Technical Data
4.16 Backup Time Overcurrent Protection
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
615
Overcurrent Stages
Inverse Time Stages (IEC)
Pickup value I
Ph
> (phases) for I
N
= 1 A 0.10 A to 25.00 A
or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.50 A to 125.00 A
or ∞ (ineffective)
Pickup value 3I
0
> (earth) for I
N
= 1 A 0.05 A to 25.00 A
or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.25 A to 125.00 A
or ∞ (ineffective)
Delay T
IPh
> (phases) 0.00 s to 30.00 s
or ∞ (ineffective)
Increments 0.01 s
Delay T
3I0
> (earth) 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 times (fast relays/high-speed relays) Approx. 25 ms/20 ms
Dropout times Approx. 30 ms
Tolerances Currents 3 % of setting value or 1 % nominal current
Times 1 % of setting value or 10 ms
The set times are pure delay times
Pickup value I
P
(phases) for I
N
= 1 A 0.10 A to 4.00 A
or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.50 A to 20.00 A
or ∞ (ineffective)
Pickup value 3I
0P
(earth) for I
N
= 1 A 0.05 A to 4.00 A
or ∞ (ineffective)
Increments 0.01 A
for I
N
= 5 A 0.25 A to 20.00 A
or ∞ (ineffective)
Time multipliers T
IP
(phases) 0.05 s to 3.00 s
or ∞ (ineffective)
Increments 0.01 s
T
3I0P
(earth) 0.05 s to 3.00 s
or ∞ (ineffective)
Increments 0.01 s
Additional time delays T
IP delayed
(phases) 0.00 s to 30.00 s Increments 0.01 s
T
3I0P delayed
(earth) 0.00 s to 30.00 s Increments 0.01 s
Characteristics See Figure 4-2
Tolerances
Pickup/dropout thresholds I
p
, 3I
0p
3 % of set value, or 1 % nominal current
Pickup time for 2 ≤ I/3I
0P
≤ 20 and T
IP
≥ 1 s
Pickup time for 2 ≤ I/3I
0P
≤ 20 and T
3I0P
≥ 1 s
5 % of set value ± 15 ms
5 % of set value ± 15 ms
Defined times 1 % of setting value or 10 ms