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S2 System Setup
745
Transformer Management Relay
Se
tpoints
http://www.GEindustrial.com/multilin
5–34
GE Multilin
information that is often only available from the transformer manufacturer’s test
report, including the three-phase resistance of each winding and the load loss at
rated load. The harmonic derating factor will only be valid if this information has
been entered correctly.
The 745 also calculates the total harmonic distortion of the phase current input
signals. The band of frequencies over which this calculation is made can be changed
to be more selective than the default 2
nd
to 21
st
harmonics.
•
HARMONIC DERATING FUNCTION
: Enter “Enabled” to enable the harmonic
derating factor calculations.
•
THD MINIMUM/MAXIMUM HARMONIC NUMBER
Enter the minimum/
maximum harmonic number of the frequency band over which total harmonic
distortion is calculated.
FlexCurves™
PATH: SETPOINTS
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S2 SYSTEM SETUP
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FLEXCURVES
!
FLEXCURVE A(C)
Three programmed custom FlexCurves™ can be stored in the 745 as FlexCurve™ A,
FlexCurve™ B, and FlexCurve™ C. This allows the user to save special curves for
specific applications and then select them as required for time overcurrent element
curves. The custom FlexCurve™ has setpoints for entering the times-to-trip at
various levels of pickup. The levels are as follows: 1.03, 1.05, 1.1 to 6.0
×
PU in
steps of 0.1, and 6.5 to 20.0
×
PU in steps of 0.5.
•
FLEXCURVE A DELAY AT
n
×
PU
: Enter the trip time for
n
= 1.03. 1.05,...,
20.0
×
PU for FlexCurve™ A(C). The messages that follow sequentially
correspond to the trip times for the various pickup levels as indicated above.
Voltage Input
PATH: SETPOINTS
!"
S2 SYSTEM SETUP
!"
VOLTAGE INPUT
The 745 provides a voltage input for the purposes of energization detection (for the
Energization Inhibit feature of the percent differential element), overexcitation
protection (the Volts-per-Hertz 1 and 2 functions), and frequency protection (the
Underfrequency, Frequency Decay, and Overfrequency functions). Note that the
frequency elements will use the Winding 1 Phase A current input if voltage is not
available.
•
VOLTAGE INPUT PARAMETER
: Enter the winding and phase of the voltage
connected to the voltage input.
•
NOMINAL VT SECONDARY VOLTAGE
: Enter the nominal secondary voltage
(in volts) of the voltage transformer.
•
VT RATIO
: Enter the ratio of the voltage transformer.
!
FLEXCURVE A
[
!
]
FLEXCURVE A DELAY AT
1.03 x PU:
0 ms
Range: 0 to 65000 ms in steps of 1
MESSAGE
FLEXCURVE A DELAY AT
1.05 x pu:
0 ms
Range: 0 to 65000 ms in steps of 1
↓
MESSAGE
FLEXCURVE A DELAY AT
20.0 x pu:
0 ms
Range: 0 to 65000 ms in steps of 1
!
VOLTAGE INPUT
[
!
]
VOLTAGE SENSING:
Disabled
Range: Enabled, Disabled
MESSAGE
VOLTAGE INPUT
PARAMETER: W1 Van
Range: W1, W2, W3;
Van, Vbn, Vcn, Vab, Vbc, Vca
MESSAGE
NOMINAL VT SECONDARY
VOLTAGE: 120.0 V
Range: 60.0 to 120.0 in steps of 0.1
MESSAGE
VT RATIO:
1000:1
Range: 1 to 5000:1 in steps of 1
Summary of Contents for Multilin 745
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