Neutral Overcurrent; Winding 1 (2/3) Neutral Time Overcurrent - GE 745 TRANSFORMER MANAGEMENT RELAY Instruction Manual

5 SETPOINTS
In the 745, "neutral" refers to residual current (3 I
phases. This section contains the settings to configure the neutral overcurrent elements. Included are neutral
time overcurrents for each winding, and two levels of neutral instantaneous overcurrent for each winding.
S NEUTRAL OC
S [ENTER] for more
a) WINDING 1 (2/3) NEUTRAL TIME OVERCURRENT
S W1 NTRL TIME OC
S [ENTER] for more
W1 NEUTRAL TIME OC
FUNCTION: Enabled
W1 NEUTRAL TIME OC
TARGET: Latched
W1 NEUTRAL TIME OC
PICKUP: 0.85 x CT
W1 NEUTRAL TIME OC
SHAPE: Ext Inverse
W1 NEUTRAL TIME OC
MULTIPLIER: 1.00
W1 NEUTRAL TIME OC
RESET: Linear
W1 NEUTRAL TIME OC
BLOCK: Disabled
GE Power Management
), which is calculated internally as the vector sum of the three
0
This message indicates the start of the NEUTRAL OVERCURRENT section. To
continue with these setpoints press
next section.
This message indicates the start of the NEUTRAL TIME OVERCURRENT section
for Winding 1 (2/3). To continue with these setpoints press
to go to the next section.
M E SSA G E
Range: Disabled / Enabled
Range: Self-reset / Latched / None
Select None to inhibit the display of the target message when the element
operates. Thus an element whose "target type" is None will never disable the
LED self-test feature because can not generate a displayable target
message.
Range: 0.05 to 20.00 (steps of 0.01)
Enter the level of neutral current (in units of relay nominal current) above
which the W1 (2/3) neutral time overcurrent element will pickup and start
timing.
Range: Ext Inverse / Very Inverse / Norm Inverse / Mod Inverse / Definite
Time / IEC Curve A / IEC Curve B / IEC Curve C / IEC Short Inv /
IAC Ext Inv / IAC Very Inv / IAC Inverse / IAC Short Inv / FlexCurve
A / FlexCurve B / FlexCurve C
Select the time overcurrent curve shape to be used for the W1 (2/3) neutral
time overcurrent element. Section 5.9: TIME OVERCURRENT CURVES on
page 5–91 describes the time overcurrent curve shapes.
Range: 0.00 to 100.00 (steps of 0.01)
Enter the multiplier constant by which the selected time overcurrent curve
shape (the base curve) is to be shifted in time.
Range: Instantaneous / Linear
Select Linear reset to coordinate with electromechanical time overcurrent
relays, in which the reset characteristic (when the current falls below the
reset threshold before tripping) is proportional to ratio of "energy"
accumulated to that required to trip. Select Instantaneous reset to coordinate
with relays, such as most static units, with instantaneous reset
characteristics.
Range: Disabled / Logc Inpt 1 (2-16) /Virt Inpt 1 (2-16) / Output Rly 1 (2-8) /
SelfTest Rly / Virt Outpt 1 (2-5)
745 Transformer Management Relay
5.6 S4 ELEMENTS

5.6.7 NEUTRAL OVERCURRENT

, or press to go to the
E N TE R
M E SSA G E
EN TE R
, or press
5
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