Function Range or value AccuracyMinimum polarizing voltage, Zerosequence(1–100)% ofUBase ± 0.5% of UrMinimum polarizing voltage,Negative sequence(1–100)% ofUBase ± 0.5% of UrMinimum polarizing current, Zerosequence(2–100)% ofIBase ±1.0% of IrMinimum polarizing current,Negative sequence(2–100)% ofIBase ±1.0% of IrReal part of source Z used forcurrent polarization(0.50-1000.00) W/phase -Imaginary part of source Z usedfor current polarization(0.50–3000.00) W/phase -Operate time, non-directionalstart function30 ms typically at 0.5 to 2 x Iset -Reset time, non-directional startfunction30 ms typically at 2 to 0.5 x Iset -Operate time, directional startfunction30 ms typically at 0,5 to 2 x IN -Reset time, directional startfunction30 ms typically at 2 to 0,5 x IN -1) Note: Timing accuracy only valid when 2nd harmonic blocking is turned off.8.3 Sensitive directional residual overcurrent and powerprotection SDEPSDE8.3.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberSensitive directional residual overcurrent and power protectionSDEPSDE - 67N8.3.2 FunctionalityIn isolated networks or in networks with high impedance earthing, the earth faultcurrent is significantly smaller than the short circuit currents. In addition to this, themagnitude of the fault current is almost independent on the fault location in thenetwork. The protection can be selected to use either the residual current, 3I0·cosj or3I0·j, or residual power component 3U0·3I0·cos j, for operating quantity. There isalso available one non-directional 3I0 step and one non-directional 3U0 overvoltagetripping step.1MRK 502 048-UEN A Section 8Current protection203Technical manual
