1–8
350 FEEDER PROTECTION SYSTEM – INSTRUCTION MANUAL
SPECIFICATIONS
CHAPTER 1: INTRODUCTION
SENSITIVE GROUND INSTANTANEOUS OVERCURRENT (50SG)
Pickup Level (Gnd IOC):.....................................0.005 to 3 x CT in steps of 0.001 x CT
Dropout Level:......................................................97 to 99% 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:.......................................0 to 1 cycle (Time Delay selected)
Level Accuracy:....................................................per CT input
GROUND DIRECTIONAL
Directionality:........................................................Co-existing forward and reverse
Operating: ..............................................................Ground Current (Ig)
Polarizing Voltage:..............................................-V
0
calculated using phase voltages (VTs must be connected
in “Wye”)
- V
0
measured from Vaux input. (3V
0
provided by an external
open delta connection).
MTA:...........................................................................From 0
º
to 359
º
in steps of 1°
Angle Accuracy:...................................................±4
º
Operational Delay: .............................................20 to 30 ms
NOTE
NOTE:
The selection of the “P” or “R” option from “350 OTHER OPTIONS” in the order code table,
will enable the Ground directional element. The polarizing voltage used for this element is
the computed V
0
from the measured phase voltage inputs.
NEUTRAL DIRECTIONAL
Directionality:........................................................Forward and reverse
Polarizing:...............................................................Voltage, Current, Dual
Polarizing Voltage:..............................................- V
0
calculated using phase voltages (VTs must be
connected in “Wye”)
- V
0
measured by Vaux input (3V
0
provided by an external
open delta connection).
Polarizing Current:..............................................I
G
MTA:...........................................................................From 0
º
to 359
º
in steps of 1°
Angle Accuracy:...................................................±4
º
Operational Delay: .............................................20 to 30 ms
NOTE
NOTE:
The selection of the “P” or “R” option from “350 OTHER OPTIONS” in the order code table will
enable the Neutral directional element. The polarizing voltage used for this element is the
computed V
0
from the measured phase voltage inputs. The ground polarizing current, I
G
, is
also available for selection.
CABLE THERMAL MODEL (49)
Current:....................................................................Fundamental phasor
Pickup Accuracy:.................................................per current inputs
Timing Accuracy:................................................See graph below
