Description

This article is from the Car Audio FAQ, by Ian D. Bjorhovde (ianbjor@mobileaudio.com) with numerous contributions by others.

2.3 What is the best power wire to use? [JSC]

There is much debate over the benefit of certain wiring schemes
(oxygen-free, multistranded, braided, twisted, air core, you name it).
However, most people do agree that the most important factor in
selecting power wire is to use the proper size. Wire is generally
rated in size by American Wire Gauge, abbreviated AWG, or commonly just
"gauge". To determine the correct wire size for your application, you
should first determine the maximum current flow through the cable
(looking at the amplifier's fuse is a relatively simple and conservative
way to do this). Then determine the length of the cable that your will
use, and consult the following chart, taken from the IASCA handbook
(see Section 6.1),

                               Length of run (in feet)
     Current     0-4  4-7 7-10  10-13  13-16  16-19  19-22  22-28
  
        0-20A     14   12   12     10     10      8      8      8
       20-35A     12   10    8      8      6      6      6      4
       35-50A     10    8    8      6      6      4      4      4
       50-65A      8    8    6      4      4      4      4      2
       65-85A      6    6    4      4      2      2      2      0
      85-105A      6    6    4      2      2      2      2      0
     105-125A      4    4    4      2      2      0      0      0
     125-150A      2    2    2      2      0      0      0     00

If aluminum wire is used instead of copper wire, the next larger size
(smaller number) should be used. You should also consider the
installation demands: will you need to run the wire around corners or
through doors or into the engine compartment? These sorts of problems
in the car audio application require some special care in cable
selection. You will want to have cable that is flexible; it should
have thick insulation as well, and not melt at low temperatures. You
don't want to install wire that is rigid and prone to cracks and cuts,
or else the results could literally be explosive.

 

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