Copper Ampacity Table
A professional copper ampacity reference tool to help engineers quickly query and select the appropriate copper busbar specifications. Based on industry standard test data, ensuring design safety and reliability.
Test Condition Description
Environmental Parameters
Ambient temperature: 40°C
Installation method: Horizontal placement
Material Characteristics
Material: C11000 Copper
Surface emissivity: 0.4
Test Standard
Conforms to ASTM B187/B187M standards
60-day field test values
| Size T×W (in / mm) |
Cross-Sectional Area | Weight kg/m |
Resistance μΩ/ft² |
30°C Rise | 50°C Rise | 65°C Rise | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| mm² | CM | SE | A | SE | A | SE | A | |||
| 1/16 x 1/2 (1.6×12.7mm) | 20.1 | 39.7 | 0.18 | 264.0 | 1.00 | 103 | 1.00 | 136 | 1.00 | 157 |
| 1/16 x 3/4 (1.6×19.1mm) | 30.3 | 59.7 | 0.27 | 175.0 | 1.00 | 145 | 1.00 | 193 | 1.00 | 225 |
| 1/16 x 1 (1.6×25.4mm) | 40.3 | 79.6 | 0.36 | 132 | 1.00 | 187 | 1.00 | 250 | 1.00 | 285 |
| 1/16 x 1 1/2 (1.6×38.1mm) | 60.5 | 119 | 0.54 | 87.7 | 1.00 | 270 | 1.00 | 355 | 1.00 | 410 |
| 1/16 x 2 (1.6×50.8mm) | 80.6 | 159 | 0.72 | 65.8 | 1.01 | 345 | 1.01 | 460 | 1.01 | 530 |
| 1/8 x 1/2 (3.2×12.7mm) | 40.3 | 79.6 | 0.36 | 132 | 1.00 | 153 | 1.00 | 205 | 1.00 | 235 |
| 1/8 x 3/4 (3.2×19.1mm) | 60.5 | 119 | 0.54 | 87.7 | 1.00 | 215 | 1.00 | 285 | 1.00 | 325 |
| 1/8 x 1 (3.2×25.4mm) | 80.6 | 159 | 0.72 | 65.8 | 1.01 | 270 | 1.01 | 360 | 1.01 | 415 |
| 1/8 x 1 1/2 (3.2×38.1mm) | 121.3 | 239 | 1.08 | 43.8 | 1.01 | 385 | 1.01 | 510 | 1.01 | 590 |
| 1/8 x 2 (3.2×50.8mm) | 161.3 | 318 | 1.44 | 32.9 | 1.02 | 495 | 1.02 | 660 | 1.02 | 760 |
| 1/8 x 2 1/2 (3.2×63.5mm) | 201.3 | 397 | 1.80 | 26.4 | 1.02 | 600 | 1.02 | 800 | 1.02 | 920 |
| 1/8 x 3 (3.2×76.2mm) | 241.9 | 477 | 2.16 | 21.9 | 1.03 | 710 | 1.03 | 940 | 1.03 | 1100 |
| 1/8 x 3 1/2 (3.2×88.9mm) | 282.6 | 558 | 2.51 | 18.8 | 1.04 | 810 | 1.03 | 1100 | 1.03 | 1250 |
| 1/8 x 4 (3.2×101.6mm) | 322.6 | 636 | 2.87 | 16.5 | 1.04 | 910 | 1.04 | 1200 | 1.04 | 1400 |
| 3/16 x 1/2 (4.8×12.7mm) | 60.5 | 119 | 0.54 | 87.7 | 1.00 | 195 | 1.00 | 260 | 1.00 | 300 |
