If your scanner has been set up at a static location, you do not need to turn it off.
If you are going to move your scanner to another location, follow the correct power down procedure:
How to power down your scanner:
1) Turn off the scanner by hitting the turn off button on the UI
2) Wait till you see the screen is completely blank
3) Wait 5 seconds
4) Turn the power off by toggling the power switch to OFF:
If you are doing a power cycle (intending to turn it on again), wait 10 seconds before changing the power switch to ON.