Resistance Wire - Current vs. Temperature
Current Carrying Capacity of Straight Nickel Chromium Wire, Approximate amperes to heat a straight, oxidized wire in quiet air to given temperature
|
| °F | 400 | 600 | 800 | 1000 | 1200 | 1400 |
|---|
| °C | 205 | 315 | 427 | 538 | 649 | 760 |
|---|
AWG or
B & S | Inches
Dia. | Amperes |
|---|
| 15 | 0.057 | 7.2 | 10.0 | 12.8 | 16.1 | 20.0 | 24.5 |
| 16 | 0.051 | 6.4 | 8.7 | 10.9 | 13.7 | 17.0 | 20.9 |
| 17 | 0.045 | 5.5 | 7.5 | 9.5 | 11.7 | 14.5 | 17.6 |
| 18 | 0.040 | 4.8 | 6.5 | 8.2 | 10.1 | 12.2 | 14.8 |
| 19 | 0.036 | 4.3 | 5.8 | 7.2 | 8.7 | 10.6 | 12.7 |
| 20 | 0.032 | 3.8 | 5.1 | 6.3 | 7.6 | 9.1 | 11.0 |
| 21 | 0.0285 | 3.3 | 4.3 | 5.3 | 6.5 | 7.8 | 9.4 |
| 22 | 0.0253 | 2.9 | 3.7 | 4.5 | 5.6 | 6.8 | 8.2 |
| 23 | 0.0226 | 2.58 | 3.3 | 4.0 | 4.9 | 5.9 | 7.0 |
| 24 | 0.0201 | 2.21 | 2.9 | 3.4 | 4.2 | 5.1 | 6.0 |
| 25 | 0.0179 | 1.92 | 2.52 | 3.0 | 3.6 | 4.3 | 5.2 |
| 26 | 0.0159 | 1.67 | 2.14 | 2.60 | 3.2 | 3.8 | 4.5 |
| 27 | 0.0142 | 1.44 | 1.84 | 2.25 | 2.73 | 3.3 | 3.9 |
| 28 | 0.0126 | 1.24 | 1.61 | 1.95 | 2.38 | 2.85 | 3.4 |
| 29 | 0.0113 | 1.08 | 1.41 | 1.73 | 2.10 | 2.51 | 2.95 |
| 30 | 0.0100 | 0.92 | 1.19 | 1.47 | 1.78 | 2.14 | 2.52 |
| 31 | 0.0089 | 0.77 | 1.03 | 1.28 | 1.54 | 1.84 | 2.17 |
| 32 | 0.0080 | 0.68 | 0.90 | 1.13 | 1.36 | 1.62 | 1.89 |
| 33 | 0.0071 | 0.59 | 0.79 | 0.97 | 1.17 | 1.40 | 1.62 |
| 34 | 0.0063 | 0.50 | 0.68 | 0.83 | 1.00 | 1.20 | 1.41 |
| 35 | 0.0056 | 0.43 | 0.57 | 0.72 | 0.87 | 1.03 | 1.21 |
| 36 | 0.0050 | 0.38 | 0.52 | 0.63 | 0.77 | 0.89 | 1.04 |
| 37 | 0.0045 | 0.35 | 0.46 | 0.57 | 0.68 | 0.78 | 0.90 |
| 38 | 0.0040 | 0.30 | 0.41 | 0.50 | 0.59 | 0.68 | 0.78 |
| 39 | 0.0035 | 0.27 | 0.36 | 0.42 | 0.49 | 0.58 | 0.66 |
| 40 | 0.0031 | 0.24 | 0.31 | 0.36 | 0.43 | 0.50 | 0.57 |
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Current Carrying Capacity of Ribbon
Nickel Chromium Wire, At 1200°F Approximate | | Width-Inches |
|---|
| Thickness in Inches | 1/64 | 1/32 | 1/16 | 3/32 | 1/8 | 3/16 |
|---|
| Amps |
|---|
| 0.0063 | 1.56 | 2.89 | 5.5 | 8.2 | 8.2 | 16.6 |
| 0.0056 | 1.45 | 2.69 | 5.2 | 7.2 | 7.2 | 15.6 |
| 0.0050 | 1.35 | 2.52 | 4.9 | 6.8 | 6.8 | 14.7 |
| 0.0045 | 1.26 | 2.38 | 4.6 | 6.4 | 6.4 | 14.0 |
| 0.0040 | 1.18 | 2.23 | 4.1 | 6.0 | 6.0 | 13.1 |
| 0.0035 | 1.09 | 2.07 | 3.8 | 5.6 | 5.6 | 12.3 |
| 0.0031 | 1.01 | 1.94 | 3.6 | 5.3 | 5.3 | 11.5 |
| 0.0020 | — | — | — | — | — | — |
| 0.0015 | 4 | — | — | — | — | — |
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| The current values above are based on actual tests of single strands of oxidized wire mounted in quiet air and operated at 1200°F. The tables are calculated for wire having a resistivity at 1200°F and a total surface watts-density of 28 W per square inch. |
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