DC Ampacity Tables - Copper Sizes (Inches) 1 Bar 2 Bars 3 Bars 4 Bars Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper A1 B2 A1 B2 A1 B2 A1 B2 1/8 x 1/2 79.6 154 152 N/A N/A N/A 1/8 x 3/4 119.4 215 212 N/A N/A N/A 1/8 x 1 159.2 275 271 N/A N/A N/A 1/8 x 1 1/2 238.7 390 385 N/A N/A N/A 1/8 x 2 318.3 503 496 N/A N/A N/A 1/4 x 1/2 159.2 238 234 N/A N/A N/A 1/4 x 1 318.3 409 403 N/A N/A N/A 1/4 x 1 1/2 477.5 572 564 N/A N/A N/A 1/4 x 2 636.6 731 721 1,273.0 1,301 1,259 N/A 2,546.0 2,426 2,313 1/4 x 2 1/2 795.8 887 869 N/A N/A N/A 1/4 x 3 954.9 1,040 1,019 1910.0 1,834 1,735 N/A 3,820.0 3,394 3,123 1/4 x 3 1/2 1,114.0 1,192 1,152 N/A N/A N/A 1/4 x 4 1,273.0 1,342 1,295 2,546.0 2,350 2,163 3,820.0 3,342 2,996 5,093.0 4,328 3,819 1/4 x 6 1,910.0 1,931 1,820 3,820.0 3,352 2,937 5,730.0 4,745 3,992 7,639.0 6,130 5,026 1/4 x 8 2,546.0 3,092 2,828 5,093.0 4,325 3,583 7,640.0 6,105 4,770 10,186.0 7,872 5,916 3/8 x 1 477.5 524 517 N/A N/A N/A 3/8 x 1 1/2 716.2 724 714 N/A N/A N/A 3/8 x 2 954.9 919 906 N/A N/A N/A 3/8 x 2 1/2 1,194.0 1,110 1,087 N/A N/A N/A 3/8 x 3 1,432.0 1,298 1,272 N/A N/A N/A 3/8 x 4 1,910.0 1,667 1,612 N/A N/A N/A 3/8 x 6 2,865.0 2,388 2,250 N/A N/A N/A 3/8 x 8 3,820.0 3,092 2,828 N/A N/A N/A 1/2 x 1 636.6 632 622 N/A N/A N/A 1/2 x 1 1/2 954.9 863 851 N/A N/A N/A 1/2 x 2 1,910.0 1,865 1,787 2,546.0 1,961 1,902 N/A N/A 1/2 x 3 2,865.0 2,616 2,432 3,820.0 2,715 2,577 N/A N/A 1/2 x 4 2,546.0 1,951 1,887 5,093.0 3,445 3,182 7,639.0 4,918 4,437 10,168.0 6,384 5,673 1/2 x 6 3,820.0 2,783 2,623 7,638.0 4,861 4,275 11,459.0 6,902 5,848 15,278.0 8,933 7,392 1/2 x 8 5,093.0 3,596 3,289 10,186.0 6,236 5,189 15,278.0 8,824 6,950 20,371.0 11,395 8,659 Sizes (Inches) 5 Bars 6 Bars 7 Bars 8 Bars Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper A1 B2 A1 B2 A1 B2 A1 B2 1/4 x 4 6,365.0 5,312 4,637 7,610.0 6,295 5,452 N/A N/A 1/4 x 6 9,550.0 7,512 6,048 11,410.0 8,891 7,064 13,370.0 10,270 8,076 15,280.0 11,645 9,086 1/4 x 8 12,710.0 9,634 7,041 15,330.0 11,395 8,154 17,882.0 13,150 9,259 20,372.0 14,905 10,360 1/2 x 4 12,732.0 7,847 6,915 15,278.0 9,309 8,148 N/A N/A 1/2 x 6 19,098.0 10,960 8,921 22,918.0 12,980 10,445 26,737.0 15,000 11,960 30,557.0 17,020 13,475 1/2 x 8 25,464.0 13,960 10,340 30,557.0 16,520 12,005 35,650.0 19,080 13,660 40,742.0 21,635 15,310 Sizes (Inches) 9 Bars 10 Bars 11 Bars 12 Bars Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper Area (cm) Ampacity Copper A1 B2 A1 B2 A1 B2 A1 B2 1/4 x 6 17,190.0 13,020 10,095 19,100.0 14,400 11,100 21,010.0 15,775 12,105 22,920.0 17,150 13,110 1/4 x 8 22,914.0 16,660 11,455 25,460.0 18,415 12,545 28,013.0 20,170 13,640 30,560.0 21,925 14,725 1/2 x 6 34,376.0 19,040 14,985 38,190.0 21,060 16,495 N/A N/A 1/2 x 8 45,835.0 24,190 16,955 50,928.0 26,745 18,600 N/A N/A A1. The ampacity rating is based on a 30°C rise above a 40°C ambient. The bars are run with their long axis vertical. The spacing between bars is equal to or more than their thickness, and the bars are run in a horizontal plane. B2. Ampacity rating to be used when the long axis of the bars is in the horizontal plane, or when the spacing between bars is less than the thickness of the bars, or when the bars are run in a vertical direction. 3. The minimum bending radius for copper is equal to the thickness of the bar. The minimum bending radius for aluminum is equal to twice the thickness of the bar. The surface roughening that may occur at the bend is not serious as long as it is only a surface condition. 4. The copper bus bar is ETP-110 100% IACS (International Annealed Copper Standard) conductivity (0.15328 ohm-gram/square meter) per ASTM B187. The resistivity is 10.371 ohm circular mils/foot at 20°C surface of the cable. The minimum bend radii may be reduced only if specifically allowed by the conductor manufacturer. Other Bus Bar Links Aluminum Bus Bar General Information Aluminum Bus Bar Chart Copper Bus Bar Quick Selector Copper Bus Bar General Information Copper Bus Bar Ampacity Chart Copper Bus Bar Horizontal Properties Copper Bus Bar Vertical Properties Copper Emissivity Chart
EMS Highlights      |      Products      |      Equipment      |      About      |      Contact Us      |      Home      |      Privacy      |      Terms