GE 845 Instruction Manual page 309

CHAPTER 4: SETPOINTS
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
PICKUP
Range: 0.00 to 1.50 x VT in steps of 0.01 x VT
Default: 1.00 x VT
This setting sets the Phase Undervoltage Pickup level specified per times VT.
For example, a Pickup setting of 0.80 x VT with a 13800:115 VT translates into 11.04kV (or
92V secondary). If the mode selection is phase to phase and the Setpoints/System
Setup/Voltage Sensing/Phase VT Connection selection is Wye, the previous example
translates to the phase to phase voltage value of 11.04kV x 1.732 = 19.12kV.
MINIMUM VOLTAGE
Range: 0.00 to 1.50 x VT in steps of 0.01 x VT
Default: 0.20 x VT
This setting sets the minimum operating voltage for the undervoltage Pickup level
specified per times VT.
For example, a PKP setting of 0.20 x VT with 13800:115 VT translates into 2.76kV (or 23V
secondary).
If the mode selection is Phase to phase and Setpoints/System Setup/Voltage Sensing/
Phase VT Connection selection is Wye, the previous example translates to the phase to
phase voltage value of 2.76kV x 1.732 = 4.78kV.
PHASES FOR OPERATION
Range: Any One, Any Two, All Three
Default: Any One
This setting defines the number of voltages required for operation of the Phase UV
protection function.
UNDERVOLTAGE CURVES
Range: Definite Time, Inverse Time
Default: Definite Time
This setting provides the selection of definite time delay or time delay inverse
undervoltage curves.
PICKUP DELAY
Range: 0.000 to 6000.000 s in steps of 0.001 s
Default: 1.000 s
If Inverse Time is selected as an Undervoltage Curve setpoint, the Pickup Delay value is
loaded to variable D in the curve formula. For more information, refer to
Curves on page 4-203.
BLOCK
Range: Off, Any operand from the list of FlexLogic operands
Default: Off
RELAYS
Range: Do Not Operate, Operate
Default: Do Not Operate
EVENTS
Range: Enabled, Disabled
Default: Enabled
TARGETS
Range: Disabled, Self-reset, Latched
Default: Self-reset
PROTECTION
Undervoltage
4–205