Siemens SIRIUS 3RF Series

System overview
1.7 Components and combinations
SIRIUS Innovations
66 System Manual, 01/2011, A8E56203870002-03
1.7.5.1 SIRIUS 3RA28 function modules for mounting on SIRIUS 3RT2 contactors
3RA28 function modules for mounting on 3RT2 contactors
SIRIUS 3RA28 function modules for mounting on SIRIUS 3RT2 contactors enable the
control circuit wiring to be reduced significantly. With star-delta (wye-delta) starters, for
example, they replace the control circuit wiring in its entirety.
Table 1- 18 3RA28 function modules for mounting on 3RT2 contactors
Area Customer benefits
Functions
 Direct-on-line, reversing, and star-delta (wye-delta) start
 Time-delayed switching of contactors (0.05 to 100 s)
 ON-delay and OFF-delay versions
 Star-delta (wye-delta) function module without extra control circuit wiring
 Switch position indication for the contactor via a mechanical plunger
Dimensioning and
design
 Only one version for S00 and S0
 Suitable for control voltages of 24 to 240 V AC/DC
 Contactor coil controlled via semiconductor output
 Star-delta (wye-delta) switchover 0.5 to 60 s
 Star-delta (wye-delta) changeover delay: 50 ms
Mounting
advantages
 Easy plug-on assembly of a starter, without tools
 Removable terminals
 Screw-type and spring-loaded terminals
Application
areas/customer
benefits
 Assembly of star-delta (wye-delta) starters, including timing function and
electrical interlock, without additional wiring
 Universal applicability thanks to wide voltage and time ranges