6.12 Negative sequence based overcurrent functionDNSPTOC (46)6.12.1 IdentificationFunction description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberNegative sequence based overcurrentfunctionDNSPTOC3I2>IEC09000132 V2 EN466.12.2 FunctionalityNegative sequence based overcurrent function DNSPTOC (46) may be used in power lineapplications where the reverse zero sequence source is weak or open, the forward sourceimpedance is strong and it is desired to detect forward ground faults.Additionally, it is applied in applications on cables, where zero sequence impedancedepends on the fault current return paths, but the cable negative sequence impedance ispractically constant.The directional function is current and voltage polarized. The function can be set toforward, reverse or non-directional independently for each step. Both steps are providedwith a settable definite time delay.DNSPTOC (46) protects against all unbalanced faults including phase-to-phase faults.The minimum pickup current of the function must be set to above the normal systemunbalance level in order to avoid inadvertent tripping.Section 6 1MRK 511 287-UUS ACurrent protection162Technical manual
