Siemens Sentron 3VA, Руководство пользователя

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Glossary
3VA molded case circuit breakers with UL and IEC certification
480
Manual, 01/2019, L1V30435333-01
MANUAL
Local, manual operating mode of motor operators.
Protective characteristic
The protective characteristic is determined by the rated operational current and the setting
and tripping values of the circuit breaker.
Rated breaking capacity
The circuit breaker must disconnect this current three times without damage. This is followed
by, among other things, a check of the operating characteristics. That is, the switch must
subsequently be able to conduct the operational current and to still switch at least once.
Rated frequency
Design frequency for a switching device and reference value for other characteristics of the
device.
Rated making capacity
The rated making capacity is the maximum current that a switching device can conduct at
the instant of closing in accordance with the utilization category at the relevant rated
operational voltage.
Rated operational current
The rated operational current
I
n
for molded case circuit breakers is equivalent to the rated
uninterrupted current
I
U
and to the conventional free-air thermal current
I
th
.
Rated operational voltage
The rated operational voltage
U
e
of a switching device, e.g. a molded case circuit breaker, is
the voltage which serves as a reference to state other characteristics of the device. The
maximum rated operational voltage must never be higher than the rated insulation voltage.
With multi-phase circuits, the specified voltage is generally the phase-to-phase voltage.
Rated peak withstand current, impulse short-circuit current
Maximum permissible instantaneous (peak) value of the prospective short-circuit current in
the current path under the highest load. It characterizes the dynamic short-circuit strength of
a switching device.