Figure 2-7: Frequency Sensitivity Of The N-Short-Circuit Releases - Siemens sirius System Manual

3RV1 circuit breakers
Frequency sensitivity of
the short-circuit
releases
Frequency converters
2-12
The characteristics of the short-circuit releases apply to frequencies of 50/
60 Hz. For lower frequencies, such as 16
to 400 Hz, and for direct current, appropriate correction factors have to be
taken into account.
The following characteristic curve illustrates the frequency sensitivity of the
short-circuit releases (calibrated to 12 times I
40
Tripping current
Change in %
30
20
10
0
-10
-20
-30
0 50
100

Figure 2-7: Frequency sensitivity of the n-short-circuit releases

The increase in tripping current is approximately 30% for DC voltage.
The thermal switch disconnectors do not have to be corrected when you
use frequency converters.
2
/ Hz, for higher frequencies up
3
+20%):
u
150 200 250 300 350 400 Hz
SIRIUS System Manual
GWA 4NEB 430 0999-02b