Solar panel install on the trailer roof

[Neil&Anna]

If you haven't bought any of your solar panel equipment, I would highly recommend you buy a kit which includes everything you need. (panels, charge controller, cables, mounting hardware, fuses, MC4 connectors.

I'm installing a 200 Watt (2x100W) array from Renogy. I upgraded the charge controller to a Rover 20 amp MPPT as it allow me to double the array size to 400W without upgrading the charge controller.

You may want to consider a series/parallel design if you have 4 panels.

Renogy has numerous YouTube videos to help you.

[mike7840]

Originally Posted by BeGin

Oscarel. Thank you for those pics. I do have a solar sticker in that same spot and I was hoping the wires were ‘really there’ when I opened the panel. My trailer is in storage and I won’t get to access those wires until spring. I was thinking of mounting the solar charge controller on the bedroom side of the wall just to keep the living side a little cleaner looking. My controller will have Bluetooth so displays will be available on my phone.

QUESTIONS:
1 - When you had your panel open did you see any reason that would negate me mounting the controller on the bedroom side of the wall?
2 - Were the wires 8 awg per Jayco spec? I read one fellow found only 10 awg when he ‘opened’ the wall.

Thanks again. You have a neat install and you finding the wires where expected makes me feel better lol

Hello - Before you get too much further down the solar installation path, I would open the wall where the "solar ready" sticker is or should be to see if the wires are really there. When I got to work on my 2019 27RL travel trailer, I found that there was a missing wire and had to work extremely hard to convince the dealer and Jayco that indeed, there was a missing wire. There should be 2 wires coming from the roof plug to the spot where the controller might be mounted (near the sticker) and two more wires going from that same spot to the battery box. In my install, one of the wires going to the battery box was missing. After lots and lots of discussion, the dealer and Jayco got the 4th wire in place under warranty.



I have a Renogy controller similar to the one in the pictures and I mounted on the bedroom wall high enough up so that I wouldn't hit my head on it when I walked by.

[Goweb]

Do you already have a charge controller installed? Our X213 has wiring in the bathroom wall for the panel but did not come with it.

[Mad5581]

My northpoint was "pre wired" also. That said the wires they use OEM are good for about 100 watts. So I had to have mine re-wired to meet the demands of the 400 watts I installed. They also don't have the connection on the roof. The wires we just run upto a spot in the attic area and caped off. It was explained to me that even though they say they are "pre wired" and they are. But not for anything more then about 100 to 150 watts of solar. Might want to check on that. I had the wires ran and the connection box put on the roof that would handle 800 watts and ill I would have to do is upgrade my charge controller to add more solar later. I also had my dealer install the panels that way if there was ever an issue with roof leaks or loose panels the warranty they offered would cover anything that went wrong up there for 8 years. So far its been great. We also added 4 6 volt batteries so our bank of usable power is like 260 amp hours. With the residential fridge it gives us about 3 days of boon docking as long as the sun is out. Good luck I hope it goes smooth.

[JDooley]

I installed 2 300x 24v which go to a 100/50 victron controller. This charges 12 volt batteries.
The panels were screwed and glued with 5200 sealant then covered with eternabond tape after the sealant cured (2weeks).
Look at the 200w 24v panels narrow pannels and at 24v your wiring can carry 2x the amperage than 12v.

[BeGin]

Originally Posted by James AO

I’ve done four systems for myself, family and friends. I believe the easiest, fastest, safest, most secure attachment is using rubber jacketed well-nuts. They are self sealing and only require a 3/8” dia by 7/8” deep hole for each screw. I use stainless steel screws with them. You can buy them on Amazon.

Good tip on the rubber well nuts

[newhampshirecampers]

What can I control in my trailer with the use of solar panels?
Specifically how much wattage do I get?

