S4 Elements
745
Transformer Management Relay
Se
tpoints
http://www.GEindustrial.com/multilin
5–54
GE Multilin
c) Winding 1(3) Phase Time Overcurrent
PATH: SETPOINTS
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S4 ELEMENTS
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PHASE OC
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W1(3) PHASE TIME OC
•
W1(3) PHASE TIME OC PICKUP
: Enter the phase current level (in units of
relay nominal current) above which the Winding 1(3) Phase Time Overcurrent
element will pickup and start timing.
•
W1(3) PHASE TIME OC SHAPE
: Select the time overcurrent curve shape to
use for the Winging 1(3) Phase Time Overcurrent.
page 5–50 describes the TOC curve shapes.
•
W1(3) PHASE TIME OC MULTIPLIER
: Enter the multiplier constant by which
the selected time overcurrent curve shape (the base curve) is to be shifted in
time.
•
W1(3) PHASE TIME OC RESET
: 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(3) HARMONIC DERATING CORRECTION
: Select “Enabled” to enable
automatic harmonic derating correction of the Winging 1(3) Phase Time
Overcurrent curve. The 745 calculates the derated transformer capability when
supplying non-sinusoidal load currents (as per ANSI / IEEE C57.110-1986) and,
when this feature is enabled, automatically shifts the phase time overcurrent
curve pickup in order to maintain the required protection margin with respect to
the transformer thermal damage curve, as illustrated below.
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W1 PHASE
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TIME OC
W1 PHASE TIME OC
FUNCTION: Enabled
Range: Enabled, Disabled
MESSAGE
W1 PHASE TIME OC
TARGET: Latched
Range: Self-Reset, Latched, None
MESSAGE
W1 PHASE TIME OC
PICKUP:
1.20 x CT
Range: 0.05 to 20.00 x CT in steps of
0.01
MESSAGE
W1 PHASE TIME OC
SHAPE: Ext Inverse
Range: see description below
MESSAGE
W1 PHASE TIME OC
MULTIPLIER:
1.00
Range: 0.00 to 100.00 in steps of 0.01
MESSAGE
W1 PHASE TIME OC
RESET: Linear
Range: Instantaneous, Linear
MESSAGE
W1 PHASE TIME OC
BLOCK: Disabled
Range: Logc Inpt 1 to 16, Virt Inpt 1 to
16, Output Rly 2 to 8, SelfTest
Rly, Vir Outpt 1 to 5, Disabled
MESSAGE
W1 HARMONIC DERATING
CORRECTION: Disabled
Range: Logic Input 1 to 16, Disabled
Summary of Contents for Multilin 745
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