Siemens SIRIUS 3RA, Equipment Manual

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Functions
5
Pre-assembled load feeders
In the 3RA2 fuseless load feeder, the 3RV2 motor starter protector takes on the dual function of
overload protection and short-circuit protection. Upstream protective devices such as melting
fuses or limiters are superfluous, as the load feeder is capable of withstanding short circuits up
to 150 kA at 400 V.
The 3RT2 contactor is suitable for extremely complex switching tasks requiring maximum
endurance.
The trip class on all pre-assembled 3RA2 feeders is CLASS 10.
Self-assembled load feeders
Thanks to the flexible SIRIUS modular system, load feeders can be assembled for the most
diverse requirements.
These load feeders can be fuseless or fused. Load feeders for starting motors can be assembled
for the following startup types, for example:
• Direct-on-line start
• Reversing start
• Star-delta (wye-delta) start
• Soft start
• Configuration with solid-state switching devices for high switching frequencies
In the case of a configuration with overload relay, a tripping class up to CLASS 30 can be set. In
the case of a configuration with SIMOCODE, a tripping class up to CLASS 40 can be set.
Reference
More information ... Can be found ...
About the functions of motor starter protectors In the "References" appendix under "Manuals - SIR‐
IUS Modular System (Page 138)" in the "SIRIUS -
SIRIUS 3RV motor starter protectors" manual.
SIRIUS 3RA Load Feeders
Equipment Manual, 02/2022, A5E03656507520A/RS-AC/004
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