GE L90 Instruction Manual

Also see for L90: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

5-244 L90 Line Current Differential System GE Multilin5.7 CONTROL ELEMENTS 5 SETTINGS5• TRIP MODE: This setting is used to select the required mode of operation. If selected to “3 Pole Only” outputs for allthree phases are always set simultaneously. If selected to “3 Pole & 1 Pole” outputs for all three phases are set simul-taneously unless the phase selector or a pilot aided scheme determines the fault is single-phase-to-ground. If the faultis identified as being AG, BG or CG only the operands for the faulted phase will be asserted.• TRIP 3-POLE INPUT-1 to TRIP 3-POLE INPUT-6: These settings are used to select an operand representing a faultcondition that is not desired to initiate a single pole operation (for example, phase undervoltage). Use a FlexLogic OR-gate if more than six inputs are required.• TRIP 1-POLE INPUT-1 to TRIP 1-POLE INPUT-6: These settings are used to select an operand representing a faultcondition that is desired to initiate a single pole trip-and-reclose if the fault is single phase to ground (for example, dis-tance zone 1). Use a FlexLogic™ OR-gate if more than six inputs are required. The inputs do not have to be phase-specific as the phase selector determines the fault type.The AR FORCE 3-P TRIP operand is asserted by the autorecloser 1.5 cycles after single-pole reclosing is initiated. Thisoperand calls for a three-pole trip if any protection element configured under TRIP 1-POLE INPUT remains picked-up. Theopen pole detector provides blocking inputs to distance elements, and therefore the latter will reset immediately afterthe TRIP 1-POLE operand is asserted. For other protection elements used in single-pole tripping, the user must ensurethey will reset immediately after tripping, otherwise the fact that they are still picked up will be detected as an evolvingfault and the relay will trip three-poles. For example, if high-set phase instantaneous overcurrent is used (TRIP 1-POLEINPUT X: “ PHASE IOC1 OP”), then OPEN POLE OP A shall be used for blocking phase A of the instantaneous overcur-rent element. In this way, after tripping phase A, the phase a instantaneous overcurrent element is forced to reset.Phases B and C are still operational and can detect an evolving fault as soon as 8 ms after tripping phase A. Neutraland negative-sequence instantaneous overcurrent elements shall be blocked from the OPEN POLE BLK N operandunless the pickup setting is high enough to prevent pickup during single-pole reclosing.• TRIP RECLOSE INPUT-1 to TRIP RECLOSE INPUT-6: These settings select an operand representing a fault condi-tion that is desired to initiate three pole reclosing (for example, phase distance zone 1). Use a FlexLogic™ OR-gate ifmore than six inputs are required. These inputs will also include the TRIP 1-POLE INPUT-1 to TRIP 1-POLE INPUT-6 values,which are intended to initiate three-pole reclosing in situations where single-pole tripping commands are changed tothree-pole tripping commands. This may happen in cases where the phase selector identifies a multi-phase fault or theAR FORCE 3P TRIP command is present.• TRIP SEAL-IN DELAY: This setting specifies the minimum time that trip command signals are maintained to providesufficient time to open the breaker poles. If a value of “0” is specified, then the output signal is reset once the protectionelements initiating the trip are reset. If a value other than “0” is specified, then the protection elements must reset andthe timer initiated at the first trip command must expire.• TRIP RESET: This setting selects the option to reset the trip latches. If “Pole Curr OR Custom” is chosen, then theOPEN POLE CURRENT PKP setting should be programmed accordingly. If “CBaux OR Custom” is chosen, then the break-ers should be set appropriately. Both the “Current” and “CBaux” options can be complimented by custom conditionsusing the BKR ΦA OPEN, BKR ΦB OPEN, and BKR ΦC OPEN settings indicated below. Alternately, a purely custom condi-tion can be applied to reset trip output latches.• START TMR Z2PH Inp1 and START TMR Z2PH Inp2: These settings select an operand that will start the phase dis-tance zone 2 timer to avoid a trip delay if the fault evolves from one type to another type (for example, from a single-line–to-ground fault to a multi-phase fault) or from one zone of protection to another zone of protection (for example,from zone 3 to zone 2). For instance, the GND DIST Z2 PKP FlexLogic™ operand or the PH DIST Z3 PKP FlexLogic™operand could be assigned to either of these settings. Use a FlexLogic OR-gate if more than two inputs are required.Refer to phase distance logic diagrams for additional information.• START TMR Z2GR Inp1 and START TMR Z2GR Inp2: These settings select an operand that will start the ground dis-tance zone 2 timer to avoid a trip delay if the fault evolves from one zone of protection to another zone of protection (forexample, from zone 3 to zone 2). For instance, the GND DIST Z3 PKP FlexLogic™ operand could be assigned to thesesettings. Use a FlexLogic OR-gate if more than two inputs are required. Refer to ground distance logic diagrams foradditional information.• BKR ΦA OPEN, BKR ΦB OPEN, and BKR ΦC OPEN: This settings are used to select an operand to indicates thatphase A, B, or C of the breaker is open, respectively.• TRIP FORCE 3-POLE: Selects an operand that will force an input selected for single pole operation to produce a threepole operation. The AR DISABLED FlexLogic™ operand is the recommended value for this setting. Power system con-figurations or conditions which require such operations may be considered as well.