GE L30 Instruction Manual page 328

5.6 GROUPED ELEMENTS
5
b) NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT (ANSI 50Q, IEC PIOC)

PATH: SETTINGS GROUPED ELEMENTS
 NEG SEQ IOC1

The negative-sequence instantaneous overcurrent element may be used as an instantaneous function with no intentional
delay or as a definite time function. The element responds to the negative-sequence current fundamental frequency phasor
magnitude (calculated from the phase currents) and applies a positive-sequence restraint for better performance: a small
portion (12.5%) of the positive-sequence current magnitude is subtracted from the negative-sequence current magnitude
when forming the operating quantity:
The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious negative-sequence cur-
rents resulting from:
5-188
Figure 5–75: NEGATIVE SEQUENCE TOC1 SCHEME LOGIC

SETTING GROUP 1(6)
NEG SEQ IOC1
FUNCTION: Disabled
NEG SEQ IOC1 SIGNAL
MESSAGE
SOURCE: SRC 1
NEG SEQ IOC1
MESSAGE
PICKUP: 1.000 pu
NEG SEQ IOC1 PICKUP
MESSAGE
DELAY:
NEG SEQ IOC1 RESET
MESSAGE
DELAY:
NEG SEQ IOC1 BLOCK:
MESSAGE
Off
NEG SEQ IOC1
MESSAGE
TARGET: Self-reset
NEG SEQ IOC1
MESSAGE
EVENTS: Disabled
I I_2 K I_1
= –
op
L30 Line Current Differential System

NEGATIVE SEQUENCE CURRENT
Range: Disabled, Enabled
Range: SRC 1, SRC 2
Range: 0.000 to 30.000 pu in steps of 0.001
Range: 0.00 to 600.00 s in steps of 0.01
0.00 s
Range: 0.00 to 600.00 s in steps of 0.01
0.00 s
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
⋅ 1 8 ⁄
where K
=
5 SETTINGS

NEG SEQ OC1(2)
(EQ 5.21)
GE Multilin