GE b30 - Ground Current

5-154 B30 Bus Differential System GE Multilin
5.6 GROUPED ELEMENTS 5 SETTINGS
5
• System unbalances under heavy load conditions
• Transformation errors of current transformers (CTs) during double-line and three-phase faults
• Switch-off transients during double-line and three-phase faults
The positive-sequence restraint must be considered when testing for pickup accuracy and response time (multiple of
pickup). The operating quantity depends on how test currents are injected into the relay (single-phase injection):
(EQ 5.13)
Figure 5–57: NEUTRAL IOC1 SCHEME LOGIC
5.6.6 GROUND CURRENT
a) GROUND TIME OVERCURRENT (ANSI 51G, IEC PTOC)
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  GROUND CURRENT  GROUND TOC1(6)
 GROUND TOC1

GROUND TOC1
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
GROUND TOC1 SIGNAL
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
MESSAGE
GROUND TOC1
INPUT: Phasor
Range: Phasor, RMS
MESSAGE
GROUND TOC1
PICKUP: 1.000 pu
Range: 0.000 to 30.000 pu in steps of 0.001
MESSAGE
GROUND TOC1
CURVE: IEEE Mod Inv
Range: see the Overcurrent Curve Types table
MESSAGE
GROUND TOC1
TD MULTIPLIER: 1.00
Range: 0.00 to 600.00 in steps of 0.01
MESSAGE
GROUND TOC1
RESET: Instantaneous
Range: Instantaneous, Timed
MESSAGE
GROUND TOC1 BLOCK:
Off
Range: FlexLogic operand
MESSAGE
GROUND TOC1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
GROUND TOC1
EVENTS: Disabled
Range: Disabled, Enabled
I
op
1
3
---
3 K–()× x I
injected
=
FLEXLOGIC OPERANDS
NEUTRAL IOC1 FUNCTION:
NEUTRAL IOC1 PICKUP:
NEUTRAL IOC1 SOURCE:
NEUTRAL IOC1 BLOCK:
NEUTRAL IOC1 DPO
NEUTRAL IOC1 OP
NEUTRAL IOC1 PKP
RUN
AND
827035A5.CDR
SETTING
SETTING
Enabled=1
SETTING
SETTING
I_0
Off=0
SETTINGS
NEUTRAL IOC1
RESET DELAY :
NEUTRAL IOC1
PICKUP DELAY :
t
PKP
t RST
3( I_0 - K I_1 ) PICKUP