GE D60 Instruction Manual page 536

CONTROL ELEMENTS
The settings and application guidance for the POTT scheme applies to the POTT1 scheme. See the POTT section.
— This setting defines the FlexLogic operand of a protection element used for keying the communication
DIR FWD1..3
channel and initiating operation of the scheme. Good directional integrity is the key requirement for an over-reaching
forward-looking protection element used as DIR FWD.
Even though any FlexLogic operand can be used as DIR FWD allowing the user to combine responses of various protection
elements, or to apply extra security conditions through FlexLogic equations, this signal is primarily meant to be the output
operand from either the Negative-Sequence Directional IOC or Neutral Directional IOC. Both of these elements have
separate forward (FWD) and reverse (REV) output operands. The forward indication is used (
NEUTRAL DIR OC1 FWD
5
5.8.14.5 Hybrid permissive over-reaching transfer trip
SETTINGS  CONTROL ELEMENTS  PILOT SCHEMES  HYBRID POTT SCHEME
 HYBRID POTT SCHEME

5-358
).
Figure 5-206: POTT1 (ground) scheme logic
HYB POTT SCHEME

FUNCTION: Disabled
HYB POTT BLOCK:

Off
HYB POTT PERMISSIVE

ECHO: Disabled
HYB POTT ECHO COND:

Off
NEG SEQ DIR OC1 FWD
Range: Disabled, Enabled
Range: FlexLogic operand
Range: Disabled, Enabled, Custom
Range: FlexLogic operand
D60 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
or