GE T60 User Manual

GE Multilin T60 Transformer Protection System 5-237
5 SETTINGS 5.6 GROUPED ELEMENTS
5
d) NEUTRAL DIRECTIONAL OVERCURRENT (ANSI 67N, IEC PDEF/PTOC)
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEUTRAL CURRENT  NEUTRAL DIRECTIONAL OC1
The neutral directional overcurrent element provides both forward and reverse fault direction indications the NEUTRAL DIR
OC1 FWD
and NEUTRAL DIR OC1 REV operands, respectively. The output operand is asserted if the magnitude of the oper-
ating current is above a pickup level (overcurrent unit) and the fault direction is seen as forward or reverse, respectively
(directional unit).
The overcurrent unit responds to the magnitude of a fundamental frequency phasor of the either the neutral current calcu-
lated from the phase currents or the ground current. There are separate pickup settings for the forward-looking and
reverse-looking functions. If set to use the calculated 3I_0, the element applies a positive-sequence restraint for better per-
formance: a small user-programmable portion of the positive-sequence current magnitude is subtracted from the zero-
sequence current magnitude when forming the operating quantity.
(EQ 5.38)
The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious zero-sequence currents
resulting from:
• System unbalances under heavy load conditions.
 NEUTRAL
 DIRECTIONAL OC1
NEUTRAL DIR OC1
FUNCTION: Disabled
Range: Disabled, Enabled
MESSAGE
NEUTRAL DIR OC1
SOURCE: SRC 1
Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6
MESSAGE
NEUTRAL DIR OC1
POLARIZING: Voltage
Range: Voltage, Current, Dual, Dual-V, Dual-I
MESSAGE
NEUTRAL DIR OC1 POL
VOLT: Calculated V0
Range: Calculated V0, Aux. Voltage (VX)
MESSAGE
NEUTRAL DIR OC1 OP
CURR: Calculated 3I0
Range: Calculated 3I0, Measured IG
MESSAGE
NEUTRAL DIR OC1 POS-
SEQ RESTRAINT: 0.063
Range: 0.000 to 0.500 in steps of 0.001
MESSAGE
NEUTRAL DIR OC1
OFFSET: 0.00 
Range: 0.00 to 250.00  in steps of 0.01
MESSAGE
NEUTRAL DIR OC1 FWD
ECA: 75° Lag
Range: –90 to 90° in steps of 1
MESSAGE
NEUTRAL DIR OC1 FWD
LIMIT ANGLE: 90°
Range: 40 to 90° in steps of 1
MESSAGE
NEUTRAL DIR OC1 FWD
PICKUP: 0.050 pu
Range: 0.006 to 30.000 pu in steps of 0.001
MESSAGE
NEUTRAL DIR OC1 REV
LIMIT ANGLE: 90°
Range: 40 to 90° in steps of 1
MESSAGE
NEUTRAL DIR OC1 REV
PICKUP: 0.050 pu
Range: 0.006 to 30.000 pu in steps of 0.001
MESSAGE
NEUTRAL DIR OC1 BLK:
Off
Range: FlexLogic operand
MESSAGE
NEUTRAL DIR OC1
TARGET: Self-reset
Range: Self-reset, Latched, Disabled
MESSAGE
NEUTRAL DIR OC1
EVENTS: Disabled
Range: Disabled, Enabled
I
op
3I_0K I_1–=

GE T60 Specifications

General

Brand	GE
Model	T60
Category	Relays
Language	English