Solar Panel Installation

[millsrv]

I have a few questions regarding solar panel installation on my 07 Voyage.

Each panel requires four screws, what kind of sealant should I use to seal the screw holes in the roof?

There are no air conditioners on the roof so there is a huge area to mount the panels. I assume that under the fiberglass there is plywood or some similar material for the stainless wood screws to bite into, is this correct?

Is there any area of the roof that would be better for the panels?
I am very concerned with tree limbs damaging the panels, this coach is so tall that tree limbs are a constant worry.

Thanks to all for any information!

[Norm4015]

I have installed solar panels on rubber roofs with screws into the plywood. I drill the hole, fill it with sealant, insert and tighten the screw, then cover the screw head with sealant. I use Dicor lap sealant and have never had a leak.

My present motorhome has a fiberglass roof and I installed four panels with 3M industrial double-side tape so I didn't have to drill holes and install screws. Each of my panels have corner mounts (from AM Solar) and the foot of the mounts is about 1" x 1/2". I put 3M tape under each foot and that was over 5 years ago and they are still holding strong.

Place the panels so they won't be shaded by anything like the crank up TV antenna. And don't worry about tree limbs. Solar panels are built to a standard that allows them to rip limbs off trees without damaging the panels

[John Hilley]

Mine are installed with screws and Dicor self leveling sealant. Make sure you use large enough cable to compensate for voltage drop. Many people just size it for the current and don't take voltage drop into consideration. #2 is relatively safe for about 20'. Also mount the charge controller as close as possible to the batteries.

[bigskymt]

I used 4#6 1/2" SS Screws per panel and sitting on a bead of silicone which acts as an adhesive as well as sealer (per factory an 8mm plywood roof under the roof material).
If your coach is pre-wired for solar you'll want to locate the access area before placement of the panels, otherwise if you have a roof refer vent it's a good access point.

[Olive]

I have 4 large panels on my roof and the mounts are secured to the roof with 2 face tape rather than screws. Two of the panels I moved from my previous MH and then added 2 more. They are up there almost 3 years and holding fine. No screws, no holes, no sealant to keep up with. I bought the mounts that way but I would think it is a commercial 2 face tape.

My original stuff including these mounts came from Amsolar. I met them at a Life on Wheels conference in the 90s.

[RocketDork]

The tape they refer to is 3M VHB tape. Not even close to cheap, but the above testimony of performance seems to suggest that its worth it.

I'm also struggling with how to mount the panels I have too. Particularly the way to route the wiring. Most say use the Refer vent, but that's on the other side of the coach from my batteries. I've considered utilizing the pre-existing wiring location for the Satellite dish and running it to the battery side of the battery mode solenoid. Wiring diagram indicates 1/0 wire from there to batteries. Still a longer run that I'd like. So, assuming that I must penetrate the roof for the installation, how do I go about doing that?

[millsrv]

Thank you to all for the valuable information.
I am lucky to have found this forum and all of you great people!

[UFO Pilot]

Originally Posted by RocketDork

The tape they refer to is 3M VHB tape. Not even close to cheap, but the above testimony of performance seems to suggest that its worth it.

I'm also struggling with how to mount the panels I have too. Particularly the way to route the wiring. Most say use the Refer vent, but that's on the other side of the coach from my batteries. I've considered utilizing the pre-existing wiring location for the Satellite dish and running it to the battery side of the battery mode solenoid. Wiring diagram indicates 1/0 wire from there to batteries. Still a longer run that I'd like. So, assuming that I must penetrate the roof for the installation, how do I go about doing that?

The wire for my solar panel runs down the gray/black tank vent.

[dc8cappie]

Here is a paper by Handy Bob that is very interesting reading. Enjoy.

HandyBob's Blog

[RocketDork]

I've seen that. He does have some good points.

I'm not really worried about the system that I've got. I think I've got the right components, wire gauge, etc. The thing I'm struggling with right now is how to penetrate the roof to get the wiring installed. I plan to put the panels up front of my MH, the refer is at about the 2/3 back and on the opposite side as my batteries, the sewer vent is further back than that. I don't believe I have an option that positions the panels as well. I have made the decision that I must penetrate the roof to get the wiring installed. I just don't know how to do that without creating other issues.

[John Hilley]

Looking at your floor plan, it looks like your best bet is to enter thru the front cap roof, into the overhead cabinet area and down to the battery isolation solenoid. I removed my dinette and put in a credenza under the window. I wanted 12 volt DC power in the credenza and picked it up off the battery isolation solenoid. There is an actual opening going from the dash directly into the box housing the solenoid. I have also run antenna cables from the roof into the overhead cabinet and then down the A-frame on either side of the windshield into the dash. There are weather proof entries for bringing larger coaxes into vehicles that would work well for yoi.

[John Hilley]

Here is one type of water proof cable entry, with others you drill a hole, fill with sealant and then screw a cover over that.

Water proof cable entry

[RocketDork]

HEY! I like those! I may just have to make some.