The parameters for the four step residual overcurrent protection are set via the localHMI or PCM600. The following settings can be done for the function.Common base IED values for the primary current (IBase), primary voltage (UBase)and primary power (SBase) are set in global base values for settings functionGBASVAL.GlobalBaseSel: Selects the global base value group used by the function to defineIBase, UBase and SBase as applicable.SeqTypeUPol: This is used to select the type of voltage polarising quantity i.e. Zeroseq or Neg seq for direction detection.SeqTypeIPol: This is used to select the type of current polarising quantity i.e. Zeroseq or Neg seq for direction detection.SeqTypeIDir: This is used to select the type of operating current quantity i.e. Zeroseq or Neg seq for direction detection.8.4.3.1 Common settings for all steps M15282-81 v10AngleRCA: Relay characteristic angle given in degree. This angle is defined asshown in Figure 81. The angle is defined positive when the residual current lagsthe reference voltage (Upol = 3U0 or U2)Upol = -3U0 orIN>DirRCAOperation-3U2IEC05000135-5-en.vsdxIEC05000135 V5 EN-USFigure 81: Relay characteristic angle given in degreeIn a normal transmission network a normal value of RCA is about 65°. The settingrange is -180° to +180°.1MRK 505 393-UEN B Section 8Current protectionLine differential protection RED650 2.2 IEC 169Application manual
