GE D90 Plus Instruction Manual page 242

GROUPED PROTECTION ELEMENTS
Phase directional overcurrent
232
Figure 202: Phase instantaneous overcurrent 1 scheme logic
The phase directional elements (one for each of phases A, B, and C) determine the phase
current flow direction for steady state and fault conditions and can be used to control the
operation of the phase overcurrent elements via the block inputs of these elements.
Figure 203: Phase A directional polarization
PLUS
D90 LINE DISTANCE PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 7: PROTECTION