[BeGin]

Folks
I bought 3 165 watt panels I’ll hook up in parallel and a Victron SmartSolar 100/30. I was limited to the more rectangular dimensions of these 36 cell panels as I installed MaxAirs etc and this restricted my available areas. I am hoping like heck I’ll find the wires where they are supposed to be in the wall, since pre-wired for solar, in the spring AND that they are the 8 awg they are supposed to be. I’m not sure why Jayco is limiting the spec to 400 watts maybe because the OEM has a 30 amp breaker in the wiring between batteries and solar charge controller. With 8 awg wire you should be able to do 50 amps easily. However, I went with the 495 watts and a 100/30 controller as this should be enough and I have a generator to back me up if necessary. At the moment, pending further input, I’m going to use the additional aluminum brackets sciencenerd recommended and try to screw where I can into a roof truss. Jayco provided the roof truss layout diagram (thank you Customer Service at Jayco) and where I can’t find a truss I’ll use the rubber well nuts recommended by James AO. In summary, a mish mash of everyone’s recommendations. Thank you all .. and I’ll pay attention here for any further recommendations.

[BeGin]

Originally Posted by newhampshirecampers

What can I control in my trailer with the use of solar panels?
Specifically how much wattage do I get?

Solar panels are used to charge your batteries. From the batteries you can power anything you like assuming you utilize an inverter for AC in your system. Without using an inverter ie. just DC from batteries powers I can power my lights, furnace, fans, slideout etc.

Appliances tend to use most power hence when I run on just my batteries (two BB10012’s) I put fridge and water heater on gas. They could run on battery DC but I opted for gas to save electrical energy. I used an inverter only when I wanted to use Keurig (gotta have my coffee), TV or microwave.

The wattage you get depends on the system you install and the availability of sunshine (number and quality of panels, controller, shade or direct sunlight etc)

[JDooley]

Dont run more panels than the prewire can handle. The prewire only runs from roof entry point/plate to the house battery location and terminate with wirenuts in a box. You will need to place a shutoff at the charge controller location and a fuse after the controller and before the battery

[jimmoore13]

Lots of great info here already.

One point. Renology and Windy Nation are among the better DIY solar kits.
I had Windy Nation, and I now have Renology.

Renology's mounting brackets are "better." Why? They have two screw holes per bracket. Windy Nation's brackets have only one. Most of the illustrations from others show similar brackets.

3/8" plywood (typical roof substrate) is more than adequate to hold a nominal 2' x 4' solar panel with 8 screws. Get some butyl tape for under the brackets and some Dicor for the tops of the screws/brackets, and you'll get a nice, dry installation.

One more suggestion. The Renology systems come with enough "drill point mini hex-head lag screws" to do the job. My personal preference is to drill an 1/8" pilot hole for each screw to minimize plywood damage from the drill-point lags. The pilot hole also guides the screw in and avoids any skidding about as a chintzy drill point screw struggles to gain bite. It also eases the mini-lag thru your roof membrane.

Your 400 watt system will have a total of 32 screws holding down the panels. You'll have no worries on that front.

[JDooley]

I made brackets from 2x2 alum. Angle. Used 2 screws and 5200 adhesive sealant under the foot
I used 2 1/4-20 rivnuts in the panel frame. Bolted frame to bracket with ss screws and backed up with aviation nuts.
Sealed over foot with eternabond tape after sealant cured.

[IrishSettler]

I have two Renogy 160 watt flexible panels. I matched the contour of my 2019 - 264BH with the panels. The panels are cemented to the roof by GE construction caulking with bathroom tub sealer around the border.
I mounted a Renogy 40A MTTP Controler and BT-1 monitor in the front storage area. The wires are run down the front face of the trailer and into the flooring of the storage space. The wiring from the two Interstate DP-24 batteries are also run through the same hole.
No holes in the roof. I can read the monitor without getting out of my pickup. The panels have close to 20,000 miles on them since they were installed.

[jimmoore13]

Use Butyl tape UNDER the bracket to seal between the bracket and the roof membrane.
https://smile.amazon.com/Dicor-BT-18...8423199&sr=8-9

This stuff can be applied to the underside of the bracket...two strips wide. When you snug down the screws, this stuff squashes out and completely seals EVERYTHING. You'll love it. But work in fairly warm weather so it's not too stiff.

Then add Dicor self-leveling sealant on top of the screw heads. You don't need to smear it around the bracket...the butyl tape takes care of that.

