It means you only get 30 pts damage if you do nothing but hang around and soak it up.
Good call in decoupling it from the framerate... removes a potential bug or two to boot.
Question, though - what would happen if you had like six of those little bastards going off at the same time? Dunno if you have any kind of limiting factor for that already, but I could see a pile of 'em (or even semi-spam of 3) at one time tearing the shit out of anything in range.