SIRIUS 3RT2 contactors/contactor assemblies   
2.4 Configuration 
  SIRIUS Innovations 
128  System Manual, 01/2011, A8E56203870002-03 
2.4.8.3  Contactors for railway applications 
Special versions of the power contactors and contactor relays with an extended temperature 
range are available for use in railway applications, with voltages of 24 V DC and 110 V DC in 
the control circuit. Different coil voltages can be obtained on request from Technical 
Assistance (www.siemens.com/lowvoltage/techni
cal
-assistance). 
The relevant requirements are met for size S00 by means of a series resistor and for size S0 
via an electronic drive. Coupling relays for railway applications are also available. 
The extended temperature range of -40 to +70 °C applies to all contactors for railway 
applications. 
Reference 
 
More information ...  Can be found in the chapter titled ... 
About the extended operating ranges of the 
individual contactor versions  
Overview (Page 127) 
Contactors with series resistor (size S00) 
The DC magnet system of these contactors is switched on with a defined overexcitation due 
to the extended operating range of 0.7 to 1.25 x U
S
. Following switch-on, the series resistor 
switches over to holding excitation.  
Design 
The contactors are available with a plug-on module containing the series resistor (the NC 
contact required for switchover is integrated in the basic device and already fully wired). The 
DC magnet coils of the contactor versions are fitted with suppressor diodes to provide 
protection against overvoltage as standard. The opening delay is consequently 2 ms to 5 ms 
longer than for standard contactors. 
The power contactors with series resistor are identified by the suffix -0LA0 as the 
13th to 16th digits of the order number (3RT201.-2K.42-0LA0). The order number for 
contactor relays with series resistor is 3RH2122-2K.40-0LA0. 
 
 
Note 
According to DIN EN 50005, these versions of contactor relays and motor contactors can be 
expanded by means of a 4-pole auxiliary switch block on the front Two lateral auxiliary 
switch blocks can also be mounted on the motor contactor. 
 
Mounting instruction 
Motor contactors and contactor relays of size S00 are approved for side-by-side mounting at 
ambient temperatures of up to 70 °C. 
 
Contactors with electronic drive (size S0) 
The 3RT202.-.X.40-0LA2 motor contactors are controlled via an electronic drive, which 
guarantees an operating range of 0.7 to 1.3 U
S
 at an ambient temperature of 70 °C.