Flexcurves - GE 845 Instruction Manual

CHAPTER 4: SETPOINTS

FlexCurves

NOTE:
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
The relay incorporates four programmable FlexCurves - FlexCurve A, B, C and D. The points
for these curves are defined by the user in the EnerVista program. 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
Please use the EnerVista 8 Series Setup software program to select, design or modify any
of the four FlexCurves.
The following table details the 120 points as well as the characteristic for each of them,
and a blank cell where the user can write the time value when the operation (for I > I
or the reset (for I < I ) is required.
pickup
SYSTEM
)
pickup
4–115