CHAPTER 5: SETTINGS
GROUPED ELEMENTS
L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUAL
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5
The element responds to the magnitude of the I_2 × Z – V_2 voltage term in the signal source associated with the 87PC
function. The impedance factor is controlled by an independent setting. Two voltage thresholds are provided for the low-
set and high-set operation controlling keying and tripping, respectively.
NEG SEQ VOL FD FUNCTION
— This setting enables or disables the negative-sequence voltage fault detection. Note that all
fault detectors operate in parallel toward the 87PC function. If not required, disable a given fault detector. To effectively
disable the overcurrent fault detectors under the main 87PC menu, set their threshold very high. This function requires
voltages to operate, and uses the first voltage bank configured in the relay.
For this function to operate correctly, the phase VT bank needs to be configured properly and assigned on source 3 or
source 4. The I_2 × Z – V_2 function cannot be enabled if a phase VT is not assigned at source 3 or 4. In this case this
setting is forced to “Disabled.”
NEG SEQ VOL FD IMPEDANCE
— This setting defines the relative magnitude of the I_2 × Z term augmented to the negative-
sequence voltage. The element uses the positive-sequence line impedance—both magnitude and angle—as defined under
SETTINGS
PRODUCT SETUP
FAULT REPORTS
FAULT REPORT
. This setting controls the percentage of the line
impedance used in the I_2 × Z – V_2 voltage term.
NEG SEQ VOL FDL PICKUP
— This setting controls pickup of the low-set stage used to control the key operation. The nominal
phase-to-ground voltage of the VT bank of the relay is 1 pu. For example, for a phase VT bank configured in wye and
having 63.5 V nominal secondary, or for a phase VT bank configured in delta and having 110 V nominal secondary, 1 pu is
equivalent to 63.5 V.
NEG SEQ VOL FDH PICKUP
— This setting controls pickup of the high-set stage used to control the trip operation. The nominal
phase-to-ground voltage of the VT bank of the relay is 1 pu.
NEG SEQ VOL FD BLK
— The fault detector is hard-wired to the 87PC scheme. It can be disabled permanently using the
function setting or blocked temporarily using this block setting. Indicate a FlexLogic operand to block the negative-
sequence voltage fault detector upon assertion.
NEG SEQ VOL FD TARGET
— This setting controls the targets of the function. These targets operate independently from the
87PC targets.
NEG SEQ VOL FD EVENTS
— This setting controls event recording of the function. These events are logged independently from
the 87PC events.
Figure 5-77: Negative-sequence voltage fault detector logic
NEG SEQ VOL FD BLK:
Off
Range: any FlexLogic operand
NEG SEQ VOL FD
TARGET: Self-reset
Range: Self-Reset, Latched, Disabled
NEG SEQ VOL FD
EVENTS: Disabled
Range: Disabled, Enabled
FAST MEASUREMENTS
F1 PHASE CT BANK:
Neg-seq current, I_2
SETTINGS
NEG SEQ VOL
FD IMPEDANCE:
L1 PHASE CT BANK:
Neg-seq current, I_2
| I_2*Z - V_2 |
(summed
current)
L5 PHASE VT BANK:
Neg-seq voltage, V_2
FAULT REPORT
1 Z1 MAG:
FAULT REPORT
1 Z1 ANGLE:
SETTINGS
NEG SEQ VOL
FDL PICKUP:
> FDL PICKUP
NEG SEQ VOL
FDH PICKUP
> FDH PICKUP
87PC V2 FDL OP
FLEXLOGIC OPERAND
87PC V2 FDH OP
Hardwired to the
87PC function
RUN
AN
D
Enabled = 1
Off = 0
SETTINGS
NEG SEQ VOL
FD FUNCTION:
NEG SEQ VOL
FD BLK:
Σ
831799A2.CDR
