Clarify light sensor wiring diagram
The instructions say "after switch",  so that's that. The switch may have functions which require this.  Also, you have to obey the labeling and instructions, because the UL listing  (or comparable; CE isn't) is only good for labeled uses.  

Some motion sensors need power 24x7 to function reliably.  That is because they need to "remember" the quiescent state of the room, and the ambient light levels that occur in normal light cycles in this location.  If you have a motion sensor that seems to bungle either of those things, try leaving its power on, an see if it adjusts after 48 hours.