Schweitzer Engineering SEL-351P, Quick Start Manual

Page: 179 / 674

Date Code 990430 Overcurrent, Voltage, Synchronism Check, and Frequency Elements 3-11
SEL-351P Manual Técnico
Figure SECTION 3: .9: Levels 5 through 6 Neutral Ground Instantaneous
Overcurrent Elements
Settings Ranges
Setting range for pickup settings 50N1P through 50N6P:
0.005 - 1.500 A secondary (0.05 A nominal channel IN current input)
Setting range for definite-time settings 67N1D through 67N4D:
0.00 - 16000.00 cycles, in 0.25-cycle steps
Setting range for definite-time setting 67N2SD (used in DCB logic):
0.00 - 60.00 cycles, in 0.25-cycle steps
Note: Because channel IN is rated 0.05 A nominal, there is an additional 2-cycle time delay on
all the neutral ground instantaneous (50N1 - 50N6, 67N1 - 67N6) and definite-time
(67N1T - 67N4T) elements. Any time delay provided by the definite-time settings
(67N1D - 67N4D) is in addition to this 2-cycle time delay.
Accuracy
Pickup:
±
1 mA secondary and
±
5% of setting (0.05 A nominal channel IN current input)
Timer:
±
0.25 cycles and
±
0.1% of setting
Transient Overreach:
±
5% of setting
Pickup and Reset Time Curves
See Figure SECTION 3: .5 and Figure SECTION 3: .6.