
Technical Data
4.3 Inverse-Time Overcurrent Protection 51(N)
SIPROTEC, 7SJ61, Manual
C53000-G1140-C210-1, Release date 02.2008
324
Trip Time Curves acc. to ANSI
Acc. to ANSI/IEEE (see also Figures 4-3 to 4-6)
The tripping times for
I
/
I
p
≥
20 are identical with those for
I
/
I
p
= 20.
For zero-sequence current read 3
I
0p instead of
I
p
and T
3
I
0p
instead of T
p
;
for ground fault read
I
Ep
instead of
I
p
and T
I
Ep
instead of T
p
Pickup Threshold
approx. 1.10 ·
I
p