I am looking to put http://www.centralvacuummotor.com/Domel/496%203%20720-2%20P.pdf one these bad boys in my vacuum I have 12/3 to wire it up all I need is a 20 amp switch and 3/4" males to1/2" female with alock nut. where the coed exit is exactly 3/4" will There be a sandblasting effect on my bags