The term FUSE RATING UNIT is composed of three words: FUSE, RATING, and UNIT. The first word, FUSE, refers to a device that is used to protect electrical circuits from overloads by breaking the circuit when too much current flows through it. The second word, RATING, refers to the amount of current that a FUSE can safely handle before it will break the circuit. The third word, UNIT, refers to the measurement of the RATING, which is usually expressed in amperes (amps). The acronym AMP, which stands for ampere, is a three-letter abbreviation for this UNIT of measurement.