1988 Mercury Topaz alternator belt keeps braking

Ok i got this 1988 Mercury Topaz that has been snapping alternator belt like crazy, and i cant figgure out why its doing this. I put on a new alternator, and had it checked out. On the belts theres no sign of wear, one belt only lasted me a week. Ive gone threw 10 - 11 belts trying to figgure whats going on, im sure that its not locking up the power streeing is fine and the serpentine belt is fine aswell, so if anyone has a clue as to what might be going on please reply.

im interested in peoples responses...i just lost an alternator belt on my 89 topaz....is did squeel alot until the belt broke...my brother thinks that all the pulleys need greased..im just waiting for it to cool off outside before i crack the hood open

After it cools spin various pulleys like the alternator,power steering pump,water pump,smog pump,idler pulley or ect, if you have one. If the bearings are rough or seized replace or install new bearings. Stand at the side and look at alignment if a spacer wasn't installed it will be visible. You can use a straight edge to check also.
One of these items is bad or the alignment is bad or the belt won't break or jump off.