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Dropout Time Characteristics with Disk Emulation acc. to IEC
Acc. 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/Ip) ≤ 0.90
For zero sequence current, read 3I0p instead of I
for ground fault, read I
Dropout Setting
IEC without Disk Emulation
IEC with Disk Emulation
Tolerances
Pickup/dropout thresholds I
Trip time for 2 ≤ I/I
Dropout time for I/Ip ≤ 0.90
Influencing Variables for Pickup and Dropout
Power supply direct voltage in range 0.8 ≤ V
Temperature in Range 23.00 °F (–5 °C) ≤ Θ
Frequency in range of 25 Hz – 70 Hz
Frequency in range of 0.95 ≤ f/f
Frequency in Range 0.95 ≤ f/f
Harmonics
- up to 10 % 3rd harmonic
- up to 10 % 5th harmonic
Transient overreaction during first harmonic measuring technique for τ > 100 ms (with full
displacement)
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
instead of I
and T
Ep
p
approx. 1.05 · setting value I
0.95 · pickup value
approx. 0.90 · I
, I
3 % of setting value or 15 mA for I
p
Ep
≤ 20
5 % of reference (calculated) value +2 % current tolerance, or 30 ms
p
5 % of reference (calculated) value +2 % current tolerance, or 30 ms
≤ 1.05 (f
Nom
≤ 1.05
Nom
and T
instead of T
p
3I0p
instead of T
p
IEp
for I
p
setting value
p
≤ 1.15
/V
Aux
AuxNom
≤ 131.00 °F (55 °C)
amb
= 50 Hz or 60 Hz)
Nom
Technical Data
4.3 Inverse-time Overcurrent Protection
;
p
≥ 0.3, this corresponds to approx.
/I
p
N
= 1 A, or 75 mA for I
Nom
1 %
0.5 %/10 K
1 %
Increased Toler-
ances
1 %
1 %
<5 %
= 5 A
Nom
363
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