5–76 850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
SYSTEM CHAPTER 5: DEVICE, SYSTEM, INPUT AND OUTPUT SETPOINTS
FlexCurves
The relay incorporates four programmable FlexCurves - FlexCurve A, B, C and D. The points
for these curves are defined in the EnerVista 8 Series Setup software. User-defined curves
can be used for Time Overcurrent protection in the same way as IEEE, IAC, ANSI, and IEC
curves. Each of the four FlexCurves has 120-point settings for entering times to reset and
operate, 40 points for reset (from 0 to 0.98 times the Pickup value) and 80 for operate (from
1.03 to 20 times the Pickup). This data is converted into two continuous curves by linear
interpolation between data points.
Path: Setpoints > System > FlexCurves
NOTE:
Use the EnerVista 8 Series Setup software program to select, design or modify any of the
FlexCurves.
The following table for FlexCurves A, B, C, and D details the 120 points as well as the
characteristic for each of them, and a blank cell to write the time value when the operation
(for I > I
pickup
) or the reset (for I < I
pickup
) is required.
To Next Page
Loading...
