SIRIUS 3RA28 function modules for mounting on 3RT2 contactors 
  7.2 Product description 
SIRIUS Innovations 
System Manual, 01/2011, A8E56203870002-03 
649 
7.2.4  3RA28 function modules 
Function module for direct-on-line start (solid-state timing relays with semiconductor output/solid-state 
time-delay auxiliary switches) 
 
1  Timing relay attachment 
2  Time range selector switch:  Sets the time base (1 s, 10 s, 100 s) 
3  Operating time adjustment switch:  Sets the relative time (5 to 100%) 
4  Mechanical plunger:   Indicates the switching state of the contactor 
5  Screw-type/spring-loaded 
connections: 
The terminals are available as both screw-type and 
spring-loaded connections. 
Figure 7-2  Solid-state timing relay with semiconductor output/solid-state time-delay auxiliary 
switches  
Function module for star-delta (wye-delta) start 
The function module for star-delta (wye-delta) start comprises a basic module with integrated 
control logic and two coupling modules of the same type. 
 
 
 
1  Basic module with integrated control logic 
2  Coupling module 
3  Coil control:   Basic module: Voltage measurement at the line contactor 
Coupling module: Controls the contactor below 
4  Ribbon cable:   Electrical connection of modules 
5  Slot for connecting cable:  Routes the supply voltage and electrical interlock 
6  Time range selector switch:  Sets the time base (10 s, 30 s, 60 s) 
7  Operating time adjustment switch:  Sets the relative time (5 to 100%) 
8  Mechanical plunger:  Indicates the switching state of the contactor 
Figure 7-3  Basic module and coupling modules for the contactor assembly for star-delta (wye-delta) 
start