5-378 D60 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUALCONTROL ELEMENTS CHAPTER 5: SETTINGS55.8.14.4 Permissive over-reaching transfer trip (POTT1)SETTINGS CONTROL ELEMENTS PILOT SCHEMES POTT1 SCHEMEThe POTT1 pilot scheme operates the same way as the POTT scheme, except hard-coded connections to phase andground distance elements are removed to allow the user to choose directional elements, for example ground OCdirectional elements. This allows a user to apply the POTT1 scheme using solely directional elements to achieve bettercoordination, rather than mixing distance and ground OC directional elements together. POTT 1 SCHEME POTT1 SCHEMEFUNCTION: DisabledRange: Disabled, Enabled POTT1 SCHEME BLOCK:OffRange: FlexLogic operand POTT1 PERMISSIVEECHO: DisabledRange: Disabled, Enabled, Custom POTT1 ECHO COND:OffRange: FlexLogic operand POTT1 RX PICKUPDELAY: 0.000 sRange: 0.000 to 65.535 s in steps of 0.001 TRANS BLOCK PICKUPDELAY: 0.020 sRange: 0.000 to 65.535 s in steps of 0.001 TRANS BLOCK RESETDELAY: 0.090 sRange: 0.000 to 65.535 s in steps of 0.001 ECHO DURATION:0.100 sRange: 0.000 to 65.535 s in steps of 0.001 ECHO LOCKOUT:0.250 sRange: 0.000 to 65.535 s in steps of 0.001 LINE END OPEN PICKUPDELAY: 0.050 sRange: 0.000 to 65.535 s in steps of 0.001 POTT1 SEAL-INDELAY: 0.010 sRange: 0.000 to 65.535 s in steps of 0.001 DIR FWD1:OffRange: FlexLogic operand DIR FWD2:OffRange: FlexLogic operand DIR FWD3:OffRange: FlexLogic operand POTT1 NO OF COMMBITS: 1Range: 1, 2, or 4 POTT1 RX1:OffRange: FlexLogic operand POTT1 RX2:OffRange: FlexLogic operand POTT1 RX3:OffRange: FlexLogic operand POTT1 RX4:OffRange: FlexLogic operand POTT1 SCHEME TARGET:Self-ResetRange: Self-Reset, Latched, Disabled POTT1 SCHEME EVENT:DisabledRange: Disabled, Enabled
