Inverse-Time Overcurrent Protection - Siemens SIPROTEC 4 Manual

4.3

Inverse-time Overcurrent Protection

Operating Modes
Three-phase
Two-phase
voltage-independent,
voltage-controlled,
voltage-dependent
Measuring Method
All elements
Setting Ranges / Increments
Pickup current 51 (phases)
(Phasen)
Pickup current 51N ground
Time multiplier T for 51, 51N for IEC-Kennlinien 0.05 s to 3.20 s or ∞ (disabled)
Time multiplier D for 51, 51N for ANSI-Kennli-
nien
Undervoltage threshold 51V V< for for release
of 51
Trip Time Curves acc. to IEC
Acc. to IEC 60255-151 or BS 142, Section 3.5.2 (see also
The tripping times for Ι/Ι
For zero sequence current, read 3Ι0p instead of Ι
for ground fault, read Ι
Pickup threshold
SIPROTEC 4, 7SJ80, Manual
E50417-G1140-C343-A8, Edition 12.2017
Standard
Phases A and C
First harmonic, rms value (true rms)
for Ι = 1 A 0.10 A to 4.00 A
N
0.50 A to 20.00 A
for Ι = 5 A
N
for Ι = 1 A 0.05 A to 4.00 A
N
for Ι = 5 A 0.25 A to 20.00 A
N
0.50 s to 15.00 s or ∞ (disabled)
10.0 V to 125.0 V
≥ 20 are identical with those for Ι/Ι
p
p
instead of Ι and T instead of T
Ep p
ΙEp
4.3 Inverse-time Overcurrent Protection
Figure 4-1 and Figure
= 20
p
and T instead of T
3Ι0p p
p
approx. 1.10 · Ι
Technical Data
Increments
0.01 A
Increments
0.01 A
Increments
0.01 s
Increments
0.01 s
Increments 0.1V
4-2)
p
365