GE Multilin 345 - Page 18

1–10 345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
SPECIFICATIONS CHAPTER 1: INTRODUCTION
SENSITIVE GROUND TIMED OVERCURRENT (51SG)
Pickup Level: ......................................................... 0.005 to 3.000 x CT in steps of 0.001 x CT
Dropout Level:...................................................... 97% of Pickup @ I > 0.1 x CT
Pickup - 0.002 x CT @ I < 0.1 x CT
Curve Shape:......................................................... ANSI Extremely/Very/Moderately/Normally Inverse
Definite Time
IEC Curve A/B/C/Short
IAC Extremely/Very/-/Short Inverse
Curve Multiplier: .................................................. 0.05 to 50.00 in steps of 0.1
Reset Time:............................................................ Instantaneous, Linear
Curve Timing Accuracy:.................................. ±3% of expected inverse time or 1 cycle, whichever is
greater, from pickup to operate
Level Accuracy: ................................................... per CT input
PHASE/NEUTRAL/GROUND/NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT
(50P/50N/50G/50_2)
Pickup Level: ......................................................... 0.05 to 20.00 x CT in steps of 0.01 x CT
Dropout Level:...................................................... 97% of Pickup @ I > 1 x CT
Pickup - 0.02 x CT @ I <1 x CT
Time Delay: ........................................................... 0.00 to 300.00 sec in steps of 0.01
Operate Time: ...................................................... <30 ms @ 60Hz (I > 2.0 x PKP, No time delay)
<35 ms @ 50Hz (I > 2.0 x PKP, No time delay)
Time Delay Accuracy:...................................... 1% or 1 cycle, whichever is greater (Time Delay selected)
Level Accuracy: ................................................... per CT input
SENSITIVE GROUND INSTANTANEOUS OVERCURRENT (50SG)
Pickup Level (Gnd IOC):..................................... 0.005 to 3.000 x CT in steps of 0.001 x CT
Dropout Level:...................................................... 97% of Pickup @ I > 0.1 x CT
Pickup - 0.002 x CT @ I < 0.1 x CT
Time Delay: ........................................................... 0.00 to 300.00 sec in steps of 0.01
Operate Time: ...................................................... <30 ms @ 60Hz (I > 2.0 x PKP, No time delay)
<35 ms @ 50Hz (I > 2.0 x PKP, No time delay)
Time Delay Accuracy:...................................... 1% or 1 cycle, whichever is greater (Time Delay selected)
Level Accuracy: ................................................... per CT input
TRANSFORMER THERMAL PROTECTION (49)
Current:.................................................................... RMS current - max (Ia, Ib, Ic)
Pickup Accuracy: ................................................ per current inputs
Timing Accuracy:................................................ ±3% of expected time, or 30 ms (whichever is greater)
@ I > 1.5 x PKP
TRANSFORMER PERCENT DIFFERENTIAL PROTECTION (87T)
Differential/Restraint Characteristic:......... Dual Slope, Dual Breakpoint
Minimum Pickup Level: .................................... 0.05 to 1.00 x CT in steps of 0.01
Slope 1 Range: ..................................................... 15 to 100% in steps of 1%
Slope 2 Range: ..................................................... 50 to 100% in steps of 1%
Kneepoint 1:.......................................................... 0.50 to 4.00 x CT in steps of 0.01
Kneepoint 2:.......................................................... 1.00 to 10.00 x CT in steps of 0.01
2
nd
Harmonic Inhibit Level:............................ 1.0 to 40.0% insteps of 0.1%
2
nd
Harmonic Inhibit Mode:........................... Per-phase, 2-out-of-3, Average, 1-out-of-3
5
th
Harmonic Inhibit Level:............................. 1.0 to 40.0% insteps of 0.1%
Dropout Level:...................................................... 95% of Pickup
Operate Time: ...................................................... < 20 ms (no harmonics inhibits selected)
< 30 ms (harmonics inhibits selected)
Level Accuracy: ................................................... per current inputs
TRANSFORMER INSTANTANEOUS DIFFERENTIAL PROTECTION (50/87)
Pickup Level: ......................................................... 3.00 to 20.00xCT in steps of 0.01xCT
Dropout Level:...................................................... 95% of Pickup
Operate Time: ...................................................... <30 ms
Level Accuracy: ................................................... per current inputs