7.1.3 Setting guidelines IP14982-1 v1M12982-4 v13When inverse time overcurrent characteristic is selected, the trip timeof the stage will be the sum of the inverse time delay and the setdefinite time delay. Thus, if only the inverse time delay is required, it isimportant to set the definite time delay for that stage to zero.The parameters for the directional phase overcurrent protection, four steps OC4PTOC(51/67) are set via the local HMI or PCM600.The following settings can be done for OC4PTOC (51/67).Common base IED values for primary current (IBase), primary voltage (UBase) andprimary power (SBase) are set in the global base values for settings functionGBASVAL.GlobalBaseSel: This is used to select GBASVAL function for reference of base values.MeasType: Selection of discrete Fourier filtered (DFT) or true RMS filtered (RMS)signals. RMS is used when the harmonic contents are to be considered, for example inapplications with shunt capacitors.Operation: The protection can be set to Enabled or Disabled.AngleRCA: Protection characteristic angle set in degrees. If the angle of the fault loopcurrent has the angle RCA, the direction to the fault is forward.AngleROA: Angle value, given in degrees, to define the angle sector of the directionalfunction, shown in Figure 87.NumPhSel: Number of phases, with high current, required for operation. The settingpossibilities are: 1 out of 3, 2 out of 3 and 3 out of 3. The default setting is 1 out of 3.PUMinOpPhSel: Minimum current setting level for releasing the directional startsignals in % of IB. This setting should be less than the lowest step setting. The defaultsetting is 7% of IB.2ndHarmStab: Operate level of 2nd harmonic current restrain set in % of thefundamental current. The setting range is 5 - 100% in steps of 1%. The default settingis 20%.1MRK 505 370-UUS A Section 7Current protectionBusbar protection REB670 2.2 ANSI 177Application manual
