How do you calculate awg

As you might guess, the rated ampacities are just a rule of thumb. In careful engineering the voltage drop, insulation temperature limit, thickness, thermal conductivity, and air convection and temperature should all be taken into account. The Maximum Amps for Power Transmission uses the circular mils per amp rule, which is very very conservative.

The Maximum Amps for Chassis Wiring is also a conservative rating, but is meant for wiring in air, and not in a bundle. For short lengths of wire, such as is used in battery packs you should trade off the resistance and load with size, weight, and flexibility. Contact your local electrician to find out what is legal! When high frequency AC is conducted by a wire there is a tendency for the current to flow along the outside of the wire.

This increases the effective resistance. The frequency listed in the table shows the frequency at which the calculated skin depth is equal to the radius of the wire, and is an indication that above this frequency you should start considering the skin effect when calculating the wire's resistance.

Breaking Force for Copper Wire This estimate is based on nick-free soft annealed Cu wire having a tensile strength of pounds per square inch. Note: It just calculates the voltage drop, consult the above table for rules-of-thumb, or your local or national electrical code or your electrician to decide what is legal!

Note that the voltage drop does not depend on the input voltage, just on the resistance of the wire and the load in amps. Trailer controllers, interface 12V and 24V vehicles and trailers. Precision Spot Welders. Wires can carry a certain amount of current continuously and no more; more current means the wire will overheat and melt as it cannot dissipate the heat that is generated by too much current flow. Certain factors reduce the ampacity rating of wires and the voltage drop as well:.

This is not an ABYC requirement at the moment; however, it is generally accepted by marine product manufacturers such as Blue Sea. Did we mention you actually don't need to use this calculator? It doesn't get easier than this! Here it is in action:. Always use the maximum current that the load is expected to draw. The Maxxfan can draw up to 2. As a result, you'll get slightly oversized wires which is quite good for safety, performance, and durability.

The wire length input is always the round-trip length. The round-trip length is the sum of the positive and the negative wires. Remember that a duplex wire packs the positive and the negative into a single wire, so the round-trip length is equal to twice the duplex length.

There is a loss of energy voltage drop as current moves through passive elements terminal, fuse, wire, etc. The easiest way to determine the fuse size is to follow the manufacturer recommendations!

So check the owner's manual or specifications sheet. Can't find it? OK then. In the Maxxfan scenario: 4A x 1. However, it looks like the manufacturer recommends a 10A, fuse so we'll stick to that. In the scenario where we have no clue how much current the Maxxfan draws load current , we'll use the fuse size instead.

Using our Google super skills, we find that the manufacturer recommends a 10A fuse:. This is to "compensate" for the slightly oversized wire that this method gives. Second — multiply the diameter by to find the area in kcmil or by 3. Also see our electricity cost calculator and our lighting cost calculator to before you plan your next electrical project.

You are here. Wire Diameter:. Wire Type:. Unfortunately, AWG does not fit comfortably in rounded mm or inches, so there will always need to be a small amount of rounding up or down depending on your need or purpose.

If you want the technical formulae for converting between the two, it is as follows;. The n gauge wire diameter dn in millimetres mm is equal to 0. Somehow we don't see ourselves nonchalantly calculating this in our heads every time we speak with an American customer, so we've made up a conversion table which we'd like to share for your convenience.

For AWG 23 and upwards - When using a cable to power mains voltages: v, v etc the smallest conductor we recommend is 0. For audio, video, telephone, security cabling you may want to use smaller cables sizes where the voltage and current are smaller.

Wire Gauges run low to high - this means that the smaller a gauge number, the larger it is in mm. Conversely, a large number in AWG equates to a very small number of mm. AWG sizes do not fit perfectly into mm or inches, so you may need to round up or down when safe to do so.