Siemens siprotec 7SA522 - Page 465

4.11 Time Overcurrent Protection
465
7SA522 Manual
C53000-G1176-C155-3
Definite Time Overcurrent Stage
Inverse Time Overcurrent Stage (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
Ph
> (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 Approx. 25 ms
Drop-off 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
Ph
(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 PICKUP
(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 factors T
IP
(phases)
0.05 s to 3.00 s
or ∞ (ineffective)
Increments 0.01 s
T
3I0p Time Dial
(earth)
0.05 s to 3.00 s
or ∞ (ineffective)
Increments 0.01 s
Additional time delays T
IP add T-
Delay
(phases)
0.00 s to 30.00 s Increments 0.01 s
T
3I0p add T-
Delay
(earth)
0.00 s to 30.00 s Increments 0.01 s
Characteristics See Figure 4-1
Tolerances currents Pick-up at 1.05 ≤ I/I
P
≤ 1.15
or 1.05 ≤ I/3I
0P
≤ 1.15
Tolerances times 5 % ± 15 ms for 2 ≤ I/3I
OP
≤ 20 and T
3I0P
/s ≥ 1
or 2 ≤ I/3I
0p PICKUP
≤ 20 and T
3I0p Time Dial
/s ≥ 1
Defined times 1 % of setting value or 10 ms