Yep, you can fence off the control board and remove the fuses before you work in the shredder, but every now and then some guy will hop over the fence and put new fuses in when he gets back from his tea break.
He He did something similiar was trying to make a circuit live so we replaced all empty fuse holders and turned on everything, 10 mins later angry tech turn saying we nearly killed him, pointed out the lack of a warning placard saying he was working on circuit. (not avation related i know but the same procdures apply)