GE 845 Instruction Manual page 20

SPECIFICATIONS
NOTE:
NOTE
1–12
Operating time specifications given above are applicable when RMS inputs are used.
Typical times are average operate times over multiple test cases.
Timer Accuracy: .................................................. ±3% of delay setting or ± ¼ cycle (whichever is greater) from
NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT (50_2)
Current:.................................................................... I_2 Fundamental Phasor Magnitude
Pickup Level: ......................................................... 0.050 to 30.000 x CT in steps of 0.001 x CT
Dropout Level:...................................................... 97 to 98% of Pickup
Level Accuracy:.................................................... For 0.1 to 2.0 x CT: ±0.5% of reading or ± 0.4% of rated,
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
Overreach: ............................................................. < 2%
Operate Time: ...................................................... < 12 ms typical at 3 x Pickup at 60 Hz
Timer Accuracy: .................................................. ±3% of delay setting or ± ¼ cycle (whichever is greater) from
PHASE DIRECTIONAL OVERCURRENT (67P)
Relay Connection:............................................... 90º(Quadrature)
Quadrature Voltage:.......................................... ABC phase seq.: phase A (Vbc), phase B (Vca), phase C (Vab);
Polarizing Voltage Threshold:........................ 0.050 to 3.000 x VT in steps of 0.001 x VT
Current Sensitivity Threshold: ....................... 0.05 x CT
Characteristic Angle:......................................... 0º to 359º in steps of 1°
Angle Accuracy:................................................... ± 2º
Operation Time (FlexLogic™ operands):.. Reverse to Forward transition: < 12 ms, typically;
NEUTRAL DIRECTIONAL OVERCURRENT (67N)
Directionality:........................................................ Co-existing forward and reverse
Polarizing:............................................................... Voltage, Current, Dual
Polarizing Voltage:.............................................. V_0 or VX
Polarizing Current:.............................................. Ig
Operating Current: ............................................. I_0
Level Sensing:....................................................... 3 x (|I_0| – K x |I_1|), Ig
Restraint, K: ........................................................... 0.000 to 0.500 in steps of 0.001
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 x CT
Dropout Level:...................................................... 97 to 98% of Pickup
Operate Time (no direction transition): .... < 16 ms at 3 x Pickup at 60 Hz
pickup to operate
whichever is greater
For > 2.0 x CT: ± 1.5% of reading
< 15 ms typical at 3 x Pickup at 50 Hz
pickup to operate
ACB phase seq.: phase A (Vcb), phase B (Vac), phase C (Vba)
Forward to Reverse transition: <8 ms, typically
reverse
< 20 ms at 3 x Pickup at 50 Hz
845 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
CHAPTER 1: INTRODUCTION