CHAPTER 5: SETTINGS CONTROL ELEMENTSM60 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL 5-2515The detection of the breaker flashover is based on the following conditions:• Breaker open,• Voltage difference drop, and• Measured flashover current through the breakerFurthermore, the scheme is applicable for cases where either one or two sets of three-phase voltages are available acrossthe breaker.Three VT breaker flashover applicationWhen only one set of VTs is available across the breaker, set the BRK 1 FLSHOVR SIDE 2 SRC setting to “None.” To detect anopen breaker condition in this application, the scheme checks if the per-phase voltages were recovered (picked up), thestatus of the breaker is open (contact input indicating the breaker status is off), and no flashover current is flowing. Acontact showing the breaker status must be provided to the relay. The voltage difference is not considered as a conditionfor open breaker in this part of the logic. BKR 1 FLSHOVR SIDE 1SRC: SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4 BKR 1 FLSHOVR SIDE 2SRC: NoneRange: None, SRC 1, SRC 2, SRC 3, SRC 4 BKR 1 STATUS CLSD A:OffRange: FlexLogic operand BKR 1 STATUS CLSD C:OffRange: FlexLogic operand BKR 1 FLSHOVR V PKP:0.850 puRange: 0.000 to 1.500 pu in steps of 0.001 BKR 1 FLSHOVR DIFF VPKP: 1000 VRange: 0 to 100000 V in steps of 1 BKR 1 FLSHOVR AMPPKP: 0.600 puRange: 0.000 to 1.500 pu in steps of 0.001 BKR 1 FLSHOVR PKPDELAY: 0.100 sRange: 0.000 to 65.535 s in steps of 0.001 BKR 1 FLSHOVR SPV A:OffRange: FlexLogic operand BKR 1 FLSHOVR SPV C:OffRange: FlexLogic operand BKR 1 FLSHOVR BLOCK:OffRange: FlexLogic operand BKR 1 FLSHOVRTARGET: Self-resetRange: Self-reset, Latched, Disabled BKR 1 FLSHOVREVENTS: DisabledRange: Disabled, EnabledNOTEVoltages must be present prior to flashover conditions. If the three VTs are placed after the breaker on the line(or feeder), and the downstream breaker is open, the measured voltage is zero and the flashover element is notinitiated.
