GE Multilin L60 Line Phase Comparison System 5-1475 SETTINGS 5.5 GROUPED ELEMENTS5• POS SEQ di/dt FDL PICKUP: This setting controls pickup of the low set stage of the element used to control the keyoperation. Nominal current of the phase CT bank of the relay is 1 pu.• POS SEQ di/dt FDL SEAL-IN: This setting defines seal-in time of the FDL function. To equalize the response betweenall terminals of the line, the timer is started at the rising edge of the raw di / dt condition.• POS SEQ di/dt FDH PICKUP: This setting controls pickup of the high set stage of the element used to control the tripoperation. Nominal current of the phase CT bank of the relay is 1pu.• POS SEQ di/dt FDH SEAL-IN: This setting defines seal-in time of the function. To equalize the response between allterminals of the line, the timer is started at the rising edge of the raw di / dt condition. In this way, the fault detectorsreset approximately at the same time at all line terminals, regardless of responses of individual raw conditions poten-tially different at different line terminals.• POS SEQ FDH SUPV: This setting provides seal-in control of the FDH function for the symmetrical external three-phase faults starting as non-symmetrical defined by the POS SEQ DI/DT FDH SEAL-IN setting time. The overreaching dis-tance function should typically be assigned with this setting.• POS SEQ di/dt BLK: Note that the fault detector is hard-wired to the 87PC scheme. It can be disabled permanentlyusing the function setting, or blocked temporarily using this block setting. Select a FlexLogic operand that, if asserted,should block this fault detector.• POS SEQ di/dt FD TARGET: This setting controls targets of the function. These targets operate independently fromthe 87PC targets.• POS SEQ di/dt FD EVENTS: This setting controls event recording of the function. These events are logged indepen-dently from the 87PC events.Figure 5–55: POSITIVE-SEQUENCE CURRENT RATE OF CHANGE FAULT DETECTOR LOGIC831801A2.CDR| I_1 - I_1* |(summedcurrent)FAST MEASUREMENTSF1 PHASE CT BANK:Pos-seq current, I_1L1 PHASE CT BANK:Pos-seq current, I_1SETTINGSPOS SEQ di/dtFDL PICKUP:POS SEQ di/dtFDH PICKUP:> FDL PICKUP> FDH PICKUP 87PC dI1/dt FDH OPHardwired to the87PC functionRUNANDEnabled = 1Off = 0SETTINGSPOS SEQ di/dtFD FUNCTION:POS SEQ di/dtBLK:(*) value delayedby 0.5 cycle0t DPOTIMERSPOS SEQ di/dtFDL SEAL-IN:0t DPO87PC dI1/dt FDL OPFLEXLOGICOPERANDSPOS SEQ di/dtFDH SEAL-IN:ORANDSETTINGSPOS SEQ FDHSUPV:Off = 0Σ
