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 primary current (IBase), primary voltage (UBase)and primary power (SBase) are set in the global base values for settings functionGBASVAL.GlobalBaseSel: This is used to select GBASVAL function for reference of basevalues.SeqTypeUPol: This is used to select the type of voltage polarising quantity i.e. Zeroseq and Neg seq for direction detection.SeqTypeIPol: This is used to select the type of current polarising quantity i.e. Zeroseq and Neg seq for direction detection.SeqTypeIDir: This is used to select the type of operating current quantity i.e. Zeroseq and Neg seq for direction detection.7.4.3.1 Common settings for all steps M15282-81 v10AngleRCA: Relay characteristic angle given in degree. This angle is defined asshown in Figure 51. 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 51: 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 504 169-UEN A Section 7Current protectionTransformer protection RET650 2.2 IEC 123Application manual
