RV Trip Planning Discussions

Go Back   iRV2 Forums > THE OWNER'S CORNER FORUMS > Outdoors RV Owner's Forum
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
Reply
 
Thread Tools Search this Thread Display Modes
 
Old 09-17-2019, 07:38 AM   #1
Senior Member
 
Join Date: Dec 2018
Location: California
Posts: 134
Factory Solar Wiring

Just a preface of my thread. I bought my trailer, like many did with factory installed Solar Wiring. And like many, I had the dealer install 300w of panels and a controller into the factory wiring. And while it works adequately, I've never felt it really gets me to the full potential of the 300w available. At the time of the purchase I had no Solar Knowledge nor did I have the time to research and install my own setup due to my regular day job.....don't you hate when work gets in the way of what's important?.............I mean really?!!!!

So after taking a reading of 14.4v at the output side of the controller and then a reading of 13.91v at the batteries. Losing close to a 1/2 volt is not acceptable when you're only dealing with 12v. I have concluded that the #8 conductor from the factory is not really adequate. I suppose if you installed the Controller down close to the batteries and ran full Panel Array Voltage all the way down to the controller, it could be adequate. But the way the factory installed it It could be better. There is little if any effort made at the factory to keep the conductors as short as possible to minimize voltage loss. That #8 wire goes all the way to the right side of the trailer, then down the front, then back across to the left side of the trailer at the floor level, then it heads toward the back of the trailer to circle around and come into the J-box in the belly, through the 30a breaker and then to the batteries. That's a lot of wire on a wild ride sucking down voltage!

All this to say, I'm in the process of installing new #4 conductor in the most direct path from the soon to be newly installed combiner box to the new location for my controller as close to the batteries as possible. I'll use #2 wire to the batteries. I will have the option option of trying series or parallel type configurations once I get a new controller. Right now it will be parallel as my controller will not accept the kind of voltage series will produce. Assuming my new set up will produce a better charging voltage, I am pretty much in the camp that if you really want a great working solar system, you pretty much need to install it yourself.

I'll upload some picks when the project starts to take shape and it looks like I know what I'm doing!
__________________

__________________
V465
2015 Creek Side 20fq,300w Solar-Soon to be 450w
2013 GMC Denali, Duramax, Retiring in 2021
Vintage465 is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 09-17-2019, 09:45 AM   #2
Member
 
Join Date: Nov 2002
Location: Golden, CO
Posts: 54
Very interested in this. I have 900 watts and still using the factory wiring. My AGM batteries are in the front passthru. I already changed out the combiner box on the roof. I plan to run 4 awg from the combiner box to the controller located in the cabinet above the bed. That'll be easy, very short. Next I will continue down through one of the vertical cabinets on each side of the bed. The only possible challenge is the short section below this cabinet and above the bedside table/passthru storage.
__________________

LeisurePursuits is offline   Reply With Quote
Old 09-17-2019, 12:34 PM   #3
Senior Member
 
brulaz's Avatar
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Ontario Canada
Posts: 1,707
Think you guys have the right idea.
Factory wiring wasn't an option when we got ours.

Prolly just as well as we ended up going big.
__________________
2014 Timber Ridge 240RKS, 61K miles
690W Rooftop + 340W Portable Solar, 215Ah GC2s@24V
2016 Ram 2500 CTD 4x4 RegCab SLT, 10.4 mpgUS tow
brulaz is offline   Reply With Quote
Old 09-17-2019, 04:01 PM   #4
Senior Member
 
ModestMonk's Avatar
 
Outdoors RV Owners Club
Join Date: Oct 2016
Posts: 1,777
Well you can see a snapshot of the solar we have in our sig line. Our factory ready solar was terminal. The combiner box on the roof was installed poorly. All of the connections were loose, finger loose, like nuts started and never tightened. i have since recommended checking every connection and never assuming. Assume the liability by you or trust your installer with your lives.
__________________
2018 ORV 24KTS 26,000 +miles
2017 Ford 3.5 TwinTurbo w/MaxTow
640 Watts solar/600 Ahr PSoC Nano Carbon
ModestMonk is online now   Reply With Quote
Old 09-17-2019, 04:56 PM   #5
Member
 
jmltech's Avatar


 
Tiffin Owners Club
Join Date: Oct 2018
Posts: 32
Factory Solar Wiring

Since youíre taking the time and expense to run cable, I would run 2 gauge instead of 4. Youíll makeup some line loss, and it will allow additional panels or better panels if youíre upgrading. If your panels are in series/parallel combinations, then you probable donít have high amperage running down to the charger, in which 4 gauge may be good.
jmltech is offline   Reply With Quote
Old 09-17-2019, 07:36 PM   #6
Senior Member
 
