Ampacities of Copper No. 110 Busbars - Ampacities in the table below are for bus bars having an emissivity of 0.4. This was observed on samples exposed for 60 days in an industrial environment, and it is probably identical to that of bus bars in service.
| Dimensions, In. | Area | Weight Per Foot, Lb | DC Resistance at 20° C, Microhms Per Ft | |
|---|---|---|---|---|
| Square In. | Circular Mils, Thousands | |||
| 1/16 x 1/2 1/16 x 3/4 1/16 x 1 1/16 x 1 1/2 1/16 x 2 |
0.0312 0.0469 0.0625 0.0938 0.125 |
39.7 59.7 79.6 119 159 |
0.121 0.181 0.241 0.362 0.483 |
264.0 175.0 132.0 87.7 65.8 |
| 1/8 x 1/2 1/8 x 3/4 1/8 x 1 1/8 x 1 1/2 1/8 x 2 1/8 x 2 1/2 1/8 x 3 1/8 x 3 1/2 1/8 x 4 |
0.0625 0.0938 0.125 0.188 0.250 0.312 0.375 0.438 0.500 |
79.6 119 159 239 318 397 477 558 636 |
0.241 0.362 0.483 0.726 0.966 1.21 1.45 1.69 1.93 |
132.0 87.7 65.8 43.8 32.9 26.4 21.9 18.8 16.5 |
| 3/16 x 1/2 3/16 x 3/4 3/16 x 1 3/16 x 1 1/2 3/16 x 2 3/16 x 2 1/2 3/16 x 3 3/16 x 3 1/2 3/16 x 4 |
0.0938 0.141 0.188 0.281 0.375 0.469 0.562 0.656 0.750 |
119 179 239 358 477 597 715 835 955 |
0.362 0.545 0.726 1.09 1.45 1.81 2.17 2.53 2.90 |
87.7 58.4 43.8 29.3 21.9 17.5 14.6 12.5 11.0 |
| 1/4 x 1/2 1/4 x 3/4 1/4 x 1 1/4 x 1 1/2 1/4 x 2 1/4 x 2 1/2 1/4 x 3 1/4 x 3 1/2 1/4 x 4 1/4 x 5 1/4 x 6 1/4 x 8 1/4 x 10 1/4 x 12 |
0.125 0.188 0.250 0.375 0.500 0.625 0.750 0.875 1.00 1.25 1.50 2.00 2.50 3.00 |
159 239 318 477 637 796 955 1,110 1,270 1,590 1,910 2,550 3,180 3,820 |
0.483 0.726 0.966 1.45 1.93 2.41 2.90 3.38 3.86 4.83 5.80 7.73 9.66 11.6 |
65.8 43.8 32.9 21.9 16.5 13.2 11.0 9.40 8.23 6.58 5.49 4.11 3.29 2.74 |
| 3/8 x 3/4 3/8 x 1 3/8 x 1 1/2 3/8 x 2 3/8 x 2 1/2 3/8 x 3 3/8 x 3 1/2 3/8 x 4 3/8 x 5 3/8 x 6 3/8 x 8 3/8 x 10 3/8 x 12 |
0.281 0.375 0.562 0.750 0.938 1.12 1.31 1.50 1.88 2.25 3.00 3.75 4.50 |
358 477 715 955 1,190 1,430 1,670 1,910 2,390 2,860 3,820 4,770 5,730 |
1.09 1.45 2.17 2.90 3.62 4.35 5.06 5.80 7.26 8.69 11.6 14.5 17.4 |
29.3 21.9 14.6 11.0 8.77 7.35 6.28 5.49 4.38 3.66 2.74 2.19 1.83 |
| 1/2 x 1 1/2 x 1 1/2 1/2 x 2 1/2 x 2 1/2 1/2 x 3 1/2 x 3 1/2 1/2 x 4 1/2 x 5 1/2 x 6 1/2 x 8 1/2 x 10 1/2 x 12 |
0.500 0.750 1.00 1.25 1.50 1.75 2.00 2.50 3.00 4.00 5.00 6.00 |
637 955 1,270 1,590 1,910 2,230 2,550 3,180 3,820 5,090 6,360 7,640 |
1.93 2.90 3.86 4.83 5.80 6.76 7.73 9.66 11.6 15.5 19.3 23.2 |
16.5 11.0 8.23 6.58 5.49 4.70 4.11 3.29 2.74 2.06 1.65 1.37 |
| 3/4 x 4 3/4 x 5 3/4 x 6 3/4 x 8 3/4 x 10 3/4 x 12 |
3.00 3.75 4.50 6.00 7.50 9.00 |
3,820 4,770 5,730 7,640 9,550 11,500 |
11.6 14.5 17.4 23.2 29.0 34.8 |
2.74 2.19 1.83 1.37 1.10 0.914 |
| Dimensions, In. | 30 °C Rise | 50 °C Rise | 65 °C Rise | |||
|---|---|---|---|---|---|---|
| Skin Effect Ratio at 70° C | 60-Hz Ampacity,* Amp | Skin Effect Ratio at 90° C | 60-Hz Ampacity, *Amp | Skin Effect Ratio at 105° C | 60-Hz Ampacity, *Amp | |
| 1/16 x 1/2 1/16 x 3/4 1/16 x 1 1/16 x 1 1/2 1/16 x 2 |
1.00 1.00 1.00 1.00 1.01 |