| 3/16 x 3/4 (4.8×19.1mm) | 91.0 | 179 | 0.81 | 58.4 | 1.01 | 270 | 1.01 | 360 | 1.01 | 415 |
| 3/16 x 1 (4.8×25.4mm) | 121.3 | 239 | 1.08 | 43.8 | 1.01 | 340 | 1.01 | 455 | 1.01 | 520 |
| 3/16 x 1 1/2 (4.8×38.1mm) | 181.3 | 358 | 1.62 | 29.3 | 1.02 | 480 | 1.02 | 630 | 1.02 | 730 |
| 3/16 x 2 (4.8×50.8mm) | 241.9 | 477 | 2.16 | 21.9 | 1.03 | 610 | 1.03 | 810 | 1.03 | 940 |
| 3/16 x 2 1/2 (4.8×63.5mm) | 302.6 | 597 | 2.69 | 17.5 | 1.04 | 740 | 1.04 | 980 | 1.03 | 1150 |
| 3/16 x 3 (4.8×76.2mm) | 362.6 | 715 | 3.23 | 14.6 | 1.05 | 870 | 1.05 | 1150 | 1.04 | 1350 |
| 3/16 x 3 1/2 (4.8×88.9mm) | 423.2 | 835 | 3.76 | 12.5 | 1.07 | 990 | 1.06 | 1300 | 1.06 | 1500 |
| 3/16 x 4 (4.8×101.6mm) | 483.9 | 955 | 4.32 | 11.0 | 1.09 | 1100 | 1.08 | 1450 | 1.07 | 1700 |
| 1/4 x 1/2 (6.4×12.7mm) | 80.6 | 159 | 0.72 | 65.8 | 1.01 | 240 | 1.01 | 315 | 1.01 | 360 |
| 1/4 x 3/4 (6.4×19.1mm) | 121.3 | 239 | 1.08 | 43.8 | 1.01 | 320 | 1.01 | 425 | 1.01 | 490 |
| 1/4 x 1 (6.4×25.4mm) | 161.3 | 318 | 1.44 | 32.9 | 1.02 | 400 | 1.02 | 530 | 1.02 | 620 |
| 1/4 x 1 1/2 (6.4×38.1mm) | 241.9 | 477 | 2.16 | 21.9 | 1.03 | 560 | 1.03 | 740 | 1.03 | 860 |
| 1/4 x 2 (6.4×50.8mm) | 322.6 | 637 | 2.87 | 16.5 | 1.04 | 710 | 1.04 | 940 | 1.04 | 1100 |
| 1/4 x 2 1/2 (6.4×63.5mm) | 403.2 | 796 | 3.59 | 13.2 | 1.06 | 850 | 1.06 | 1150 | 1.06 | 1300 |
| 1/4 x 3 (6.4×76.2mm) | 483.9 | 955 | 4.32 | 11.0 | 1.08 | 990 | 1.08 | 1300 | 1.07 | 1550 |
| 1/4 x 3 1/2 (6.4×88.9mm) | 564.5 | 1110 | 5.03 | 9.40 | 1.10 | 1150 | 1.09 | 1500 | 1.09 | 1750 |
| 1/4 x 4 (6.4×101.6mm) | 645.2 | 1270 | 5.74 | 8.23 | 1.12 | 1250 | 1.11 | 1700 | 1.10 | 1950 |
| 1/4 x 5 (6.4×127.0mm) | 806.5 | 1590 | 7.19 | 6.58 | 1.16 | 1500 | 1.15 | 2000 | 1.14 | 2350 |
| 1/4 x 6 (6.4×152.4mm) | 967.7 | 1910 | 8.63 | 5.49 | 1.18 | 1750 | 1.17 | 2350 | 1.17 | 2700 |
| 3/8 x 3/4 (9.5×19.1mm) | 181.3 | 358 | 1.62 | 29.3 | 1.02 | 415 | 1.02 | 550 | 1.02 | 630 |
| 3/8 x 1 (9.5×25.4mm) | 241.9 | 477 | 2.16 | 21.9 | 1.03 | 510 | 1.03 | 680 | 1.03 | 790 |
| 3/8 x 1 1/2 (9.5×38.1mm) | 362.6 | 715 | 3.23 | 14.6 | 1.05 | 710 | 1.04 | 940 | 1.04 | 1100 |
| 3/8 x 2 (9.5×50.8mm) | 483.9 | 955 | 4.32 | 11.0 | 1.08 | 880 | 1.08 | 1150 | 1.07 | 1350 |
