Breaker Failure Protection 50BF
Setting Ranges/Increments
Pickup threshold 50BF Pickup
for Ι
Nom
= 1 A
0.05 A to 20.00 A Increments 0.01 A
for Ι
Nom
= 5 A
0.25 A to 100.00 A
Pickup threshold 50NBF Pickup
for Ι
Nom
= 1 A
0.05 A to 20.00 A Increments 0.01 A
for Ι
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
Times
Pickup times
- for internal start
- for external start
dropout time
dropout ratio
is included in the delay time
is included in the delay time
approx. 25 ms
1)
= 0.95(minimum hysteresis between pickup
and tripping ≥ 32.5 mA)
1)
A further delay for the current may be caused by compensation in the secondary CT circuit.
Tolerances
Pickup threshold 50BF Pickup, 50NBF Pickup
3 % of setting value,
or 15 mA for Ι
Nom
= 1 A
or 75 mA for Ι
Nom
= 5 A
Time delay 50 BF TRIP Timer 1 % or 20 ms
Influencing Variables for Pickup Values
Auxiliary direct voltage in the range of 0.8 ≤ V
PS
/V
PSNom
≤ 1.15 1 %
Temperature in the range of 23.00 °F (-5 °C) ≤ Θ
amb
≤ 131.00 °F (55 °C) 0.5 %/10 K
Frequency in the range of 0.95 ≤ f/f
Nom
≤ 1.05 (f
Nom
= 50 Hz or 60 Hz) 1 %
Harmonics
- up to 10 % 3. harmonic
- up to 10 % 5. harmonic
1 %
1 %
4.19
Technical Data
4.19 Breaker Failure Protection 50BF
SIPROTEC Compact, 7SC80, Manual 557
E50417-G1140-C486-A8, Edition 07.2017
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