GE L90 Instruction Manual page 293

5 SETTINGS
Figure 5–82: LOAD ENCROACHMENT APPLIED TO DISTANCE ELEMENT
• LOAD ENCROACHMENT MIN VOLT: This setting specifies the minimum positive-sequence voltage required for oper-
ation of the element. If the voltage is below this threshold a blocking signal will not be asserted by the element. When
selecting this setting one must remember that the L90 measures the phase-to-ground sequence voltages regardless of
the VT connection.
The nominal VT secondary voltage as specified with the
setting is the per-unit base for this setting.
VT SECONDARY
• LOAD ENCROACHMENT REACH: This setting specifies the resistive reach of the element as shown in the Load
encroachment characteristic diagram. This setting should be entered in secondary ohms and be calculated as the pos-
itive-sequence resistance seen by the relay under maximum load conditions and unity power factor.
• LOAD ENCROACHMENT ANGLE: This setting specifies the size of the blocking region as shown on the Load
encroachment characteristic diagram and applies to the positive-sequence impedance.
SETTING
LOAD ENCROACHMENT
FUNCTION:
Disabled=0
Enabled=1
SETTING
LOAD ENCRMNT BLK:
Off=0
SETTING SETTING
LOAD ENCROACHMENT LOAD ENCROACHMENT
SOURCE: MIN VOLT:
Pos Seq Voltage (V_1) V_1 > Pickup
Pos Seq Current (I_1)
GE Multilin
X
SYSTEM SETUP
SETTINGS
LOAD ENCROACHMENT
REACH:
LOAD ENCROACHMENT
ANGLE:
RUN
AND
Load Encroachment
Characteristic
Figure 5–83: LOAD ENCROACHMENT SCHEME LOGIC
L90 Line Current Differential System
5.6 GROUPED ELEMENTS
R
837731A1.CDR
AC INPUTS VOLTAGE BANK X5
SETTINGS
LOAD ENCROACHMENT
PKP DELAY:
LOAD ENCROACHMENT
RST DELAY:
t
PKP
t
RST
PHASE
5
FLEXLOGIC OPERANDS
LOAD ENCHR PKP
LOAD ENCHR DPO
LOAD ENCHR OP
827847A2.CDR
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