CHAPTER 5: SETTINGS
CONTROL ELEMENTS
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
5-383
5
5.8.12.5 Permissive over-reaching transfer trip (POTT1)
SETTINGS
CONTROL ELEMENTS
PILOT SCHEMES
POTT1 SCHEME
The POTT1 pilot scheme operates the same way as the POTT scheme, except hard-coded connections to phase and
ground distance elements are removed to allow the user to choose directional elements, for example ground OC
directional elements. This allows a user to apply the POTT1 scheme using solely directional elements to achieve better
coordination, rather than mixing distance and ground OC directional elements together.
POTT 1 SCHEME
POTT1 SCHEME
FUNCTION: Disabled
Range: Disabled, Enabled
POTT1 SCHEME BLOCK:
Off
Range: FlexLogic operand
POTT1 PERMISSIVE
ECHO: Disabled
Range: Disabled, Enabled, Custom
POTT1 ECHO COND:
Off
Range: FlexLogic operand
POTT1 RX PICKUP
DELAY: 0.000 s
Range: 0.000 to 65.535 s in steps of 0.001
TRANS BLOCK PICKUP
DELAY: 0.020 s
Range: 0.000 to 65.535 s in steps of 0.001
TRANS BLOCK RESET
DELAY: 0.090 s
Range: 0.000 to 65.535 s in steps of 0.001
ECHO DURATION:
0.100 s
Range: 0.000 to 65.535 s in steps of 0.001
ECHO LOCKOUT:
0.250 s
Range: 0.000 to 65.535 s in steps of 0.001
LINE END OPEN PICKUP
DELAY: 0.050 s
Range: 0.000 to 65.535 s in steps of 0.001
POTT1 SEAL-IN
DELAY: 0.010 s
Range: 0.000 to 65.535 s in steps of 0.001
DIR FWD1:
Off
Range: FlexLogic operand
DIR FWD2:
Off
Range: FlexLogic operand
DIR FWD3:
Off
Range: FlexLogic operand
POTT1 NO OF COMM
BITS: 1
Range: 1, 2, or 4
POTT1 RX1:
Off
Range: FlexLogic operand
POTT1 RX2:
Off
Range: FlexLogic operand
POTT1 RX3:
Off
Range: FlexLogic operand
POTT1 RX4:
Off
Range: FlexLogic operand
POTT1 SCHEME TARGET:
Self-Reset
Range: Self-Reset, Latched, Disabled
POTT1 SCHEME EVENT:
Disabled
Range: Disabled, Enabled