Short-Circuit Strength - Siemens SINAMICS G130 Engineering Manual

Shrouding cover for a circuit breaker
Protective functions
The standard circuit breakers feature protective functions in compliance with equipment class ETU 25B.
The integrated electronic overcurrent release provides the following functionality:
•
Overload protection (L release)
•
Short-time delayed short-circuit protection (S release)
•
Instantaneous short-circuit protection (I release)
The basic protective functions of the overcurrent release operate reliably without an additional auxiliary voltage. The
required energy is provided by energy converters in the breaker. The overcurrent release electronics bases its
current evaluation on an RMS calculation.
The individual functions are parameterized by a rotary coding switch.
Overload protection – L release
The setting value IR defines the maximum continuous current at which the breaker can operate without tripping. The
time-lag class tR defines the maximum period of overload before the breaker trips.
Setting values for IR = (0.4 / 0.45 / 0.5 / 0.55 / 0.6 / 0.65 / 0.7/ 0.8 / 0.9 / 1.0) x I
Setting values for tR = 10 s (with 6 x IR)
Short-time delayed short-circuit protection– S release
The overcurrent release provided allows tripping as a result of short-circuit current Isd to be delayed by the period
tsd. This means that short-circuit protection can be applied selectively in switchgear with several time-grading levels.
Setting values for Isd = (1.25 / 1.5 / 2 / 2.5 / 3 / 4 / 6 / 8 / 10 / 12) x I
Setting values for tsd = 0 / 0.02(M) / 0.1 / 0.2 / 0.3 / 0.4 s
Instantaneous short-circuit protection with an adjustable response value lower than the preset response value li can
be implemented with the setting value tsd = 0 s.
Instantaneous short-circuit protection– I release
The circuit breaker trips instantaneously when the current exceeds the setting value for Ii.
Setting values for Ii ≥  2 0 x I

Short-circuit strength

The Line Connection Modules are mechanically designed to withstand the tolerance limits of the circuit breaker.
Higher short-circuit strengths are available on request.
(preset), max. = 50 kA
rated
SINAMICS S120 Cabinet Modules
Engineering Information
rated
rated
SINAMICS Engineering Manual - May 2008
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