Join Date: Dec 2018
Location: California
Posts: 134
Quote:
Originally Posted by LeisurePursuits View Post
Very interested in this. I have 900 watts and still using the factory wiring. My AGM batteries are in the front passthru. I already changed out the combiner box on the roof. I plan to run 4 awg from the combiner box to the controller located in the cabinet above the bed. That'll be easy, very short. Next I will continue down through one of the vertical cabinets on each side of the bed. The only possible challenge is the short section below this cabinet and above the bedside table/passthru storage.
What you're saying is what I've done. Except I'm yanking the controller from over the bed and putting it down by the batteries. The space between the night stand and the cabinet couldn't be sorted out. I had to run it in the corner. I'm making a piece of corner moulding to cover it. I have a sheet of the inside wall paneling and a roll of the matching tape. I will be working on that later this week and post pics of the completed product..............if I'm not too embarrassed of the outcome that is! I used 4awg Welding cable. Very flexible, super fine strand.
__________________
V465
2015 Creek Side 20fq,300w Solar-Soon to be 450w
2013 GMC Denali, Duramax, Retiring in 2021
Vintage465 is offline   Reply With Quote
Old 09-17-2019, 07:42 PM   #7
Senior Member
 
Join Date: Dec 2018
Location: California
Posts: 134
Quote:
Originally Posted by jmltech View Post
Since youíre taking the time and expense to run cable, I would run 2 gauge instead of 4. Youíll makeup some line loss, and it will allow additional panels or better panels if youíre upgrading. If your panels are in series/parallel combinations, then you probable donít have high amperage running down to the charger, in which 4 gauge may be good.
I probably should have gone with 2awg, but the voltage loss on a calculator was into the hundredths. The panels I have won't be replaced. Once I get the third one on, I'm out of real estate on the roof. I'll have 450w and the ability to run 18v in parallel with 24amp(best case scenario) or 54v in series with 8amps. So I think the 4awg will be fine............well, it has to be fine, I can't un-scramble that egg now!
__________________
V465
2015 Creek Side 20fq,300w Solar-Soon to be 450w
2013 GMC Denali, Duramax, Retiring in 2021
Vintage465 is offline   Reply With Quote
Old 09-17-2019, 08:47 PM   #8
Senior Member
 
Randy the sly old fox's Avatar
 
Outdoors RV Owners Club
Join Date: Oct 2003
Location: Hillsboro, OR, USA
Posts: 1,143
Before you actually wire the panels in series make sure the controller can handle it. Usually the PWM controllers can only handle 20V while MPPT controllers can often take up to 100V. Some of the MPPT controllers do not have panels and are programmed and read over a wireless ap on your smart phone.

I am considering at least 300 if not more watts and putting the controller out by the batteries. On my TT the wires run directly down the front behind the fiberglass cap to the box behind the A frame. I have heard that in units without the fiberglass caps have more wiring between the controller and the batteries.

I agree that losing even 1/2 V between the controller and the batteries is not good.
__________________
2017 Chevy 2500HD LTZ DuraMax Diesel Silver Ice Metallic
2017 Outdoors RV Timber Ridge 25RDS Mountain Series 4X Off Road Suspension Pkg
Randy the sly old fox is offline   Reply With Quote
Old 09-18-2019, 07:41 PM   #9
Senior Member
 
Join Date: Dec 2018
Location: California
Posts: 134
Quote:
Originally Posted by Randy the sly old fox View Post
Before you actually wire the panels in series make sure the controller can handle it. Usually the PWM controllers can only handle 20V while MPPT controllers can often take up to 100V. Some of the MPPT controllers do not have panels and are programmed and read over a wireless ap on your smart phone.

I am considering at least 300 if not more watts and putting the controller out by the batteries. On my TT the wires run directly down the front behind the fiberglass cap to the box behind the A frame. I have heard that in units without the fiberglass caps have more wiring between the controller and the batteries.

