Count the number of strands. Multiply the wires diameter by itself.
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How to determine automotive wire gauge. Count the individual strands of copper. Most wire strippers have a series of round holes labeled with awg sizes where you can insert the wires. Enter these two figures in the calculator and youll get the cable area in sq. Over 16 feet with 3 voltage drop a 50 amp circuit requires 4 gauge power wire. In general the larger the current draw the larger gauge wire you need to properly power the accessory. Use a micrometer to measure one of the strands.
American wire gauge awg is a system of numerical wire sizes that start with the lowest numbers 60 for the largest sizes. For our example we are going with 16 feet. Awg is also known as brown sharpe gage. The result will be 0000025 in 0000635 mm. The gauge sizes are each 26 apart based on the cross sectional area. To calculate the gauge of stranded wire youll need to double the diameter.
Outside engine compartments the ambient temperature should generally be 20c. The gauge you need depends on the current draw of the accessory and the wire length between the accessory and the power source. So if youve measured a wires diameter to be 0005 inches 0127 mm multiply this value by itself. The n gauge wire diameter d n in millimeters mm is equal to 0127mm times 92 raised to the power of 36 minus gauge number n divided by 39. Compare the number of strands and the size of the strand to the chart below to determine the gauge. Swg standard or sterling wire gauge a british wire measurement system.
You can use a common wire stripper however to determine the diameter or the gauge size of the wires. How to determine the gauge of your automotive wire make a 12 cut in the wire. Wire size is measured by gaugethe smaller the gauge number the larger the wire. Dn in 0005 in 92 36 n39. To determine how big the wire needs to be you have to figure the approximate length of the wire from the amp installation point to the battery all amps must be wired directly to the battery. You not only can strip wires of a specific size but can also determine the gauge size of the wire.
Measure the diameter of a single strand not the whole bundle of strands which make up the cable or get this information from the cable suppliers website. Choosing the correct gauge automotive wire depends on the acceptable voltage drop length of the feederbranch circuit conductor load amperage and the ambient temperature of the compartment where the primary wire will pass through.
Gallery of How To Determine Automotive Wire Gauge
