Solar wiring from roof?

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Rob&Deryl

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Mar 27, 2017
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1,206
Location
Eastern Massachusetts
We start our rv adventure in April. Will be close to home (New England) for at least the first 4 months.

I have visions of someday getting to Kofa, Canyon lands and other spectacular boon docking places.

While I have learned quite a bit about residential solar since I want it at the next house, I am a novice at rv solar.

My trailer has lots of room for batteries up to several hundred additional pounds. I will know more when I weight it on the way home when we pick it up in April.

I see pictures of RVs that are used by serious boondockers. 6 or more panels on the roof. I don?t expect to get that many but certainly several on the roof is within my imagination.

I am sure I can handle fastening down the panels since there have been lots of discussion on the topic here.

What I have no clue about is getting wire (solar, radio, tv etc) into the rv without bringing lots of weather products as well.

Educate me? Oh, I guess charge control and inverters too though we could split those out to a new thread.

Thank you. I never would have pulled the trigger on this without the education I get here.
 
B

Boat Addict

Guest
Well I am not an expert, but I read a lot and talked to a lot of folks for my simple set up.  It used to be that you needed a number of panels to do the same that fewer ones will do now. Wattage for a single panel  have increased over the past few years and is improving like most technical advances in cell phones do several times a year now. 

There are also better panels if you are willing pay the price that actually stick to the top of your camper, which also saves weight and a bunch of holes in the roof.  I did not go that direction.  As it relates to wires leading back into my camper, well there are "Y" connectors that combines one or more  panels positive and negative cables allowing you to only need to run two main wires back into the camper.  For me I choose like wattage panels , which is stated to improve performance.

And for me I installed my panels forward on my roof and was able to take advantage of my forward bedroom overhead cabinets to run my wires thru drilled holes at the top of my sides and into the cabinet and down to the needed controller. I wanted to minimize additional holes in the roof even though the framed panels that I used required them. But the brackets that my panels fit in are wide enough with quality caulking under them , they bedded nicely and securely coupled with  rubber grommets under the hex head screws.
So that's a starting point.
 

Mark_K5LXP

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Nov 17, 2018
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1,158
Location
Albuquerque, NM
You can make or buy a utility box that you fasten to the roof, then make your roof permeation through the box.  That way you have two sealing points for the wires - where they enter the box and between the box and the roof.  Having the box also gives you a weathertight place to make connections to your panels via bus bars or connectors.

Mark B.
Albuquerque, NM
 

Gary RV_Wizard

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Feb 2, 2005
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At our Silver Springs FL home
A common trick is to route wires down through the chimney for an RV fridge. That gets it through the roof and from there you can route sideways to the interior or further down underneath. Obviously the location of the fridge vs the battery is a key factor with this method. 

Another is to route through the front or rear cap fiberglass, if there is one (in a trailer there may not be a cap over the wall structure - the wall itself is the outer skin). The cap is just a shell and provides a place to hide wires while routing them down to the underside, where you then get to the battery location. May be a long wire run, though.

Short of those possibilities, you need to make a hole in the roof somewhere and Mark's utility box suggestion is the best way to handle that. Of course you have to put the hole someplace where you can get through the interior without wires dangling from the kitchen ceiling.  ???
 
B

Boat Addict

Guest
Gary RV_Wizard said:
A common trick is to route wires down through the chimney for an RV fridge. That gets it through the roof and from there you can route sideways to the interior or further down underneath. Obviously the location of the fridge vs the battery is a key factor with this method. 

Another is to route through the front or rear cap fiberglass. The caps are just a shell, though in a trailer there may not be a cap over the wall structure.

Short of those possibilities, you need to make a hole in the roof somewhere and Mark's utility box suggestion is the best way to handle that.

A point of note dealing with running wires thru the roofs these days,, With the newer campers the roofs are crowned and can also have a void between the outside and inside ceiling. The newer ones also have vented duct work in the ceiling for the ac units. So be mindful of your location when you drill down in the roof. And keep in mind the wiring and fixtures  for the overhead lights when drilling into the roof when using a master junction box to run wires down. 
 

Kevin Means

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Aug 3, 2010
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Lakeside, California
We work with installers from all over the country, and when multiple panels are installed, a rooftop junction box is almost always used. Some even have internal fuses for each panel. As was mentioned earlier, a junction box allows you to bring all the solar panel's wires together in one place, which helps when troubleshooting, or when adding more panels. It also reduces the number of wires going from the roof to the controller.

The LP fridge vent is a commonly used route to run the wires, but I wouldn't be concerned about drilling a new hole in the roof for them, especially if it shortened the wire run considerably. It's easy to effectively seal small holes in an RV's roof.

Before you invest in flexible solar panels, I highly recommend that you do some research first. Yes, they're lighter, sometimes cheaper, they can form to curves (that's both good and bad) and you don't have to drill holes in your roof to mount them, but I think you'll find few RVers who are happy with them after a few years.

Solid frame "glass" panels are, in my experience, far more durable and reliable, and much less prone to having broken circuits. There are reasons glass panels have much better warranties. Depending on the type of roof you have, you might be able to install them without drilling holes.

Kev
 

Frank B

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Apr 23, 2005
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1,422
Location
Calgary, Alberta
What Kevin said, and more.


You can get narrow residential style panels that are good buys in price/watt as there are so many of them on the market these days.  These are typically high-voltage (40v) panels that work VERY well with modern MPPT solar controllers.  Put as many on the roof as you have room for.  No one ever complains of having too much solar, and the cost of one or two more panels compared to total system cost is usually very small.

http://www.rvforum.net/SMF_forum/index.php/topic,106669.msg960142.html#msg960142

Frank.
 

House Husband

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Joined
Jan 26, 2019
Posts
272
Location
K.C.MO.
If you really want to get the most out of your solar panels, set them up to tilt. I didn't want to be climbing on the roof to tilt the panels so I elected to use tilters from SolaRVector.
https://www.solarvector.net/
Push a switch up and the panels go up. Push the switch down and the panels go down and lock.

Richard
 
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