Siemens 3VA1 100 A, Manual

Page: 520 / 532

Glossary
3VA molded case circuit breakers
520
Manual, 04/2015, A5E03603177010-02
Making capacity
The making capacity is the value of the prospective making current which the switching
device can safely conduct at the instant of closing under prescribed conditions for a specific
circuit.
For molded case circuit breakers, the making capacity is expressed as the maximum
possible instantaneous value of the potential prospective current at the input terminals for
the specified voltage.
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 rated breaking capacity is the maximum current that can be interrupted by a switching
device under certain conditions.
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.