Inverse Time Overcurrent Protection 51, 51N - Siemens siprotec SJ62 User Manual

4 Technical Data
4.3

Inverse Time Overcurrent Protection 51, 51N

Operating Modes
Setting Ranges / Increments
Trip Time Curves acc. to IEC
461
Three-phase
Two-phase
Pickup current 51 (phases)
Pickup current 51N
Time multipliers T for 51, 51N
IEC curves
Time multipliers D for 51, 51N
ANSI curves
Acc. to IEC 60255-3 or BS 142, Section 3.5.2 (see also Figure 4-1 and 4-2)
The tripping times for I/I
p
For zero-sequence current read 3I0p instead of I
for ground fault read I instead of I
Ep
Pickup Threshold
Standard
Phases A and C
for I = 1 A 0.10 A to 4.00 A
Nom
for I = 5 A 0.50 A to 20.00 A
Nom
for I = 1 A 0.05 A to 4.00 A
Nom
for I = 5 A 0.25 A to 20.00 A
Nom
≥ 20 are identical with those for I/I
and T
p
and T instead of T
p IEp
0.05 s to 3.20 s or ∞
(disabled)
(disabled)
0.50 s to 15.00 s or ∞
(disabled)
= 20.
p
instead of T ;
3I0p p
p
approx. 1.10 · I
p
SIPROTEC 4, 7SJ62/63/64 Handbuch
C53000-G1140-C147-A, Edition 07.2015
Increments
0.01 A
Increments
0.01 A
Increments
0.01 s
Increments
0.01 s