GE 889 Instruction Manual page 293

CHAPTER 4: SETPOINTS
889 GENERATOR PROTECTION SYSTEM – INSTRUCTION MANUAL
The custom FlexCurves are described in detail in the FlexCurves section of this chapter. The
curve shapes for the FlexCurves are derived from the formulae:
Where:
T = operate time (in seconds),
TDM = Multiplier setting,
I = input current,
I = Pickup Current setting,
pickup
T = reset time in seconds (assuming energy capacity is 100% and RESET is
RESET
"Timed")
DEFINITE TIME CURVES
The Definite Time curve shape operates as soon as the Pickup level is exceeded for a
specified period of time. The base Definite Time curve delay is in seconds. The curve
multiplier of 0.05 to 600 makes this delay adjustable from 50 to 600000 milliseconds.
Where:
T = operate time (in seconds)
TDM = Multiplier setting
I = input current
I = Pickup Current setting
pickup
T = reset time in seconds (assuming energy capacity is 100% and RESET is
RESET
"Timed")
PROTECTION
4–163