Line - GE 750 Instruction Manual

CHAPTER 5: SETPOINTS
5.3.3 Line VT Sensing

LINE VT
SENSING
5.3.4 Power System

POWER SYSTEM
750 FEEDER MANAGEMENT RELAY – INSTRUCTION MANUAL
• NOMINAL VT SECONDARY VOLTAGE: This setpoint represents the voltage across the
VT secondary winding when nominal voltage is applied to the primary. On a source of
13.8 kV line-line at nominal voltage, with a 14400:120 V VT in the Delta connection, the
voltage to be entered is "115 V". For the Wye connection, the voltage to be entered is
115 / = 66.4 V.
3
• VT RATIO: Enter the VT primary to secondary turns ratio with this setpoint. For a
14400:120 VT, the entry would be "120:1" (since 14400 / 120 = 120.0).

PATH: SETPOINTS S2 SYSTEM SETUP
[]
MESSAGE
MESSAGE
With a Line VT installed, the relay can be used to check for a condition of synchronism
between two voltages, either line-line or line-neutral.
• VT CONNECTION: Enter the Line VT connection made to the system. This selection is
critical to the operation of synchrocheck, as it instructs the relay which Bus VT input
voltage is to be compared to the Line VT input voltage. See FIGURE 3–13: Line VT
Connections on page 3–14 for the system connection to match this setpoint.
• NOMINAL VT SECONDARY VOLTAGE: This setpoint represents the voltage across the
VT secondary winding when nominal voltage is applied to the primary. On a source of
13.8 kV line-line at nominal voltage, with a 14400:120 V VT in the Delta connection, the
voltage to be entered is 115 V. For the Wye connection, the voltage to be entered is
115 / = 66.4 V.
3
• VT RATIO: Enter the VT primary to secondary turns ratio with this setpoint. For a
14400:120 VT, the entry would be "120:1" (since 14400 / 120 = 120.0).

PATH: SETPOINTS S2 SYSTEM SETUP
[]
MESSAGE
MESSAGE
The power system data is entered in this setpoint subgroup.

LINE VT SENSING
VT CONNECTION TYPE:
Vbn
NOMINAL VT SECONDARY
VOLTAGE: 120.0 V
VT RATIO:
120.0:1

POWER SYSTEM
NOMINAL FREQ:
60 Hz
PHASE SEQUENCE:
ABC
COST OF ENERGY:
5.0 ¢/kWh
S2 SYSTEM SETUP
Range: Van, Vbn, Vcn, Vab,
Vcb
Range: 50.0 to 240.0 V in
steps of 0.1
Range: 1.0 to 5000.0 in steps
of 0.1
Range: 25 to 60 Hz in steps
of 1
Range: ABC, ACB
Range: 1.0 to 25.0 ¢/kWh in
steps of 0.1
5 - 23