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DC Wiring Chart


The chart is calculated on no more than 2% voltage drop across the wire distance.

The distance is twice your length.  If you are running a 2’ cable then your distance for the chart is 4’.  This accounts for the round trip distance of the run. 

Maximum length of wire

2’

4’

6’

8’

10’

12’

14’

16’

20’

24’

28’

Amps

 

 

 

 

 

 

 

 

 

 

 

3 Volt System

 

 

 

 

 

 

 

 

 

 

 

1 amps or less

22 ga

22 ga

20 ga

18 ga

18 ga

16 ga

16 ga

14 ga

14 ga

14 ga

12 ga

3 amps or less

20 ga

16 ga

14 ga

14 ga

12 ga

12 ga

 

 

 

 

 

5 amps

18 ga

14 ga

12 ga

12 ga

10 ga

10 ga

10 ga

10 ga

8 ga

8 ga

6 ga

10 amps

14 ga

12 ga

10 ga

8 ga

 

 

 

 

 

 

 

6 Volt System

 

 

 

 

 

 

 

 

 

 

 

Up to 5 amps

20 ga

18 ga

16 ga

14 ga

14 ga

12 ga

12 ga

12 ga

10 ga

10 ga

 

10 amps

16 ga

14 ga

12 ga

12 ga

10 ga

10 ga

8 ga

 

 

 

 

15 amps

16 ga

12 ga

10 ga

10 ga

8 ga

 

 

 

 

 

 

12 Volt System

 

 

 

 

 

 

 

 

 

 

 

Up to 5 amps

22 ga

20 ga

18 ga

16 ga

16 ga

16 ga

14 ga

14 ga

12 ga

12 ga

12 ga

10 amps

18 ga

16 ga

16 ga

14 ga

14 ga

12 ga

12 ga

12 ga

10 ga

10 ga

8 ga

15 amps

18 ga

16 ga

14 ga

12 ga

12 ga

10 ga

10 ga

10 ga

8 ga

8 ga

 

24 Volt System

 

 

 

 

 

 

 

 

 

 

 

Up to 5 amps

22 ga

22 ga

22 ga

20 ga

20 ga

18 ga

 18 ga

16 ga

16 ga

16 ga

14 ga

10 amps

22 ga

20 ga

18 ga

18 ga

16 ga

16 ga

14 ga

14 ga

14 ga

12 ga

12 ga

15 amps

20 ga

18 ga

16 ga

16 ga

14 ga

14 ga

12 ga

12 ga

12 ga

10 ga

 10 ga

This chart was not prepared by an electrical engineer.  The chart is conservative but teams should use this only as a general guide.  It is always OK to use a larger wire size.  The only consideration when using larger wire is the difficulty in handling the wire.

In places where the chart is not complete the wire sizes are getting to too large to be realistically worked with

Very low voltages are very difficult to send over long stretches of wire.  You have a problem with the voltage dropping significantly over longer runs of wire.  This is why the suggested wire gauge is very heavy for longer runs at 3Volts.  In these cases you may be better off with the power source where you need the power.

 If you know the voltage and current draw of devices you are wiring you can calculate the appropriate wire size.  You can find wire size calculators on the web at:

http://www.powerstream.com/Wire_Size.htm

http://www.menninga.com/voltcalc.htm - for DC Voltage select single phase under “phase of circuit”
(you may have to install a Java Plug In for your Browser to use this calculator)

Voltage Drop Calculator:  http://nooutage.com/vdrop.htm