7SR11 & 7SR12 Performance Specification
ยฉ2017 Siemens Protection Devices Limited Chapter 3 Page 53 of 56
3.2 50BF Circuit Breaker Fail
3.2.1 Reference
Parameter Value
Is
Setting
0.050, 0.055โฆ 2.0 xIn
I4
Setting
0.050, 0.055โฆ 2.0 xIn
t
CBF1
Stage 1 Delay setting 20, 25โฆ 60000ms
t
CBF2
Stage 2 Delay setting 20, 25โฆ 60000ms
3.2.2 Operate and Reset Level
Attribute Value
I
op
Operate level
100 % Is, ยฑ 5 % or ยฑ 1% In
I
reset
Reset level
<100 % I
op
, ยฑ 5 % or ยฑ 1% In
Repeatability
ยฑ 1 %
Variation
-10 ยฐC to +55 ยฐC
โค 5 %
f
nom
ยฑ 5 %
โค 5 %
3.2.3 Operate and Reset Time
Attribute Value
t
op
Stage 1
t
CBF1
, ยฑ 1 % or ยฑ 20ms
Stage 2
t
CBF2
, ยฑ 1 % or ยฑ 20ms
Repeatability
ยฑ 1 % or ยฑ 20ms
Overshoot < 2 x 20ms
Disengaging time < 20ms