GE 745 TRANSFORMER MANAGEMENT RELAY User Manual

GE Power Management 745 Transformer Management Relay 5-63
5 SETPOINTS 5.6 S4 ELEMENTS
5
5.6.10 NEGATIVE SEQUENCE OVERCURRENT
This section contains the settings to configure the negative sequence overcurrent elements. Included are neg-
ative sequence time overcurrents for each winding, and negative sequence instantaneous overcurrents for
each winding.
a) WINDING 1 (2/3) NEGATIVE SEQUENCE TIME OVERCURRENT
y NEG SEQ OC
y
[ENTER] for more
This message indicates the start of the
NEGATIVE SEQUENCE OVERCURRENT
section. To continue with these setpoints press , or press to
go to the next section.
y W1 NEG SEQ TIME OC
y
[ENTER] for more
This message indicates the start of the
NEGATIVE SEQUENCE TIME
OVERCURRENT
section for Winding 1 (2/3). To continue with these setpoints
press , or press to go to the next section.
W1 NEG SEQ TIME OC
FUNCTION: Disabled
Range: Disabled / Enabled
W1 NEG SEQ TIME OC
TARGET: Latched
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
never disables the
LED self-test feature since it cannot generate a displayable target message.
W1 NEG SEQ TIME OC
PICKUP: 0.25 x CT
Range: 0.05 to 20.00 (steps of 0.01)
Enter the level of negative sequence current (in units of relay nominal
current) above which the W1 (2/3) negative sequence time overcurrent
element will pickup and start timing.
W1 NEG SEQ TIME OC
SHAPE: Ext Inverse
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) negative
sequence time overcurrent element. Section 5.9: TIME OVERCURRENT
CURVES on page 5–91 describes the time overcurrent curve shapes.
W1 NEG SEQ TIME OC
MULTIPLIER: 1.00
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.
W1 NEG SEQ TIME OC
RESET: Linear
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.
W1 NEG SEQ TIME OC
BLOCK: Disabled
Range: Disabled / Logc Inpt 1 (2-16) /Virt Inpt 1 (2-16) / Output Rly 1 (2-8) /
SelfTest Rly / Virt Outpt 1 (2-5)
ENTER
MESSAGE
ENTER
MESSAGE

GE 745 TRANSFORMER MANAGEMENT RELAY Specifications

General

Brand	GE
Model	745 TRANSFORMER MANAGEMENT RELAY
Category	Relays
Language	English