GE 850 Instruction Manual page 28

SPECIFICATIONS
1–18
FREQUENCY RATE OF CHANGE (81R)
df/dt Trend:............................................................ Increasing, Decreasing, Bi-directional
df/dt Pickup Level:.............................................. 0.10 to 15.00 Hz/s in steps of 0.01 Hz/s
df/dt Dropout Level: .......................................... 96% of Pickup Level
df/dt Level Accuracy:........................................ 80 mHz/s or 3.5%, whichever is greater
Minimum Frequency:........................................ 20.00 to 80.00 Hz in steps of 0.01 Hz
Maximum Frequency: ...................................... 20.00 to 80.00 Hz in steps of 0.01 Hz
Minimum Voltage Threshold: ........................ 0.000 to 1.250 x VT in steps of 0.001 x VT
Minimum Current Threshold: ........................ 0.000 to 30.000 x CT in steps of 0.001 x CT
Pickup Time Delay: ............................................ 0.000 to 6000.000 s in steps of 0.001 s
Timer Accuracy:.................................................. ± 3% of delay setting or ± ¼ cycle (whichever is greater)
95% Settling Time for df/dt: .......................... < 24 cycles
Operate Time: ...................................................... typically 10 cycles at 2 × Pickup
GROUND DIRECTIONAL OVERCURRENT (67G)
Directionality: ....................................................... Co-existing forward and reverse
Polarizing:............................................................... Voltage, Current, Dual
Polarizing Voltage:.............................................. V_0 or VX
Polarizing Current:.............................................. Isg
Operating Current: ............................................. Ig
Level Sensing:....................................................... Ig, Isg
Characteristic Angle:......................................... -90º to 90º in steps of 1°
Limit Angle: ............................................................ 40º to 90º in steps of 1°, independent for forward and
Angle Accuracy: .................................................. ±2º
Pickup Level: ......................................................... 0.050 to 30.000 x CT in steps of 0.001
Dropout Level:...................................................... 97 to 98%
Operate Time (no direction transition): .... < 12 ms typical at 3 x Pickup at 60 Hz
LOAD ENCROACHMENT
Operating Parameter: ...................................... Positive sequence impedance (V1/I1)
Reach (in secondary Ω): .................................. 0.02 to 250.00 Ω in steps of 0.01Ω
Angle:........................................................................ 5º to 50º in steps of 1°
Minimum Voltage: .............................................. 0.00 to 1.50 x VT in steps of 0.01 x VT
Impedance Accuracy: ...................................... ± 5%
Angle Accuracy: .................................................. ± 2º
Pickup Time Delay: ............................................ 0.000 to 6000.000 s in steps of 0.001 s
Dropout Time Delay:......................................... 0.000 to 6000.000 s in steps of 0.001 s
Operate Time: ...................................................... <20 ms at 1.1 x pickup at 60 Hz
Timing Accuracy:................................................ ± 3% of delay setting or ± ¼ cycle (whichever is greater)
from pickup to operate
reverse
< 15 ms typical at 3 x Pickup at 50 Hz
<24 ms at 1.1 x pickup at 50 Hz
from pickup to operate
850 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: INTRODUCTION