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eheffa · 10-21-2009, 05:47 PM

Hi all,

I am trying to put together a Solar Charging System for our unit & am wondering about some of the practical issues of wiring.

I have looked at the schematics of the Solar Prewire package I supposedly have in the unit ( I have checked & the Green / yellow bundle is there in the Reefer compartment) & it looks like I may not have to do a lot of wire pulling to get from the roof to the battery buses but I see that it is 10 g wire they have installed. I was thinking I would go for a two panel 200 watt system from AM Solar. They include 8 ga wire for their system but I wonder whether the 10 ga factory stuff would be adequate.

I will obviously have to ask Roger at AM Solar but I'm curious to know whether anyone else here has been down this road ahead of me & could share some of their experience?

As a secondary question: Where did you install your control panel?

Thanks in advance.
-evan

Ag&Au · 10-21-2009, 08:37 PM

It should work fine at the wire lengths in a travel trailer.
25 feet of #10 stranded wire will have a voltage drop of .43 volts at the ~17 amp max current of a 200 watt array. this is a loss of ~7 watts or 3.5%. With number 8 wire the loss will be about 4.7 watts or 2.4%.
You will never now the difference.
Regards,
Ken
P.S. The 7 watts is the power warming the wire, so it will not noticeably warm

eheffa · 10-21-2009, 10:23 PM

Hmmm,

AM Solar recommends the 8AWG but using your numbers the difference in power would only be about 2.3 watts of power loss at full charging capacity. I assuem that a lot of the time the current prodeuced by the panels would be a lot less than that (under less bright conditions etc.... I wonder whether anyone has measured how much voltage drop there is across the respective installations?

I don't want to cut corners but it seems a shame to not use the already installed 10AWG if the time & trouble of fishing a new 8 AWG line would only have marginal benefit....

Hmmm

Thanks for the feedback.

-evan