Siemens SINAMICS S120 Equipment Manual page 81

Remove the holder for securing the Control Unit.
If an additional component is to be flush-mounted to the left of the component, the holders
for securing the Control Unit must be removed.
Use suitable tools to lift the latching device
and push up the holder.
Equipment Manual for Booksize Power Units
Equipment Manual, (GH2), 03/2006 Edition, 6SL3097-2AC00-0BP3
Remove the holder.
3.2 Active Line Modules with Internal Air Cooling
The holder removed
Line Modules Booksize
3-15