SIRIUS 3RF34 solid-state switching devices   
3.4 Functions 
  SIRIUS Innovations 
328  System Manual, 01/2011, A8E56203870002-03 
3.4.1  Actuation of solid-state switching devices 
Solid-state contactors  
Solid-state contactors are used for the frequent switching on of motors. The switch-on 
command is sent to the solid-state contactor when the control voltage is connected to 
terminals A1/A2. The power semiconductors are actuated after a short dwell time has 
elapsed. 
Solid-state reversing contactors  
The solid-state reversing contactors are dimensioned for the frequent reversing of motors. 
Dependent upon which control input is activated, two pairs of power semiconductors are 
actuated. If both inputs are activated at the same time, the device locks and no current will 
flow. Changing from one direction of rotation to the other is locked for a period of approx. 50 
to 100 ms.