Date:         Tue, 19 Jun 2007 14:11:58 -0500
Reply-To:     Matt Roberds <mattroberds@COX.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Matt Roberds <mattroberds@COX.NET>
Subject:      Re: Wire Gauges for Solar panels for your Vanagon
Comments: cc: David Etter <detter@MAIL.AURACOM.COM>
In-Reply-To:  <20070619152452.GNOC28013.fed1rmmtai111.cox.net@fed1rmimpi04.cox.net>
Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed

> From:    David Etter <detter@MAIL.AURACOM.COM>
> Date:    Tue, 19 Jun 2007 10:37:53 -0300
>
> The chart below was taken from a booklet put out by 'SURE POWER
> INDUSTRIES"

Note that this appears to be the voltage drop for one way - in other
words, for a system like a car where the body acts as one conductor and
is assumed to have a very low resistance relative to the supply wire.
For a solar panel system, you need to double the length, because you're
using wire for both conductors.  In other words, if you have a solar
panel that puts out 12 V, and you want to put it on the end of 10 feet
of two-wire cable, you need to look up the value under "20 feet" in the
tables.

Reformatted for readability:

> The charts on these pages show wire sizes for both a 10% voltage
> drop (most normal accessories) and a 3% voltage drop (sensitive
> electronics).
>
> WIRE GAUGE for 10% Voltage Drop 12 Volt Systems (AWG)
>
>                Wire to load in Feet
>                10  15  20  25  30  35  40  45  50
>              ------------------------------------
> Current   5  | 14  14  14  14  14  14  14  14  12
> (amps)   10  | 14  14  14  12  12  12  10  10  10
>          15  | 14  14  12  10  10  10   8   8   8
>          20  | 12  12  10  10   8   8   8   6   6
>          25  | 10  10  10   8   8   8   6   6   6
>
>
> WIRE GAUGE For 3% Voltage Drop 12 Volt Systems (AWG)
>
>                Wire to load in Feet
>                10  15  20  25  30  35  40  45  50
>              ------------------------------------
>        5     | 14  12  12  10  10   8   8   8   8
>        10    | 12  10   8   8   6   6   6   4   4
>        15    | 10   8   6   6   4   4   4   4   2
>        20    |  8   6   6   4   4   2   2   2   2
>        25    |  8   6   4   4   2   2   2   1   1

Matt Roberds