Siemens SIPROTEC 4 7SJ61 - Inverse-time Overcurrent Protection

Inverse-time Overcurrent Protection
Operating Modes
Three-phase Standard
Two-phase Phases A and C
Measuring Method
All elements First harmonic, rms value (true rms)
Setting Ranges / Increments
Pickup current 51 (phases)
(Phasen)
for Ι
N
= 1 A
0.10 A to 4.00 A Increments
0.01 A
for Ι
N
= 5 A
0.50 A to 20.00 A
Pickup current 51N ground
for Ι
N
= 1 A
0.05 A to 4.00 A Increments
0.01 A
for Ι
N
= 5 A
0.25 A to 20.00 A
Time multiplier T for 51, 51N for IEC-Kennlinien 0.05 s to 3.20 s or ∞ (disabled) Increments
0.01 s
Time multiplier D for 51, 51N for ANSI-Kennli-
nien
0.50 s to 15.00 s or ∞ (disabled) Increments
0.01 s
Trip Time Curves acc. to IEC
Acc. to IEC 60255-3 or BS 142, Section 3.5.2 (see also
Figure 4-1 and Figure 4-2)
The tripping times for Ι/Ι
p
≥ 20 are identical with those for Ι/Ι
p
= 20
For zero sequence current, read 3Ι0p instead of Ι
p
and T
3Ι0p
instead of T
p
for ground fault, read Ι
Ep
instead of Ι
p
and T
ΙEp
instead of T
p
Pickup threshold
approx. 1.10 · Ι
p
4.3
Technical Data
4.3 Inverse-time Overcurrent Protection
292 SIPROTEC 4, 7SJ61, Manual
C53000-G1140-C210-6, Edition 05.2016