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Technical Data
4.3 Inverse-Time Overcurrent Protection 51(N)
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008
482
Dropout Time Characteristics with Disk Emulation acc. to IEC
Dropout Setting
Tolerances
Influencing Variables for Pickup and Dropout
Ass. to IEC 60255-3 or BS 142, Section 3.5.2 (see also Figures 4-1 and 4-2)
The dropout time curves apply to (
I
/
I
p)
≤
0.90
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
IEC without Disk Emulation
approx. 1.05 · setting value
I
p
for
I
p
/
I
N
≥
0.3, this corresponds to approx.
0.95 · pickup value
IEC with Disk Emulation
approx. 0.90 · set value
I
p
Pickup/dropout thresholds
I
p
,
I
Ep
2% of setting value or 10 mA for
I
N
= 1 A, or 50 mA for
I
N
= 5 A
Pickup time for 2
≤
I
/
I
p
≤
20
5 % of reference (calculated) value + 2 % current tolerance, respective-
ly 30 ms
Dropout time for
I
/
I
p
≤
0.90
5 % of reference (calculated) value + 2 % current tolerance, respective-
ly 30 ms
Power supply direct voltage in range 0.8
≤
V
PS
/V
PSNom
≤
1.15
1 %
Temperature in range 23.00 °F (-5 °C)
≤
Θ
amb
≤
131.00 °F (55 °C)
0.5 %/10 K
Frequency in range 0.95
≤
f/f
Nom
≤
1.05
1 %
Harmonics
- up to 10 % 3rd harmonic
- up to 10 % 5th harmonic
1 %
1 %
Transient overreaction during fundamental harmonic measuring procedure for
τ
> 100 ms
(with full displacement)
<5 %
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