GE L60 Instruction Manual page 264

5.5 GROUPED ELEMENTS
g) NEGATIVE-SEQUENCE OVERCURRENT FAULT DETECTION
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PATH: SETTINGS GROUPED ELEMENTS
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NEGATIVE-SEQUENCE CURRENT
 NEGATIVE-SEQUENCE
 CURRENT
The negative-sequence overcurrent advanced fault detector element responds to the increment of the magnitude of the
negative-sequence current over a specified threshold. Thresholds are provided for low-set control of keying and high-set
operation control of tripping.
The following settings are available.
• NEG SEQ I_2 FD FUNCTION: This setting enables or disables the negative-sequence overcurrent fault detection.
5
Note that all fault detectors operate in parallel with the 87PC function. To effectively disable the overcurrent fault detec-
tors under the main 87PC menu, set their threshold very high.
• NEG SEQ I_2 FDL PICKUP: This setting specifies the pickup of the low-set stage of the element used to control the
key operation. The nominal current of the phase CT bank of the relay is 1 pu.
• NEG SEQ I_2 FDH PICKUP: This setting specifies the pickup of the high-set stage of the element used to control the
trip operation. The nominal current of the phase CT bank of the relay is 1 pu.
• NEG SEQ I_2 BLK: The fault detector is hard-wired to the 87PC scheme. It can be disabled permanently using the
function setting or blocked temporarily with this setting. This setting selects a FlexLogic™ operand that blocks this fault
detector when asserted.
• NEG SEQ I_2 FD TARGET: This setting controls targets of the negative-sequence overcurrent advanced fault detector
function. These targets operate independently from the 87PC targets.
• NEG SEQ I_2 FD EVENTS: This setting controls event recording of the negative-sequence overcurrent advanced fault
detector function. These events are logged independently from the 87PC events.
SETTINGS
NEG SEQ I_2 FD FUNCTION
Disabled = 0
NEG SEQ I_2 BLOCK
FAST MEASUREMENTS
F1 PHASE CT BANK
Negative-sequence
L1 PHASE CT BANK
Negative-sequence
Figure 5–50: NEGATIVE-SEQUENCE OVERCURRENT ADVANCED FAULT DETECTOR LOGIC
5-126
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PHASE COMPARISON ELEMENTS
NEG SEQ I_2 FD
FUNCTION: Disabled
NEG SEQ I_2 FDL
MESSAGE
PICKUP: 0.10 pu
NEG SEQ I_2 FDH
MESSAGE
PICKUP: 0.50 pu
NEG SEQ I_2 BLK:
MESSAGE
Off
NEG SEQ I_2 FD
MESSAGE
TARGET: Self-reset
NEG SEQ I_2 FD
MESSAGE
EVENTS: Disabled
Enabled = 1
AND
SETTINGS
Off = 0
NEG SEQ I_2 FDL PICKUP
NEG SEQ I_2 FDH PICKUP
RUN
> (FDL PICKUP) / 4
current I_2
> (FDH PICKUP) / 4
> (FDL PICKUP) / 4
current I_2
> (FDH PICKUP) / 4
Σ
L60 Line Phase Comparison System
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ADVANCED FAULT DETECTORS
Range: Disabled, Enabled
Range: 0.02 to 5.00 pu in steps of 0.01
Range: 0.05 to 15.00 pu in steps of 0.01
Range: FlexLogic™ operand
Range: Self-Reset, Latched, Disabled
Range: Disabled, Enabled
To square pulse
and transmit logic
OR
OR
> FDL PICKUP
> FDH PICKUP
5 SETTINGS
Hardwired to the
87PC function
FLEXLOGIC OPERANDS
87PC I_2 FDL OP
AND
87PC I_2 FDH OP
AND
831030A1.CDR
GE Multilin