GE 745 Instruction Manual page 135

CHAPTER 5: SETPOINTS
5.4.7 Voltage Input

VOLTAGE INPUT [
5.4.8 Ambient Temperature

AMBIENT TEMP [
745 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
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.
PATH: SETPOINTS S2 SYSTEM SETUP


] VOLTAGE SENSING:
Disabled
VOLTAGE INPUT
MESSAGE
PARAMETER: W1 Van
NOMINAL VT SECONDARY
MESSAGE
VOLTAGE: 120.0 V
VT RATIO:
MESSAGE
1000:1
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.
PATH: SETPOINTS S2 SYSTEM SETUP


] AMBIENT TEMPERATURE
SENSING: Disabled
AMBIENT RTD TYPE:
MESSAGE
100 Ω Platinum
AVERAGE AMBIENT TEMP
MESSAGE
FOR JANUARY: 20°C
AVERAGE AMBIENT TEMP
MESSAGE
FOR DECEMBER: 20°C
• AMBIENT RTD SENSING: Select "Enabled" to use an RTD to monitor ambient
temperature.
VOLTAGE INPUT

Range:
Range:
Range:
Range:
AMBIENT TEMP

Range:
Range:
Range:
↓
Range:
S2 SYSTEM SETUP
Enabled, Disabled
W1, W2, W3;
Van, Vbn, Vcn, Vab, Vbc, Vca
60.0 to 120.0 in steps of 0.1
1 to 5000:1 in steps of 1
Enabled, Disabled
100 Ω Platinum, 120 Ω Nickel,
100 Ω Nickel, By Monthly
Average
–50 to 125°C in steps of 1
–50 to 125°C in steps of 1
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