Ampacities of Wire Types (w/Temp Rating) @ 0-2000 Volts |
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|---|---|---|---|
Wire Size AWG |
TW, UF (140°) |
FEPW, RH, RHW, THW, THWN, ZW, THHW, XHHW (167°) |
USE-2, XHH, XHHW, -2, TA, TBS, SA, SIS, FEP, MI, RHW-2, THHN, ZW-2, THWN-2, FEPB, RHH, THHW, THW-2 |
| 0000 | 300 | 360 | 405 |
| 000 | 260 | 310 | 350 |
| 00 | 225 | 265 | 300 |
| 0 | 195 | 230 | 260 |
| 1 | 165 | 195 | 220 |
| 2 | 140 | 170 | 190 |
| 3 | 120 | 145 | 165 |
| 4 | 105 | 125 | 140 |
| 6 | 80 | 95 | 105 |
| 8 | 60 | 70 | 80 |
| 10 | 40 | 50 | 55 |
| 12 | 30 | 35 | 40 |
| 14 | 25 | 30 | 35 |
| 16 | - | - | 24 |
| 20 | - | - | 18 |
| Note: Type TW is the most common for house wiring. TW is for dry or wet conditions, and is covered in a single layer of plastic. |
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If the ambient temperature[1] is over 86°F(30°C), then the following corrections should be made by multiplying the above ampacities by the correction factor below: |
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Ambient[1] Ampacity Correction for (above) Wire Types |
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| Temp °F | 140 °F | 167 °F | 194 °F |
| 96-104 | 0.82 | 0.88 | 0.91 |
| 105-113 | 0.71 | 0.82 | 0.87 |
| 114-122 | 0.58 | 0.75 | 0.82 |
| 123-131 | 0.41 | 0.67 | 0.76 |
| 132-140 | - | 0.58 | 0.71 |
| 141-158 | - | 0.35 | 0.58 |
| 159-176 | - | - | 0.41 |
| [1] Ambient Temperature is the temperature of the material (air, earth, etc.) surrounding the wire. |
Ampacities of Wire Types (w/ Temp Rating) @ 0-2000 Volts |
|||
|---|---|---|---|
Wire Size AWG |
TW, UF (140°) |
FEPW, RH, RHW, THHW, ZW, THWN, XHHW, THW, USE (167°) |
USE-2, XHH, XHHW, -2, TA, TBS, SA, SIS, FEP, MI, RHW-2, THHN, ZW-2, THWN-2, FEPB, RHH, THHW, THW-2 |
| 0000 | 195 | 230 | 260 |
| 000 | 165 | 200 | 225 |
| 00 | 145 | 175 | 195 |
| 0 | 125 | 150 | 170 |
| 1 | 110 | 130 | 150 |
| 2 | 95 | 115 | 130 |
| 3 | 85 | 100 | 110 |
| 4 | 70 | 85 | 95 |
| 6 | 55 | 65 | 75 |
| 8 | 40 | 50 | 55 |
| 10 | 30 | 35 | 40 |
| 12 | 25 | 25 | 30 |
| 14 | 20 | 20 | 25 |
| 16 | - | - | 18 |
| 18 | - | - | 14 |
| Note: All notes that apply to single wire ambient temperature, also apply to this Three Wire section. Note: The information on this page was taken from the National Electrical Code ®, National Fire Protection Association, Quincy, Massachusetts 02269, © 1993 and does not represent the complete code. Note: In all Copper Wire Types listed above (except types: MI, TA, TBS, SA, SIS, RHW-2, THW-2, THWN-2, USE-2, XHH, XHHW-2, & ZW-2) overcurrent protection should not exceed 15 amps for 14 AWG, 20 amps for 12 AWG, and 30 amps for 10 AWG. This is not true if specifically permitted elsewhere in the Code. |