Siemens BETA Low-Voltage Circuit Protection

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BETA Protecting
Miniature Circuit Breakers
Configuration
1/77 Siemens ET B1 · 10/2008
1
* You can order this quantity or a multiple thereof.
Back-up protection miniature circuit breakers/fuses
If the maximum short-circuit current of the miniature circuit
breaker at the installation site is unknown, or if the specified
rated switching capacity is exceeded, an additional protective
device must be connected upstream as back-up protection to
prevent overloading of the miniature circuit breaker. This is
usually a fuse.
The following table shows the short-circuit currents in kA up to
which back-up protection is guaranteed when using fuses
according to DIN VDE 0636-21.
Limit values of back-up protection miniature circuit breakers/fuses in kA
Downstream miniature circuit breakers Upstream fuses
In [A] 50 A 63 A 80 A 100 A 125 A 160 A
5SY6
0.3 ... 4 No back-up protection required up to 50 kA
6 50 50 50 50 50 35
8 50 50 50 50 50 35
10 50 50 50 50 50 35
13 50 50 50 35 35 30
16 50 50 50 35 30 30
20 50 50 50 35 25 25
25 50 50 50 35 30 25
32 50 50 50 35 30 25
40 50 50 50 50 25 15
50 50 50 50 50 25 15
63 50 50 35 25 25 15
5SY4, 5SY7
0.3 ... 6 No back-up protection required
8 50 50 50 50 45 45
10 50 50 50 50 45 45
13 50 50 50 45 40 35
16 50 50 50 45 40 35
20 50 50 50 40 35 30
25 50 50 50 40 35 30
32 50 50 50 45 40 30
40 50 50 50 45 40 30
50 50 50 50 40 35 25
63 50 50 45 40 35 25
Test circuit data: Test cycle:
Up = 250 V According to EN 60947-2 (0 - C0)
p.f. = 0.3 ... 0.5
© Siemens AG 2008