GE L90 Instruction Manual page 436

GROUPED ELEMENTS
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):
NEUTRAL IOC1 FUNCTION
NEUTRAL IOC1 SIGNAL SOURCE
element.
NEUTRAL IOC1 PICKUP
NEUTRAL IOC1 PICKUP DELAY
coordination with other elements and relays.
NEUTRAL IOC1 RESET DELAY
between the operate output state and the return to logic 0 after the input passes outside the defined pickup range. This
setting is used to ensure that the relay output contacts are closed long enough to ensure reception by downstream
equipment.
NEUTRAL IOC1 BLOCK
overcurrent element.
NEUTRAL IOC1 EVENTS
sequence of events recorder.
5
5.7.9.4 Neutral directional overcurrent (ANSI 67N, IEC PDEF/PTOC)
SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEUTRAL CURRENT  NEUTRAL DIRECTIONAL
OC1(2)
 NEUTRAL
 DIRECTIONAL OC1
5-250
— This setting enables and disables the neutral instantaneous overcurrent protection element.
— This setting selects the signal source for the neutral instantaneous overcurrent protection
— This setting specifies the neutral instantaneous overcurrent pickup level in per-unit values.
— This setting delays the assertion of the
— This setting specifies a delay for the reset of the neutral instantaneous overcurrent element
— Assertion of the operand assigned to this setting blocks operation of the neutral instantaneous
— This setting enables and disables the logging of neutral instantaneous overcurrent events in the
Figure 5-135: Neutral IOC1 logic
NEUTRAL DIR OC1

FUNCTION: Disabled
NEUTRAL DIR OC1

SOURCE: SRC 1
NEUTRAL DIR OC1

POLARIZING: Voltage
NEUTRAL DIR OC1 POL

VOLT: Calculated V0
NEUTRAL DIR OC1 OP

CURR: Calculated 3I0
NEUTRAL DIR OC1 POS-

SEQ RESTRAINT: 0.063
operands. It is used to achieve timing
NEUTRAL IOC OP
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: Voltage, Current, Dual, Dual-V, Dual-I
Range: Calculated V0, Measured VX
Range: Calculated 3I0, Measured IG
Range: 0.000 to 0.500 in steps of 0.001
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
CHAPTER 5: SETTINGS
Eq. 5-24