Based on the 2017 N.E.C. National Electrical Code.
Ampacity is the maximum continuous current carrying capacity of a wire inside a cable or raceway. It is measured in amperes (amps). The proper amperage is determined by the size of the wire, ambient temperature, number of wires installed together, the types and number of electrical devices connected on a circuit. It is different for copper wire than Aluminum wire.
The proper wire size must be selected in order to meet the load requirements of you application. There is an additional de-rating adjustment factor that needs to be taken into account for selecting the correct wire size. The following table if offered for informational purposes only.
Wire & Cable installation can be very dangerous. Please consult a licensed electrician, the latest version of the N.E.C. National Electrical Code and your local municipal inspector for guidance on selecting and installing the proper wire for your application.
Amp Copper | Amp Aluminum | ||||
---|---|---|---|---|---|
Wire Size | 60°C (140°F) | 75°C (167°F) | 90°C (194°F) | 75°C (167°F) | 90°C (194°F) |
14 AWG | 15 | 20 | 25 | - | - |
12 AWG | 20 | 25 | 30 | 20 | 25 |
10 AWG | 30 | 35 | 40 | 30 | 35 |
8 AWG | 40 | 50 | 55 | 40 | 45 |
6 AWG | 55 | 65 | 75 | 50 | 55 |
4 AWG | 70 | 85 | 95 | 65 | 75 |
3 AWG | 85 | 100 | 115 | 75 | 85 |
2 AWG | 95 | 115 | 130 | 90 | 100 |
1 AWG | - | 130 | 145 | 100 | 115 |
1/0 | - | 150 | 170 | 120 | 135 |
2/0 | - | 175 | 195 | 135 | 150 |
3/0 | - | 200 | 225 | 155 | 175 |
4/0 | - | 230 | 260 | 180 | 205 |
250 MCM | - | 255 | 290 | 205 | 230 |
300 MCM | - | 285 | 320 | 230 | 260 |
350 MCM | - | 310 | 350 | 250 | 280 |
500 MCM | - | 380 | 430 | 310 | 350 |
600 MCM | - | 420 | 475 | 340 | 385 |
750 MCM | - | 475 | 535 | 385 | 435 |
1000 MCM | - | 545 | 615 | 445 | 500 |
* This table is offered for informational purposes only.
* Wire & Cable installation can be dangerous and hazardous. Please consult a licensed electrical professional for proper selection and installation.