GE L90 Instruction Manual page 504

GROUPED ELEMENTS
5.7.11.2 Ground time overcurrent (ANSI 51G, IEC PTOC)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  GROUND CURRENT  GROUND TOC1(6)
 GROUND TOC1

5
This element can provide a required time-delay operating characteristic versus the applied current or be used as a simple
definite time element. The ground current input value is the quantity measured by the ground input CT and is the
fundamental phasor or RMS magnitude. Two methods of resetting operation are available: "Timed" and "Instantaneous"
(see the Inverse TOC Curve Characteristics section for details). When the element is blocked, the time accumulator resets
according to the reset characteristic. For example, if the element reset characteristic is set to "Instantaneous" and the
element is blocked, the time accumulator clears immediately.
GROUND TOC1 FUNCTION
GROUND TOC1 SIGNAL SOURCE
GROUND TOC1 INPUT
selected as fundamental phasor magnitudes or total waveform RMS magnitudes as required by the application.
GROUND TOC1 PICKUP
GROUND TOC1 CURVE
5-280
 GROUND TOC6


 GROUND IOC1


 GROUND IOC12


 RESTRICTED GROUND

 FAULT1
 RESTRICTED GROUND

 FAULT4
GROUND TOC1

FUNCTION: Disabled
GROUND TOC1 SIGNAL

SOURCE: SRC 1
GROUND TOC1

INPUT: Phasor
GROUND TOC1

PICKUP: 1.000 pu
GROUND TOC1

CURVE: IEEE Mod Inv
GROUND TOC1

TD MULTIPLIER: 1.00
GROUND TOC1

RESET: Instantaneous
GROUND TOC1 BLOCK:

Off
GROUND TOC1

TARGET: Self-reset
GROUND TOC1

EVENTS: Disabled
— This setting enables and disables the ground time overcurrent protection element.
— This setting selects the signal source for the ground time overcurrent protection element.
— This setting selects how ground current input quantities are interpreted by the L90. Inputs can be
— This setting specifies the ground time overcurrent pickup level in per-unit values.
— This setting selects the inverse time overcurrent curve style.
See page 5-281

See page 5-282

Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: Phasor, RMS
Range: 0.020 to 30.000 pu in steps of 0.001
Range: see the Overcurrent Curve Types table
Range: 0.00 to 600.00 in steps of 0.01
Range: Instantaneous, Timed
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
Range: Disabled, Enabled
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS