Ormazabal ekor.rps, General Instructions Manual

Page: 72 / 144

IG-150-EN version 04; 03/10/16
72
Protection functions. Description and settings General instructions
ekor.rps
4.7. Sensitive neutral overcurrent protection
4.7.1. General description
Sensitive neutral overcurrent protection, with the same
possible characteristics as the ones described for phases
(except that there is only one instantaneous element), and
independent settings (function 50Ns/51Ns).
4.7.2. Setting ranges of the timed characteristic (6 tables) (normal and HIGH2)
Setting Min Max Step Notes
Enable YES/NO/pickup/YES+drop
Pickup [A]
0.0005 1.0000 0.0001 With standard ratings
0.005 10,000 0.001 With specified ratings
Curve type
Definite time
Normal inverse curve, very inverse curve,
extremely inverse curve
User curve
Time index
0.05
0.5
1.09
30.0 0.01
0.1
For IEC curves
For ANSI curves
Definite time [s]
0.0 1,800.0 0.01
These settings can be found in the console on the screen “overcurrent protection (1)”
Table 4.10. Setting ranges of the timed characteristic
The remarks about curves and accuracy in times are the
same as the ones quoted for phases.
4.7.3. Setting ranges of the instantaneous characteristic (single level) (6 tables) (normal and HIGH2)
Setting Min Max Step Notes
Enable
YES/NO/pick up
Sensitive neutral instant. trip [A]
0.0005 1,0000 0.0001
With standard ratings
0.005 10.0 0.001 With specified ratings
Additional time [s]
0.00 600.00 0.01
Special operation
See “instant. special operation”
These settings can be found in the console on the screen “overcurrent protection (1)”
Table 4.11. Setting ranges of the instantaneous characteristic
The tripping current is set to secondary amps. The remarks about operating times are the same as the
ones quoted for phases.