For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities specified in Table E3705.1 by the appropriate correction factor shown in Table E3705.2.
TABLE E3705.2
AMBIENT TEMPERATURE CORRECTION FACTORS
| For ambient temperatures other than 30°C (86°F), multiply the allowable ampacities specified in the ampacity tables by the appropriate correction factor shown below. | ||||
| Ambient Temperature (°C) | Temperature Rating of Conductor | Ambient Temperature (°F) | ||
| 60°C | 75°C | 90°C | ||
| 10 or less | 1.29 | 1.20 | 1.15 | 50 or less |
| 11-15 | 1.22 | 1.15 | 1.12 | 51-59 |
| 16-20 | 1.15 | 1.11 | 1.08 | 60-68 |
| 21-25 | 1.08 | 1.05 | 1.04 | 69-77 |
| 26-30 | 1.00 | 1.00 | 1.00 | 78-86 |
| 31-35 | 0.91 | 0.94 | 0.96 | 87-95 |
| 36-40 | 0.82 | 0.88 | 0.91 | 96-104 |
| 41-45 | 0.71 | 0.82 | 0.87 | 105-113 |
| 46-50 | 0.58 | 0.75 | 0.82 | 114-122 |
| 51-55 | 0.41 | 0.67 | 0.76 | 123-131 |
| 56-60 | — | 0.58 | 0.71 | 132-140 |
| 61-65 | — | 0.47 | 0.65 | 141-149 |
| 66-70 | — | 0.33 | 0.58 | 150-158 |
| 71-75 | — | — | 0.50 | 159-167 |
| 76-80 | — | — | 0.41 | 168-176 |
| 81-85 | — | — | 0.29 | 177-185 |
For SI: 1 °C = [(°F) - 32]/1.8.