GE C60 Instruction Manual

Also see for C60: Communications manual Communications guide Instruction manual Instruction manual Instruction manual

Contents

CHAPTER 5: SETTINGS CONTROL ELEMENTSC60 BREAKER PROTECTION SYSTEM – INSTRUCTION MANUAL 5-2415START TMR Z2GR Inp1 and START TMR Z2GR Inp2 — These settings select an operand that starts the ground distance zone 2timer to avoid a trip delay if the fault evolves from one zone of protection to another zone of protection (for example, fromzone 3 to zone 2). For instance, the GND DIST Z3 PKP FlexLogic operand can be assigned to these settings. Use a FlexLogicOR-gate if more than two inputs are required. See the ground distance logic diagrams for information.PH SELECTOR RST DELAY — This setting specifies the reset delay of the Phase Selector element outputs after systemdisturbance occurs. This delay has to be long enough to allow elements assigned to cause single-pole tripping to operate.If, for example, it is intended that distance zone 2 with a time delay of 0.5 seconds causes a single-pole trip, then thissetting has to be at least 0.6 seconds.PH SELECTOR RESET — This setting selects an operand to reset the Phase Selector element. The selected operand is ORedwith the OPEN POLE OP operand internally to reset the phase selector element. See the Phase Selection section in the Theoryof Operation chapter for details.TRIP FORCE 3-POLE — Selects an operand that forces an input selected for single pole operation to produce a three-poleoperation. The AR DISABLED FlexLogic operand is the recommended value for this setting. Power system configurations orconditions that require such operations can be considered as well.TRIP PILOT PRIORITY — This setting is used to set an interval equal to the inter-relay channel communications time, plus amargin, during which outputs are not asserted. This delay permits fault identification information from a remote terminalto be used instead of local data only.REVERSE FAULT — Use this setting to guarantee accuracy of single-pole tripping under evolving external to internal faults.When a close-in external fault occurs, the relay is biased toward very fast operation on a following internal fault. This isprimarily due to depressed voltages and elevated currents in response to the first, external fault. The phase selector canexhibit some time lag compared to the main protection elements. This can potentially result in a spurious three-poleoperation on a single-line-to-ground internal fault. Delaying tripping on internal faults that follow detection of reversefaults solves the problem.As long as the operand indicated under this setting is asserted the trip action is delayed by TRIP DELAY ON EVOLV FAULTStime. Typically this operand should combine reverse zone indications (such as zone 4 pickup) with a half-cycle pickup delay,and two-cycle dropout delay. Use this setting only in single-pole tripping applications, when evolving faults are ofimportance, and slightly delayed operation on evolving faults can be traded for enhanced accuracy of single-pole tripping.TRIP DELAY ON EVOLV FAULTS — Use this setting in conjunction with the preceding REVERSE FAULT setting. Typically this valueis set around half a power system cycle. Use it only in single-pole tripping applications, when evolving faults are ofimportance, and slightly delayed operation on evolving faults can be traded for enhanced accuracy of single-pole tripping.BKR ΦA OPEN, BKR ΦB OPEN, and BKR ΦC OPEN — These settings are used to select an operand to indicates that phase A, B, orC of the breaker is open, respectively.