GE 850 Instruction Manual page 335

CHAPTER 6: PROTECTION SETPOINTS
REV Operating
Region
-I_2 line
-ECA line
VCG
FASTPATH:
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
Figure 6-26: Negative Sequence Directional Characteristic
-V_2 line
REV FWD
LA LA
LA
LA
V_2 line
The forward-looking function is designed to be more secure compared to the reverse-
looking function, and should therefore be used for the tripping direction. The reverse-
looking function is designed to be faster compared to the forward-looking function and
should be used for the blocking direction. This allows better protection coordination. The
above bias should be taken into account when using the Negative Sequence Directional
Overcurrent element to directionalize other protection elements.
Path: Setpoints > Protection > Group 1(6) > Current > Negative Sequence Dir OC 1(X)
FUNCTION
Range: Disabled, Enabled
Default: Disabled
SIGNAL INPUT
Range: dependant upon the order code
Default: CT Bank 1 -J1
This setting provides a selection for the CT Bank input.
The "Current Input" setting is omitted for 850 which is defaulted to CT Bank 1-J1.
VAG (reference)
LA
ECA
LA
REV FWD
LA LA
CURRENT ELEMENTS
ECA line
I_2 line
FWD Operating
Region
VBG
827806A2.CDR
6–67