TWO EMPLOYEES LOCKED & TAGGED OUT #2 MINE CONVEYOR. THEY DID NOT CHECK TO BE CERTAIN IT WAS DEENERGIZED. THE CRUSHER OPERATOR, UNAWARE THEY WERE WORKING ON #2 TAKE-UP PULLEY, WENT THROUGH THE START-UP PROCEDURE & STARTED BELT #2 THAT HAD A DISCONNECT SWITCH THAT HAD BEEN TAMPERED WITH. ONE EMPLOYEE WAS PULLED TOWARD THE TAKE-UP BUT WAS PULLED TO SAFETY BY A CO-WORKER.