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CHAPTER 1: INTRODUCTION
NOTE:
NOTE
339 MOTOR PROTECTION SYSTEM – INSTRUCTION MANUAL
NEUTRAL INSTANTANEOUS OVERCURRENT (50N)
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
Time Delay:............................................................ 0.00 to 300.00 sec in steps of 0.01
Operate Time:....................................................... <30 ms @ 60Hz (I > 2.0 x PKP), 0 ms time delay
Time Delay Accuracy: ...................................... 1% to 1 cycle, whichever is greater
Level Accuracy:.................................................... per CT input
Elements: ................................................................ Trip or Alarm
NEUTRAL DIRECTIONAL OVERCURRENT (67N)
Directionality: ....................................................... Co-existing forward and reverse
Polarizing: ............................................................... Voltage, Current, Dual
Polarizing Voltage:.............................................. -V
Polarizing Current: .............................................. I
MTA:........................................................................... From 0
Angle Accuracy: ..................................................±4
Operation Delay: ................................................. 20 to 30 ms
The selection of "P" option from "339 OTHER OPTIONS" in the Order Code table, will enable
the Neutral Directional element with voltage polarizing V
phase voltage inputs.
UNDERCURRENT (37)
Pickup Level:.......................................................... 0.1 to 0.95 x FLA in steps of 0.01 x FLA
Dropout Level: ...................................................... 102% of Pickup
Time Delay:............................................................ 1.00 to 60.00 s in steps of 0.01 s
Block from Start:.................................................. 0 to 600 s in steps of 1 s
Pickup Accuracy:................................................. as per phase current inputs
Timing Accuracy:................................................±0.5 s or ± 0.5% of total time
Elements: ................................................................ Trip and Alarm
CURRENT UNBALANCE (46)
Unbalance:............................................................. See equations below
Unbalance Pickup Level:.................................. 4.00 to 40.00% in steps of 0.01%
Trip Curves: ............................................................ Definite time, Inverse time (see equations below)
Trip TDM: ................................................................. 1.00 to 100.00 s in steps of 0.01 s
Trip Maximum Time:.......................................... 1.00 to 1000.00 s in steps of 0.01 s
Trip Minimum Time: ........................................... 1.00 to 1000.00 s in steps of 0.01 s
Trip Reset Time: ................................................... 1.00 to 1000.00 s in steps of 0.01 s
Alarm Time Delay:.............................................. 1.00 to 60.00 s in steps of 0.01 s
Single Phasing Pickup Level:.......................... unbalance level > 40% or when I
Single Phasing Time Delay:............................ 2 sec
Dropout Level: ...................................................... Pickup - 1
Pickup Accuracy:................................................. ±2%
Timing Accuracy:................................................±0.5 s or ± 0.5% of total time
Unbalance Elements: ........................................ Trip and Alarm
Single Phasing Elements: ................................ Trip
Pickup - 0.02 x CT @ I <1 x CT
<35 ms @ 50Hz (I > 2.0 x PKP), 0 ms time delay
calculated using phase voltages (VTs must be connected
0
in "Wye")
G
o
o
to 359
in steps of 1
o
computed from the measured
0
in any phase is less than the cutoff current
SPECIFICATIONS
o
≥25%FLA and current
avg
1–9
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