Siemens SIMATIC ET 200SP System Manual page 43

Procedure
To mount the mechanical bracket, proceed as follows:
1. Insert the mechanical bracket into the opening at the bottom of the BaseUnit.
You use the same mechanical bracket for both mounting rails, rotated through 180°
respectively.
2. Hook the BaseUnit into the mounting rail.
3. Insert the mechanical bracket into the BaseUnit.
4. Screw the mechanical bracket securely onto the mounting panel. Use an M4 screw.
Result: You achieve improved stability by using the mechanical bracket.
Motor starter
System Manual, 04/2016, A5E35582704002A/RS-AA/001
4.4 Mounting the mechanical bracket for the BaseUnit
Mounting
43