103 145 187 270 345 |
1.00 1.00 1.00 1.00 1.01 |
136 193 250 355 460 |
1.00 1.00 1.00 1.00 1.01 |
157 225 285 410 530 |
| 1/8 x 1/2 1/8 x 3/4 1/8 x 1 1/8 x 1 1/2 1/8 x 2 1/8 x 2 1/2 1/8 x 3 1/8 x 3 1/2 1/8 x 4 |
1.00 1.00 1.01 1.01 1.02 1.02 1.03 1.04 1.04 |
153 215 270 385 495 600 710 810 910 |
1.00 1.00 1.01 1.01 1.02 1.02 1.03 1.03 1.04 |
205 285 360 510 660 800 940 1,100 1,200 |
1.00 1.00 1.01 1.01 1.02 1.02 1.03 1.03 1.04 |
235 325 415 590 760 920 1,100 1,250 1,400 |
| 3/16 x 1/2 3/16 x 3/4 3/16 x 1 3/16 x 1 1/2 3/16 x 2 3/16 x 2 1/2 3/16 x 3 3/16 x 3 1/2 3/16 x 4 |
1.00 1.01 1.01 1.02 1.03 1.04 1.05 1.07 1.09 |
195 270 340 480 610 740 870 990 1,100 |
1.00 1.01 1.01 1.02 1.03 1.04 1.05 1.06 1.08 |
260 360 455 630 810 980 1,150 1,300 1,450 |
1.00 1.01 1.01 1.02 1.03 1.03 1.04 1.06 1.07 |
300 415 520 730 940 1,150 1,350 1,500 1,700 |
| 1/4 x 1/2 1/4 x 3/4 1/4 x 1 1/4 x 1 1/2 1/4 x 2 1/4 x 2 1/2 1/4 x 3 1/4 x 3 1/2 1/4 x 4 1/4 x 5 1/4 x 6 1/4 x 8 1/4 x 10 1/4 x 12 |
1.01 1.01 1.02 1.03 1.04 1.06 1.08 1.10 1.12 1.16 1.18 1.23 1.27 1.31 |
240 320 400 560 710 850 990 1,150 1,250 1,500 1,750 2,250 2,700 3,150 |
1.01 1.01 1.02 1.03 1.04 1.06 1.08 1.09 1.11 1.15 1.17 1.22 1.26 1.30 |
315 425 530 740 940 1,150 1,300 1,500 1,700 2,000 2,350 3,000 3,600 4,200 |
1.01 1.01 1.02 1.03 1.04 1.06 1.07 1.09 1.10 1.14 1.17 1.21 1.25 1.28 |
360 490 620 860 1,100 1,300 1,550 1,750 1,950 2,350 2,700 3,450 4,200 4,900 |
| 3/8 x 3/4 3/8 x 1 3/8 x 1 1/2 3/8 x 2 3/8 x 2 1/2 3/8 x 3 3/8 x 3 1/2 3/8 x 4 3/8 x 5 3/8 x 6 3/8 x 8 3/8 x 10 3/8 x 12 |
1.02 1.03 1.05 1.08 1.12 1.15 1.18 1.20 1.24 1.27 1.33 1.38 1.42 |
415 510 710 880 1,050 1,200 1,350 1,500 1,800 2,100 2,650 3,200 3,700 |
1.02 1.03 1.04 1.08 1.10 1.14 1.16 1.19 1.23 1.26 1.31 1.36 1.40 |
550 680 940 1,150 1,400 1,600 1,800 2,000 2,400 2,800 3,550 4,300 5,000 |
1.02 1.03 1.04 1.07 1.09 1.13 1.15 1.18 1.22 1.24 1.30 1.35 1.38 |
630 790 1,100 1,350 1,600 1,850 2,100 2,350 2,800 3,250 4,100 4,900 5,800 |
| 1/2 x 1 1/2 x 1 1/2 1/2 x 2 1/2 x 2 1/2 1/2 x 3 1/2 x 3 1/2 1/2 x 4 1/2 x 5 1/2 x 6 1/2 x 8 1/2 x 10 1/2 x 12 |
1.04 1.08 1.12 1.16 1.20 1.24 1.26 1.32 1.36 1.42 1.47 1.52 |
620 830 1,000 1,200 1,400 1,550 1,700 2,050 2,400 3,000 3,600 4,200 |
1.04 1.08 1.11 1.15 1.19 1.22 1.25 1.30 1.34 1.40 1.45 1.51 |
820 1,100 1,350 1,600 1,850 2,100 2,300 2,750 3,150 4,000 4,800 5,600 |
1.04 1.07 1.10 1.14 1.18 1.21 1.24 1.29 1.33 1.39 1.44 1.50 |
940 1,250 1,550 1,850 2,150 2,400 2,650 3,150 3,650 4,600 5,500 6,400 |
| 3/4 x 4 3/4 x 5 3/4 x 6 3/4 x 8 3/4 x 10 3/4 x 12 |
1.42 1.48 1.52 1.60 1.67 1.72 |
2,050 2,400 2,800 3,500 4,200 4,900 |
1.40 1.46 1.50 1.58 1.64 1.69 |
2,750 3,250 3,750 4,700 5,600 6,500 |
1.38 1.44 1.48 1.56 1.62 1.67 |
3,150 3,750 4,300 5,400 6,500 7,500 |
| * Applicable to typical in-service conditions (indoors, 40°C ambient temperature), horizontal run on edge, and free from external magnetic influences. | ||||||