Siemens 7SK80 - Breaker Failure Protection 50 BF

Technical Data
4.18 Breaker Failure Protection 50BF
SIPROTEC, 7SK80, Manual
E50417-G1140-C344-A5, Release date 11.2012
397
4.18 Breaker Failure Protection 50BF
Setting Ranges / Increments
Times
Tolerances
Influencing Variables for Pickup Values
1)
A further delay for the current may be caused by compensation in the secondary CT circuit.
Pickup threshold 50-1 BF for I
Nom
= 1 A 0.05 A to 20.00 A Increments 0.01 A
for I
Nom
= 5 A 0.25 A to 100.00 A
Pickup threshold 50N-1 BF for I
Nom
= 1 A 0.05 A to 20.00 A Increments 0.01 A
for I
Nom
= 5 A 0.25 A to 100.00 A
Time delay 50 BF trip timer 0.06 s to 60.00 s or ∞ Increments 0.01 s
Pickup times
- for internal start
- for external start
Dropout time
Dropout ratio
Included in time delay
Included in time delay
approx. 25 ms
= 0,95 (minimal hysteresis between pickup and
tripping ≥ 32,5 mA)
Pickup threshold 50-1 BF, 50N-1 BF 3 % of setting value,
or 15 mA for I
Nom
= 1 A
or 75 mA for I
Nom
= 5 A
Time delay 50 BF trip timer 1 % or 20 ms
Auxiliary DC voltage in range 0.8 ≤ V
Aux
/V
AuxNom
≤ 1.15 1 %
Temperature in range
–5 °C (41 °F) ≤ Θ
amb
≤ 55 °C (131 °F)
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%