Question: How do you determine what wire gauge to use if you will carry 100 amps over 6 Feet and require a voltage drop of less than 0.1Volts?

Answer: There are tables and calculators, available on the internet that will determine the appropriate wire gauge for your application. To search for wire gauge ampere rating tables usekeywords such as AWG, Wire Ampacity, and Wire Manufacturers, these keywords will help you find Tables and Free Calculators that will make it easy to determine the appropriate wire gauge and wire type for your application. Also using an American Wire Gauge (AWG) Table and a simple formula below will also help you select the correct wire gauge.

Voltage Drop / Maximum Current = Wire Ohms per total length of cable(example: 0.1Vdc/100A = 0.001 Ohm)

Since the length of wire in the example is 6 feet you must convert the resistance of the wire in
Ohms per 1000 feet.

(0.001, / 6 feet) * 1000 feet = 0.1666 Ohm, per 1000 feet

Looking in the table below the appropriate wire gauge would be a 2 gauge wire.

There are other factors such as Insulation type and Temperature rating and Single wires versusbundled wires that can effect your selection. These are covered in each manufacturers’ websites and catalogs.

 

example table

Example Table

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