Matching Wire Size to Circuit Amperage

Wire is sized by the American Wire Gauge (AWG) system. Wire gauge refers the physical size of the wire, rated with a numerical designation that runs opposite to the diameter of the conductors—in other words, the smaller the wire gauge number, the larger the wire diameter. Common sizes include 14-, 12-, 10-, 8-, 6-, and 2-gauge wire.

Basic wire sizing guide for US 120 and 240 volts. Added by: snoofer . Useful info: # = American Wire Gauge (AWG), the lower the number the larger the wire guage. "Service cable" is large insulated stranded copper cable (usually refers to single #4 wire and up).

As the wire size amp rating chart at Cerrowire states, under normal household temperature conditions, the maximum current rating for a 14-gauge wire is 15 amps, while that for a 12-gauge wire is 20 amps. It's OK to wire a 15-amp light circuit with a 14-gauge wire to save a bit of money and make the wiring job a bit easier.

If you can't strip the jacket, use the "14 gauge" jaws. Using the 12 gauge jaws of the tool significantly decreases the chance of nicking the wire. When using the 14 gauge jaws, hold the tool at a right angle to the wire, otherwise you will damage the wire. Also strip the end of the ground wire if it is insulated. If you cut too deep, don't ...

Wire gauge calculations Wire diameter calculations. The n gauge wire diameter d n in inches (in) is equal to 0.005in times 92 raised to the power of 36 minus gauge number n, divided by 39:. d n (in) = 0.005 in × 92 (36-n)/39. The n gauge wire diameter d n in millimeters (mm) is equal to 0.127mm times 92 raised to the power of 36 minus gauge number n, divided by 39:

For the 00, 000, 0000 etc. gauges you use -1, -2, -3, which makes more sense mathematically than "double nought." This means that in American wire gage every 6 gauge decrease gives a doubling of the wire diameter, and every 3 gauge decrease doubles the wire cross sectional area. Similar to dB in signal and power levels.

Quality marine wire, as specified by ABYC standards, will always be stranded rather than solid, and always tin-plated copper. In addition, the DC Wire Selection Chart shown below assumes a wire insulation rating of 105°C. A lower rating will decrease the current-carrying capacity of the wire.

Typically most automotive systems run at 13.8V, but you can select 6, 12, 13.8 (Default) or 24 volts. If the wire gauge is OK to use it will have a 'Check Mark' on the same line. The 'Max Length' indicates the maximum length of wire of that gauge that can be use at the given values you entered.

– The calculator allows entry of a voltage drop, but caution should be used when doing so to make sure you are calculating the wire sizes in accordance with NEC article 210-19 (FPN No. 4.) The NEC allows a maximum of a 3% voltage drop on the main branch of a circuit at the farthest outlet of power and 5% total to both feeders and branch circuits to the farthest outlet.

What Gauge AWG Wire to Use for Solar Electric Systems. Includes 12, 24, and 120-volt charts and a metric to AWG size conversion table. This is a five percent table which means at these amperage ratings at the listed distances, 5% of the power would be lost to resistance. Five percent is normally acceptable in low voltage systems, but if you want a 2% figure, divide the given distances by 2.5.