regarding blowinn the scsi fuse

a while back i bought an external 250mb zip drive and i thought it was scsi but it's not (parellel port), but before i figured that out,i was tryin to get it to work and eventually i pulled the plug out when they were both on, would the fuse have blown if i didnt even have an actual scsi zip drive connected to it ? wut causes the damage to the fuse ?
hope i can get some help
Peace

my fuse broke on the back of scsi port in the mpc and provided much drama, but all is better now.