EMPLOYEE WAS FUELING PORTABLE COMPRESSOR DIESEL TANK WHILE EQUIPMENT WAS OPERATING. HE REACHED TO GRAB THE FUEL CAP WHEN HIS RIGHT HAND RING FINGER GOT CAUGHT IN THE FAN BLADES OF THE ALTERNAT OR. HE WAS TAKEN FOR MEDICAL TREATMENT WHERE AMPUTATION OF THE RIGHT RING FINGER TO DISTAL INTERPHALANGIAL JOINT WAS REQUIRED.