped load encroachmentcharacteristic is active. It is therefore necessary to check the setting. To verify thesettings with the shaped load encroachment characteristic the test should be carried outaccording to figures 42 and 43 and tables 19 and 20. In cases where the loadencroachment characteristic is activated tests according to the adjusted figures shouldbe carried out.To verify the settings for the operating points according to the following fault typesshould be tested:Section 13 1MRK 502 073-UUS ATesting functionality by secondary injection146 Generator protection REG670 2.2 ANSI and Injection equipment REX060, REX061, REX062Commissioning manual