| 3/8 x 2 1/2 (9.5×63.5mm) | 605.2 | 1190 | 5.39 | 8.77 | 1.12 | 1050 | 1.10 | 1400 | 1.09 | 1600 |
| 3/8 x 3 (9.5×76.2mm) | 722.6 | 1430 | 6.47 | 7.35 | 1.15 | 1200 | 1.14 | 1600 | 1.13 | 1850 |
| 3/8 x 3 1/2 (9.5×88.9mm) | 845.2 | 1670 | 7.53 | 6.38 | 1.18 | 1350 | 1.16 | 1800 | 1.15 | 2100 |
| 3/8 x 4 (9.5×101.6mm) | 967.7 | 1910 | 8.63 | 5.49 | 1.20 | 1500 | 1.19 | 2000 | 1.18 | 2350 |
| 3/8 x 5 (9.5×127.0mm) | 1,212.9 | 2390 | 10.80 | 4.38 | 1.24 | 1800 | 1.23 | 2400 | 1.22 | 2800 |
| 3/8 x 6 (9.5×152.4mm) | 1,451.6 | 2860 | 12.93 | 3.66 | 1.27 | 2100 | 1.26 | 2800 | 1.24 | 3250 |
| 1/2 x 1 (12.7×25.4mm) | 322.6 | 637 | 2.87 | 16.5 | 1.04 | 620 | 1.04 | 820 | 1.04 | 940 |
| 1/2 x 1 1/2 (12.7×38.1mm) | 483.9 | 955 | 4.32 | 11.0 | 1.08 | 830 | 1.08 | 1100 | 1.07 | 1250 |
| 1/2 x 2 (12.7×50.8mm) | 645.2 | 1270 | 5.74 | 8.23 | 1.12 | 1000 | 1.11 | 1350 | 1.10 | 1550 |
| 1/2 x 2 1/2 (12.7×63.5mm) | 806.5 | 1590 | 7.19 | 6.58 | 1.16 | 1200 | 1.15 | 1600 | 1.14 | 1850 |
| 1/2 x 3 (12.7×76.2mm) | 967.7 | 1910 | 8.63 | 5.49 | 1.20 | 1400 | 1.19 | 1850 | 1.18 | 2150 |
| 1/2 x 3 1/2 (12.7×88.9mm) | 1,129.0 | 2230 | 10.06 | 4.70 | 1.24 | 1550 | 1.22 | 2100 | 1.21 | 2400 |
| 1/2 x 4 (12.7×101.6mm) | 1,290.3 | 2550 | 11.50 | 4.11 | 1.26 | 1700 | 1.25 | 2300 | 1.24 | 2650 |
| 1/2 x 5 (12.7×127.0mm) | 1,612.9 | 3180 | 14.37 | 3.29 | 1.32 | 2050 | 1.30 | 2750 | 1.29 | 3150 |
| 1/2 x 6 (12.7×152.4mm) | 1,935.5 | 3820 | 17.26 | 2.74 | 1.36 | 2400 | 1.34 | 3150 | 1.33 | 3650 |
| 1/2 x 8 (12.7×203.2mm) | 2,580.6 | 5090 | 23.06 | 2.06 | 1.42 | 3000 | 1.40 | 4000 | 1.39 | 4600 |
Application Guide
Current Capacity Selection
- It is recommended to leave a 25-30% margin
- Consider actual heat dissipation conditions
Degradation Usage
- High altitude areas: thin air
- Limited ventilation conditions
- Side-by-side or vertical installation
Installation Suggestions
- Side-by-side spacing ≥ copper busbar width
- Ensure good ventilation
Technical Standards
- ASTM B187/B187M: Copper busbar standard specifications
- IEC 60890: Temperature rise calculation method
- GB/T 7251.12-2013: Low-voltage switchgear and control equipment