CHAPTER 5: SETTINGS GROUPED ELEMENTSF60 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL 5-2275The negative-sequence time overcurrent element can be used to determine and clear unbalance in the system. The inputfor calculating negative-sequence current is the fundamental phasor value.Two methods of resetting operation are available; “Timed” and “Instantaneous” (see the Inverse TOC Curve Characteristicssection earlier for details on curve setup, trip times and reset operation). When the element is blocked, the timeaccumulator resets according to the reset characteristic. For example, if the element reset characteristic is set to“Instantaneous” and the element is blocked, the time accumulator clears immediately.Figure 5-117: Negative sequence TOC1 logic5.7.8.3 Negative sequence instantaneous overcurrent (ANSI 50Q, IEC PIOC)SETTINGS GROUPED ELEMENTS SETTING GROUP 1(6) NEGATIVE SEQUENCE CURRENT NEG SEQ OC1(2) NEG SEQ TOC1PICKUP: 1.000 puRange: 0.020 to 30.000 pu in steps of 0.001 NEG SEQ TOC1CURVE: IEEE Mod InvRange: see Overcurrent Curve Types table NEG SEQ TOC1TD MULTIPLIER: 1.00Range: 0.00 to 600.00 in steps of 0.01 NEG SEQ TOC1RESET: InstantaneousRange: Instantaneous, Timed NEG SEQ TOC1 BLOCK:OffRange: FlexLogic operand NEG SEQ TOC1TARGET: Self-resetRange: Self-reset, Latched, Disabled NEG SEQ TOC1EVENTS: DisabledRange: Disabled, Enabled NEG SEQ IOC1 NEG SEQ IOC1FUNCTION: DisabledRange: Disabled, Enabled NEG SEQ IOC1 SIGNALSOURCE: SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4 NEG SEQ IOC1PICKUP: 1.000 puRange: 0.020 to 30.000 pu in steps of 0.001 NEG SEQ IOC1 PICKUPDELAY: 0.00 sRange: 0.00 to 600.00 s in steps of 0.01
