Get our free book (in Spanish or English) on rainwater now - To Catch the Rain.

# Difference between revisions of "Wire length tables"

## Introduction

Describe wire length, voltage loss, etc. here.

## Tables

The following table shows the American Wire Gauge (AWG) size for several different round trip (RT) wire lengths based on maximum current (A) for a 12V DC system (assuming 3% maximum wire loss):

Table 1. Wire Sizes
RT length 5A 10A 15A 20A 25A 30A 40A 50A
15 ft 16 12 10 10 8 8 6 6
20 ft 14 12 10 8 8 6 6 4
25 ft 14 10 8 8 6 6 4 4
30 ft 12 10 8 6 6 4 4 2
40 ft 12 8 6 6 4 4 2 2
50 ft 10 8 6 4 4 2 2 1
60 ft 10 6 4 4 2 2 1 1/0
70 ft 8 6 4 2 2 2 1/0 2/0
80 ft 8 6 4 2 2 1 1/0 2/0
90 ft 8 4 2 2 1 1/0 2/0 3/0

This table was adapted from Engineering Toolbox [1] .

## Calculating Wire Sizes

1. copper wire resistivity = 11.2 [2]
2. 3% loss from wires
3. allowable voltage drop = 0.36V
• 12V system, 3% (0.03) wire loss -> 12V x 0.03 = 0.36V

Variable Declarations:

• An: circular mil area
• n: AWG
• m: AWG
• Conductor resistivity: constant, 11.2
• Current: current through wire in Amps, acquired from table
• Roundtrip (RT) wire length: complete length of wire, ft, acquired from table
• Allowable voltage drop: voltage drop through wires, V
 Table 2. Calculating Wire Sizes Equation Step # Step 1 : The equation to the left (Eqn. 1) was used, rearranged, and iterated on to produce Table 1. [3]. Step 2 : Algebraically rearrange Eqn. 1 to solve for n. The resulting equation is Eqn. 2 to the left. Step 3 : If n<0, replace n with 1-m in Eqn. 1 [4] . Step 4 : File:3 wireloss.png 180x180px|5 Step Solve Eqn. 3 for m, the resulting equation (Eqn. 4) is to the left. : File:4 wireloss.png

See Help:Tables.

Use help:references to see how to use the reference format.[1]

Use Help:Images on how to upload the graph image(s). Please remember to use a very descriptive name for the file.

## References

1. It is quite easy and just relies on ref and /ref in between less than and greater than symbols.