CHAPTER 5: SETPOINTS S4 ELEMENTS
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL 5–55
setpoint is displayed only if S2 SYSTEM SETUP VOLTAGE INPUT VOLTAGE SENSING
is “Enabled”.
• MINIMUM ENERGIZATION VOLTAGE: Enter the voltage level below which the
transformer is considered de-energized (when
ENERGIZATION SENSING BY VOLTAGE is
“Enabled”). This setpoint is displayed only if
S2 SYSTEM SETUP VOLTAGE INPUT
VOLTAGE SENSING
is “Enabled”.
• BREAKERS ARE OPEN SIGNAL: Select any logic input which, when asserted, indicates
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.
• PARALL XFMR BRKR CLS SIGNAL: 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.
FIGURE 5–11: Energization inhibit scheme logic
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