Technical Data
4.9 Earth Fault Protection in Earthed Systems (optional)
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
599
Overcurrent stage
Inverse Current Stage (IEC)
Pickup value 3I
0
>for I
N
= 1 A 0.05 A to 25.00 A
or
0.003 A to 25.000 A
Increments 0.01 A
Increments 0.001 A
for I
N
= 5 A 0.25 A to 125.00 A
or
0.015 A to 125.000 A
Increments 0.01 A
Increments 0.001 A
Delay T
3I0>
0.00 s to 30.00 s
or ∞ (ineffective)
Increments 0.01 s
Dropout ratio Approx. 0.95 for I/I
N
≥ 0.5
Pickup time (fast relays/high-speed relays)
(1.5 set value)
(2.5 set value)
Approx. 40 ms/35 ms
Approx. 30ms/25 ms
Dropout time Approx. 30 ms
Tolerances Current 3 % of setting value or 1 % nominal current
Time 1 % of setting value or 10 ms
The set times are pure delay times with definite time protection.
Pickup value 3I
0P
for I
N
= 1 A 0.05 A to 25.00 A
or
0.003 A to 25.000 A
Increments 0.01 A
Increments 0.001 A
for I
N
= 5 A 0.25 A to 125.00 A
or
0.015 A to 125.000 A
Increments 0.01 A
Increments 0.001 A
Time factor T
3I0P
0.05 s to 3.00 s
or ∞ (ineffective)
Increments 0.01 s
Additional time delay T
3I0P add
0.00 s to 30.00 s
or ∞ (ineffective)
Increments 0.01 s
Characteristics See Figure 4-2
Tolerances
Pickup and dropout thresholds 3I
0p
3 % of setting value, or 1 % nominal current
Pickup time for 2 ≤ I/3I
0P
≤ 20 and T
3I0P
≥ 1 s 5 % of set value ± 15 ms
Defined times 1 % of set value or 10 ms