Oncered: Newbie 250 Watt system install questions

Welcome to the form Oncered,

I moved to your own thread... Usually it keeps "discussions" a bit easier to follow--This thread is "yours"--So ask the questions you need to ask.

I suggest that you ask a few (related) questions at a time. Asking 20 Questions at once really can get confusing when folks answer different pieces.

So continue on here.

-Bill

Yes, you can use automotive crimp connectors... Just seal them from weather (J-box, tape, etc.). There are lots of other options too... One is to use "bus bars" in plastic J-boxes). You want rugged/reliable/safe connections--Solar power can be a bit more "difficult" than AC circuits--Solar runs near maximum rated current for hours per day on hot roofs... Most people only run their AC applanices and wiring at much less than "rated" capacity (erroring on "oversizing" wire gauge is not bad :

http://www.solar-electric.com/installation-parts-and-equipment/midnite/brbusbatebus.html bus bars
http://www.solar-electric.com/catalogsearch/result/?q=distribution+panle&cat=0 Insulated power distribution blocks

Poster 2manytoys has documented his many years of evolving solar power system design/installation--Including a lot of DIY type projects:

http://2manytoyz.com/ (solar is ~2/3rds way down on the right side of the page)

Are you using 2x 125 Watt panels in parallel? Length of wiring and current determine the actual AWG of wire needed... You can use a voltage drop calculator and figure out the "optimum" wire size (typically 1-3% voltage loss for wiring is common in solar):

http://www.calculator.net/voltage-drop-calculator.html

A few wires/stacked ring lugs is typical... But as you grow the system, it is better to use bus bars and distribution panels. Every + wire that leaves a bus bar should have its own breaker/fuse (i.e., 14 AWG wire should have ~15 amp fuse/breaker). If you have lots of DC (and AC) connections, you should look at true breaker/distribution panels:

http://www.solar-electric.com/installation-parts-and-equipment/midnite/elenanddcdi.html

If you are paralleling batteries for your bank, see here:

http://www.solar-electric.com/batteries-meters-accessories/bach2/me-sbc.html

For your RV wiring... You need to define loads and charging current--Then design the wiring/fusing/breakers to support those expected current flow. The Original RV wiring probably supported a few lights, fan and a few other loads. Your are adding to the overall system now (I guess).

-Bill