Description
2.3 Protection system
3WA Air Circuit Breakers
Equipment Manual, 05/2021, 92310000002-03
47
2.3.3 Guideline for setting the protection parameters
The protection parameters of the electronic trip unit depend on the technical environment
(e.g. power distribution equipment and applications) and the type of equipment to be
protected. Therefore, the protection settings must be calculated according to the applicable
regulations and the electronic trip unit must be set with these calculated parameters.
SIMARIS design
The Siemens SIMARIS design software tool is a simple and reliable tool for calculating and
dimensioning networks.
For more information on SIMARIS design, refer to the Internet
(
https://www.siemens.com/simaris
).
2.3.4 Time-current characteristic
The time-current characteristic of the circuit breakerās electronic trip unit is determined by the
individual sub-characteristics of the active protective functions, e.g. long time LT, short time
ST, and short-circuit protection INST.