I agree that losing even 1/2 V between the controller and the batteries is not good.
My controller is good for 50v. Daisy chained Iíd have 54v on the best day. My plan for now is to move the controller close to the batteries and feed the controller 18v from parallel wiring. If that doesnít get me where I want to go then Iíll ďcontroller-upĒ to an mppt type unit and daisy chain them. And thatís correct about footage of wiring without a cap. Way to much.
Vintage465 is offline   Reply With Quote
Old 09-19-2019, 08:09 AM   #10
Member
 
Join Date: Nov 2002
Location: Golden, CO
Posts: 54
I don't think it works that way. You'll have 54 volts every day. That is constant. Your current (or amps) is what will vary.
LeisurePursuits is offline   Reply With Quote
Old 09-19-2019, 02:40 PM   #11
Senior Member
 
brulaz's Avatar
 
Outdoors RV Owners Club
Join Date: Dec 2014
Location: Ontario Canada
Posts: 1,707
Quote:
Originally Posted by LeisurePursuits View Post
I don't think it works that way. You'll have 54 volts every day. That is constant. Your current (or amps) is what will vary.

The V does vary. From the manual of my MPPT solar controller: "A typical day of operation for the MPT-3048, with a 24v nominal array and 12v nominal battery bank"
Attached Thumbnails
Click image for larger version

Name:	temp.jpg
Views:	16
Size:	126.3 KB
ID:	260894  
__________________
2014 Timber Ridge 240RKS, 61K miles
690W Rooftop + 340W Portable Solar, 215Ah GC2s@24V
2016 Ram 2500 CTD 4x4 RegCab SLT, 10.4 mpgUS tow
brulaz is offline   Reply With Quote
Old 09-19-2019, 09:40 PM   #12
Senior Member
 
Randy the sly old fox's Avatar
 
Outdoors RV Owners Club
Join Date: Oct 2003
Location: Hillsboro, OR, USA
Posts: 1,143
OK Actually both will vary - however for the most part a solar cell is a constant current source - until a point where it knees over and drops to zero. Panels are rated at no load voltage - usually around 20V and at the maximum current draw into a near short at zero volts. Power on the other hand will gradually rise from the zero volts to the knee point then drop off. So the amount of sunshine determines the current and voltage. If you are familiar with diode and transistor curves the solar cells look similar but in reverse - the curves end at Vmax I min instead of starting at Vmin and I max. The sunshine is like the base drive.

MPPT devices adjust their load resistance to always track the knee where the peak power resides.
__________________
2017 Chevy 2500HD LTZ DuraMax Diesel Silver Ice Metallic
2017 Outdoors RV Timber Ridge 25RDS Mountain Series 4X Off Road Suspension Pkg
Randy the sly old fox is offline   Reply With Quote
Old 09-23-2019, 04:14 PM   #13
Member
 
Join Date: Nov 2002
Location: Golden, CO
Posts: 54
I was able to get the cable from the roof to the passthru today. I went with 6 AWG which will be plenty for the number of amps that I will actually see in the "real world". A tiny voltage drop between the panels and the MPPT controller is no big deal. It is also the max wire gauge for my Victron MPPT 150/50. It was a bit of a tight squeeze getting it through that area next to the side of the bed, above the counter and below the wardrobe. I have an AC outlet in that space which I took out so I could get a small mirror in there to see what I was working with. I need to finalize my wiring in the next couple days and then I will post some pictures.

ETA, I liked the idea of moving the controller to down next to the batteries so I am doing that.
LeisurePursuits is offline   Reply With Quote
Old 09-29-2019, 10:36 AM   #14
Member
 
Join Date: Nov 2002
Location: Golden, CO
Posts: 54
Here are a few pictures of how I routed the 6 gauge cable.





__________________

LeisurePursuits is offline   Reply With Quote
Reply

Tags
solar, wiring



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Factory Solar wiring issue mrgrayaz 5th Wheel Discussion 7 09-12-2017 05:47 AM
Factory Solar Wiring Kend51 Newmar Owner's Forum 10 03-11-2015 06:57 AM
Solar Panel Factory Wiring JAW Monaco Owner's Forum 3 12-28-2014 10:17 AM
Factory order stuck at factory? WineLuvrs Winnebago Industries Owner's Forum 28 07-13-2013 08:42 PM
Windstar 7000 non factory tow vs. 8500 factory tow option. Hammond Pop Up, Tent Trailer and Teardrop Topics 1 01-30-2008 06:03 PM

» Featured Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 03:19 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×