Wire size electrical load and fuse size Table 2. Relationship between wire size, electrical load and fuse size. Gauge size Maximum watts at 115V Maximum watts at 230V Fuse or breaker amps 14 1,725 3,450 15 12 2,300 4,600 20 10 3,450 6,900 30 8 4,600 9,200 40 6 6,325 12,750 55 4 8,050 16,100 70 2 10,925 21,850 95 0 14,375 28,750 125