Siemens SIPROTEC 4, User Manual

Page: 452 / 734

Inverse-time Overcurrent Protection
Operating Modes
Three-phase Standard
Two-phase Phases A and C
voltage-independent,
voltage-controlled,
voltage-dependent
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
Undervoltage threshold
51V V<
for for release
of 51
10.0 V to 125.0 V Increments 0.1V
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 3
Ι
0p instead of
Ι
p
and T
3
Ι
0p
instead of T
p
for ground fault, read
Ι
Ep
instead of
Ι
p
and T
Ι
Ep
instead of T
p
Pickup threshold
approx. 1.10 ·
Ι
p
4.3
Technical Data
4.3 Inverse-time Overcurrent Protection
452 SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016