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5 SETPOINTS
ENERGIZATION SENSING
BY VOLTAGE: Disabled
MINIMUM ENERGIZATION
VOLTAGE: 0.85 X VT
BREAKERS ARE OPEN
SIGNAL: Disabled
PARALL XFMR BRKR CLS
SIGNAL: Disabled
e) 5TH HARMONIC INHIBIT
This section contains the settings of the 5
allows inhibiting the percent differential during intentional overexcitation of the system. This feature inhibits the
percent differential element in a particular phase if the 5
inhibit level setting. With harmonic averaging enabled, all three phases are inhibited if the three-phase average
th
of the 5
harmonic exceeds the level setting.
S 5th HARM INHIBIT
S [ENTER] for more
5th HARMONIC INHIBIT
FUNCTION: Disabled
HARMONIC AVERAGING:
Disabled
5th HARMONIC INHIBIT
LEVEL: 10.0% ƒο
GE Power Management
Range: Disabled / Enabled
Select Enabled to detect de-energization by the level of the voltage dropping
below the minimum energization voltage. This setpoint is displayed only if
voltage sensing is enabled under S2 SYSTEM SETUP/VOLTAGE INPUT.
Range: 0.50 to 0.99 (steps of 0.01)
Enter the voltage level below which the transformer is considered de-
energized (when ENERGIZATION SENSING BY VOLTAGE is Enabled). Displayed
only if S2 SYSTEM SETUP/VOLTAGE INPUT/VOLTAGE SENSING is Enabled .
Range: Disabled / Logc Inpt 1 (2-16)
Select any logic input which, when asserted, will indicate to the 745 that the
transformer is de-energized. The selected logic input should be connected to
the auxiliary contacts of the transformer breaker or disconnect switch.
Range: Disabled / Logc Inpt 1 (2-16)
Select any logic input which, when asserted, will indicate to the 745 the
onset of sympathetic inrush. The selected logic input should be connected to
the close command going to the parallel transformer switching device.
th
harmonic inhibit feature of the percent differential element, which
th
harmonic of the same phase exceeds the harmonic
This message indicates the start of the 5TH HARMONIC INHIBIT section. To
continue with these setpoints press
next section.
Range: Disabled / Enabled
Range: Disabled / Enabled
Select 'Enabled' to use the three-phase average of the 5th harmonic current
against the harmonic inhibit setting.
Range: 0.1 to 65.0 (steps of 0.1)
Enter the level of 5th harmonic current above which the percent differential
element will be inhibited from operating.
745 Transformer Management Relay
5.6 S4 ELEMENTS
, or press
to go to the
E N TE R
M E SSA G E
5
5-51
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