Your brackets do NOT need to be pre-bent to any angle. They are flexible enough to adjust to any slight variations caused by the crown of the roof.

I'm 71, and I did my installation in a few hours start to finish...from unpacking the panels, attaching the brackets, hauling them up onto the roof, laying out the chalkline to keep them (pretty) straight, applying butyl tape and later Dicor,...including cutting cables, adding connectors, dressing the cables under the panels, and so on.

This is an easier job than it seems.

One last tip. I bought "3rd party" connectors and tools. Buy Renology connectors and GOOD tools. Everything works, but the connectors I bought aren't nearly as robust as the ones supplied by Renology.

ALSO, you say you're pre-wired. My rig came with #10 AWG wire suitable for up to 30 amps. 4 x 100 watt panels can put out UP TO 30 amps. #10 is enough.

Find out where the wire is routed...I called the factory. You may have a sticker, but call anyway. I got valuable info on what I might encounter. I recessed my charge controller, so I had a nice big hole to see inside the wall cavity. The jacket on the wire will be embossed with the wire gauge (by law). You may need to use a flashlight at a low angle to see the wire gauge, but it will be there somewhere.

One of my wires was a bit short. I spliced on a short length of #10 AWG using a high quality crimp connector gain a bit more length and ease installation. Not a wire nut, as these might vibrate loose and fall off.

IF YOU RECESS YOUR PANEL, this is the type of tool to use. Illustration, not recommendation: https://smile.amazon.com/Rockwell-RK...dDbGljaz10cnVl
This kind of saw will cut a meticulously perfect hole in the paper thin paneling they use for walls in an RV, and it won't chip it or splinter it. These are VERY precise. Any brand will do. And, unlike a jig saw, the blade won't be took long and bang on the other side of the wall cavity. My charge controller looks as if it came with the rig...better.

FINALLY, bear in mind how fragile that wall paneling is. Be VERY gentle snugging up the screws that hold your charge controller. Recessing the panel has the added advantage of having the wall actually carry the weight of the charge controller rather than having it hang of the surface of the wall.

GORILLA GLUE does wonders at holding a screw in wood in the interior of your rig. Gorilla glue is like Great Stuff expanding foam insulation. A little goes a long way, and it expands and can make a mess. Apply to the threads sparingly, and it's like adding LocTite to a bolt. The screws stay put.

[IrishSettler]

To Jimmoore13,
Keep up the good work!
I’m going on 73��.

[BeGin]

Originally Posted by JDooley

Dont run more panels than the prewire can handle. The prewire only runs from roof entry point/plate to the house battery location and terminate with wirenuts in a box. You will need to place a shutoff at the charge controller location and a fuse after the controller and before the battery

Pre-wire is supposed to be 8 awg which can handle 50 amps in this situation. I’m installing a 50A DC breaker between solar panels and controller and the OEM pre-wire has a 30A DC breaker between controller and batteries so all should be well. Thanks for the tips.

[BeGin]

Originally Posted by IrishSettler

To Jimmoore13,
Keep up the good work!
I’m going on 73��.

Boys I”m 70 and never even thought of this as an issue lol

[BeGin]

Originally Posted by jimmoore13

IF YOU RECESS YOUR PANEL, this is the type of tool to use. Illustration, not recommendation: https://smile.amazon.com/Rockwell-RK...dDbGljaz10cnVl
This kind of saw will cut a meticulously perfect hole in the paper thin paneling they use for walls in an RV, and it won't chip it or splinter it. These are VERY precise. Any brand will do. And, unlike a jig saw, the blade won't be took long and bang on the other side of the wall cavity. My charge controller looks as if it came with the rig...better.
.

Jimmoore13 .. Yes I have and intend to use that tool. I used it in the past to cut up door frames when laying hardwood and it was my first thought for the panelling hole. I am going to see if I can glue some wood behind the panelling so any mounting screws will have a better purchase for the wall mount of the controller.

[MichaelO]

Originally Posted by jimmoore13

Use Butyl tape UNDER the bracket to seal between the bracket and the roof membrane.
https://smile.amazon.com/Dicor-BT-18...8423199&sr=8-9

This stuff can be applied to the underside of the bracket...two strips wide. When you snug down the screws, this stuff squashes out and completely seals EVERYTHING. You'll love it. But work in fairly warm weather so it's not too stiff.

