Fuses are first rated by the AC and/or DC circuit voltage into which they can be safely applied. A fuse used in an AC circuit performs differently than when installed in a DC circuit. Generally, fuse AC voltage ratings coincide with the utility supply, e.g., 110V, 240V, 415V, etc. This means that a fuse is suitable for use with these nominal voltages and it can be 15% higher than the nominal rating. The nominal DC voltage ratings should not be exceeded. Fuses are insensitive to voltage changes within their ratings, so selecting the proper voltage rating is strictly a safety issue. Fuses can operate at any voltage below or equal to their rated voltage.