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Topic: appx lenght of 10awg wire for factory solar in a 99 midbath? (Read 255 times) previous topic - next topic
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appx lenght of 10awg wire for factory solar in a 99 midbath?
I've read several people mention the "10awg wire" for the factory installs, it looks like it takes quite a detour path going to the controller in the upper cabinet, and back to the bank. not being able to see behind the scenes, does anyone happen to know the appx total run is?
1999 MB
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #1 –
Sorry, no help here, in my experience it is about 6” longer than whatever you cut, so I start with 50’ then cut it when I install it, usually either 3’ too long, or 3” too short.  As I keep cutting it, it doesn’t get any longer. 

Good luck.
Paul
'92 Mid Bath
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #2 –
haha, i was more wondering for a loss/capacity point of view... it just looks like a longer than necessary path, but i'm also not ambitious enough right now to rewire or relocate the controller, so i'm wondering what capacity is really there. wire size is half of the info.
1999 MB
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #3 –
The resistance of 10 gauge wire is 1.1 Ohms per 1000'. So, if you have a 20' run, positive and negative (i.e. 40'), then the total resistance would be 0.044 Ohms. If the panel output is 10 Amps, you would have a net voltage drop of about 0.4 Volts. Less than pristine connectors or splices in the loop could add another volt drop. So I wouldn't worry too much about the length of the run and concentrate on the best and most durable connections at each node.

Steve
2004 FL
2013 Honda Fit
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #4 –
so, that's what i was getting at i think... not knowing how long that run is, makes it harder for me to tell if i'm staying in the 3% drop rule of thumb. .4V is 4%, so it would seem like like the ideal amount of extra panels for my factory wiring would probably be somewhere below the 27-30a capacity of my controller? pending i had great connections?

just based on the wall dimensions, i'm wagging 2' of roof travel, 7' of vertical drop, and as much as 14' of horizontal back and forth to go from the fridge area to the controller and back again... so 20-23'?

BTW, looking more, i think i've seen just as many messages stating that they believe the factory wiring is 12AWG, so i'm not particularly sure about that either.

am i guessing this correctly below? or do i need to use 18V numbers, which are probably better, but aren't provided?
1999 MB
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #5 –
Every LD solar panel lead in wires, that I have worked on, had 10-gauge wiring.
This is fine for up to 200-watts of panels but inadequate for bigger arrays.
The one place you don't want to cut corners is on the primary charging wiring, be it either charging from the solar panels or the converter.
When designing and installing solar systems, I prefer to keep the voltage drop in the 1-2% range, for best efficiency.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #6 –
Depends on your Goal.
I had an '88 MB plugged into the house.  My goal was to get the LD off the Power bill and run the thermostatically controlled Fantastic Fan when needed.
There is a #6 wire from the converter to the Battery, with a CB at the battery end.  I used #10 from the Solar Panel Y connector to the PWM Charge Controller with 30 amp fuses on both ends of the positive wire.  Used #10 from the Controller to the Converter, with 30 amp Fuses on both ends of the Positive wire. Cost was $600.00 in material for 200 Wattts.
My operating current is typically less than 3 amps.   3amp x .044 Ohms = 0.132 volts. 

The bigger issue was in the "San Jose Heat Week 2017," my youngest slept in the LD and ran the Fantastic Fan, the swamp cooler fan and personal fan at 10 amps day and night.  With only 200 watts of solar the 200 Ahr battery was at 11.2 Volts in 3 days.  The CO detector woke me in the house at 3 am on the third night.  Obviously I need more umph if this continues.

If you are sitting in the same location  un plugged for more than a day you will want to follow the 2% rule, so Run #6 wire.  I tend to move every 2 days, so the truck generator will recharge the coach battery.
Rodney
1988 Mid Bath
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #7 –

Wire capacity chart, base on wire length and amperage load .
Marine Wire Size and Ampacity | West Marine

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #8 –
Larry is using a color-coded wire chart. Hmmm...

Anyway, his wiring advice is what to follow if your intent is to add more panels, and I would recommend also replacing the factory charge controller with one that is truly multi-stage. Also replacing the converter with a multi-stage battery charging one will allow properly bringing the batteries back to full with minimum connection time on shore-power.

Steve
2004 FL
2013 Honda Fit
Re: appx lenght of 10awg wire for factory solar in a 99 midbath?
Reply #9 –
ok, 10 amps is about where my interpolation puts me from the blue sky table at my 20' one way guess. i'm thinking they could have halved the drop by putting the controller somewhere closer to the direct path, but oh well.

too bad i don't want to fork out for a remote display, nor do i like to re-wire.
1999 MB