Then add Dicor self-leveling sealant on top of the screw heads. You don't need to smear it around the bracket...the butyl tape takes care of that.

Your brackets do NOT need to be pre-bent to any angle. They are flexible enough to adjust to any slight variations caused by the crown of the roof.

I'm 71, and I did my installation in a few hours start to finish...from unpacking the panels, attaching the brackets, hauling them up onto the roof, laying out the chalkline to keep them (pretty) straight, applying butyl tape and later Dicor,...including cutting cables, adding connectors, dressing the cables under the panels, and so on.

This is an easier job than it seems.

One last tip. I bought "3rd party" connectors and tools. Buy Renology connectors and GOOD tools. Everything works, but the connectors I bought aren't nearly as robust as the ones supplied by Renology.

ALSO, you say you're pre-wired. My rig came with #10 AWG wire suitable for up to 30 amps. 4 x 100 watt panels can put out UP TO 30 amps. #10 is enough.

Find out where the wire is routed...I called the factory. You may have a sticker, but call anyway. I got valuable info on what I might encounter. I recessed my charge controller, so I had a nice big hole to see inside the wall cavity. The jacket on the wire will be embossed with the wire gauge (by law). You may need to use a flashlight at a low angle to see the wire gauge, but it will be there somewhere.

One of my wires was a bit short. I spliced on a short length of #10 AWG using a high quality crimp connector gain a bit more length and ease installation. Not a wire nut, as these might vibrate loose and fall off.

IF YOU RECESS YOUR PANEL, this is the type of tool to use. Illustration, not recommendation: https://smile.amazon.com/Rockwell-RK...dDbGljaz10cnVl
This kind of saw will cut a meticulously perfect hole in the paper thin paneling they use for walls in an RV, and it won't chip it or splinter it. These are VERY precise. Any brand will do. And, unlike a jig saw, the blade won't be took long and bang on the other side of the wall cavity. My charge controller looks as if it came with the rig...better.

FINALLY, bear in mind how fragile that wall paneling is. Be VERY gentle snugging up the screws that hold your charge controller. Recessing the panel has the added advantage of having the wall actually carry the weight of the charge controller rather than having it hang of the surface of the wall.

GORILLA GLUE does wonders at holding a screw in wood in the interior of your rig. Gorilla glue is like Great Stuff expanding foam insulation. A little goes a long way, and it expands and can make a mess. Apply to the threads sparingly, and it's like adding LocTite to a bolt. The screws stay put.

Do you have a pic of how your recessed panel?

[krbjmpr]

1. Find studs. Brackets can typically move along solar panel as edges are usually extruded.
2. Screw size depends on panel bracket size. I would use largest screw that will fit in predrilled hole in bracket.
3. Maybe. Depends a lot how brackets attach to panel. If brackets are basic j or z style, you might need to tweak them. If bracket slides into channel on panel, there may be enough slop there already. Using KY Jelly, stop laughing, I am serious, but only water based will help slide - seriously stop laughing! - brackets along with residue being safe for all roof types.
4. This is what I would do. First, make darn sure you are in middle of stud. Don't drill directly into membrane. Cut small X with knife so membrane isn't pulled / torn. Better method is to use a wood plug cutter and "cut" a small hole in membrane. Predrill holes where screwpoints leave an impression. You did a test layout, right? Add small strip of butyl tape, screw down panel / bracket, seal screw and bracket edges with very small amount of Dicor. Now cover bracket with epdm tape, try to minimize cuts in tape. Then do it again from other direction, don't allow cuts to overlap.
5. I don't have your trailer, but lets say your panels put out 400w at 15v. 400 / 15 = 26 Amps ( a bit more actually). That is 10ga size wire (rated 30A). Panel likely won't do that much unless in labratory but still... I have around 1500w of 90v panels with a 17A max current on 10ga wire.
6a. Use high voltage panels to lower losses due to current and resistance.
6b. Use MPPT controller to get more power out of lower light.
6c. I attached copper coils to back of my panels using JBWeld to transfer heat out of panels and into my water heater. When water heater hit 160F, a valve switched to small radiator. Cooler panels = higher output. In winter time, radiator was moved into storage compartment. Very effective heating the compartment to over 100F.
6d. Make a panel washer out of pvc pipe, attach to edges so shadow is not cast. It is a pita to climb on top with water hose to rinse off panels.
6e. Test installation with battery leaf blower. If panels stay in place with 130mph out of blower, probably okay at 70mph. Check sealant and seals.
6f. After install, use wire loom to cover all wiring.
6g. Seal panel connectors with self-fusing rubber electrical tape (not vinyl!).
6h. If you can manage, fuse each panel as close to panel as possible. Fuse panels after all have been combined into OEM run. Why? There is no fuse on this line usually.
6i. Make a broom out of pvc pipe and threaded connections. Why? Sweep debris off panels from ladder or ground. Gray conduit also works, and is stiffer. Take apart when not in use.
6j. Panels get hot. Very hot. I glued aluminum flashing under mine (used Dicor sealant) to reflect heat back up and heat water faster.
6k. Underside of panels attract wasp and dirt daubers. I used 1.5in wide x .375in flat stock and drilled a series of holes that I chamfered. Used flat head machine bolts and nylock nuts to keep in place. *Metal* window screen is forced on protruding screws, then washer, then another nylock nut. A big circle of window screen is held in place by screws, presses against bottom of panel and keeps bugs out. 99% effective. Later spray painted new screens because first set rusted badly.
6l. When comes time for new roof, I will have angle steel installed as well to facilitate mounting my toys better in future.
6m. Replace TV antenna with omnidirectional on top of AC. More panel space.
6n. My plumbing vents were trimmed down to minimum to minimize shadows. Discovered I can mount panels over vents now... Though expensive, replace AC with low profile models.
6o. Replace crank up roof vents with low profile MaxAir vents. Do it anyways.
6p. Make sure all panels have diode isolators. Google it. Very important on those beside AC(s).
6q. A manual tilt up bracket / panel mount mechanism allows more panels to be installed. Tilt up and out of way to make walk path on roof. Also may help to aim Better toward Sun according to latitude. Also helps to easily remove a panel for replacement vs having to slide all panels out to replace middle without removing screws.
6r. I don't know name, but consider using item that is wood screw on one end, machine bolt on other. Really makes mounting (and removal) of panels MUCH easier.
6s. If really into cold weather camping, polyamide (sp?) heating panels on back of solar panels helps to thaw to melt snow / ice off. Me? I just reverse my panel water pump and use water from water heater to circulate and warm panels. Fire truck rolled up on me in Wy once because somebody saw steam coming off top of coach and thought I was on fire.
6t - 6z. I can't give up all my tricks now.

If you are considering 100w panels, look into 350w single panels. Also, think about using 'stick on' panels on top of nickel flashing / sheet that has copper brazed onto it for water heating purposes. Much better heat transfer, and easier to design what you want - my opinion.

Originally Posted by BeGin

Folks
I intend to mount 400W of solar panels on my roof next spring. I have a 2019 White Hawk 27RB. The trailer is pre-wired for solar so there is a connector on the roof now that will bring my power into the trailer.

I have some panel mounting questions that I would appreciate some help with.

1. Can I screw into the normal roof plywood and be secure? (I suspect it would be desirable to find a roof stud/frame to screw to but the positioning and spacing of brackets may not lend themselves to screwing into a stud/frame piece in most cases.)
2. What specification of wood screw including length should I use to secure the brackets to the roof?
3. Given the slight curvature of the roof will I need to bend the bracket bases a bit to stay flush with roof?
4. Is Dicor Self-leveling Lap Sealant what I should use to make my installation water proof?
5. Anyone who has installed panels on a roof similar to the 27RB, I would love to hear your experiences and panel dimensions you were able to install . I think I need to do a parallel run of four 100W panels as with the OEM fans/antennae/AC etc on the roof I believe I’m somewhat restricted by panel physical size in the various spaces available.
6. Any other suggestions you may have.

Thanks to anyone who can offer some guidance.