Foretravel Motorhome Forums => Foretravel Renovations => Topic started by: Kidspot on January 04, 2021, 01:08:11 am
Title: Seeking advice on several solar install aspects...
Post by: Kidspot on January 04, 2021, 01:08:11 am
Got several issues on my upcoming solar install I'd appreciate advice on:
1) Wiring run advice: I'm about to start running wires - pretty sure I'm locating the batteries/bus bars and solar charge controllers, etc.. behind our couch on the drivers side - there is a lot of unused space back there and it frees up the entire existing battery bay for storage, plus it will be a very easily accessible location to work and do the wiring (Just slide the couch out whenever access is needed).
Running wires from the roof to this area is something I'm still considering - I've run camera wires (4 camera system) down the refrigerator vent to the front and could do the same with the 3 pairs of 2 gauge wiring I'm running from the roof down. I've also considered running thru the penetration up front where the satellite dish is (I'm about to remove it to make room for panels) but I'm not convinced this much wire would fit and I'm not familiar with the path of this "run" I guess I'm leaning toward the fridge vent mostly because I'm familiar with it and am confident about the "run" from one end to the other. Open to comments and other recommendations from the community...
Running 3 series sets of 4-5 panels each (14 panels total - 210 watts each) to 3 - 150/70 Victron MPPT's. running 3 sets of 2 gauge wire from the combiner boxes down (3 separate combiner boxes).
2) If I run them down the fridge vent, do I need to shield them against heat from the fridge area in some conduit or something similar?
3) Panel Mounting Advice: (I've read lots of threads about this already but remain undecided) I'm using 6" L-brackets from continuous resources with VHB tape (chose the 6" to avoid as much roof shading from A/C and other roof "stuff" as possible) As soon as I locate a heated garage or warmer weather I'll sand/prime the fiberglass and set the taped "feet". I will double up on the L brackets at least for the front 4 panels leading edges that will see the most wind (So they will look more like an upside down "T" instead of an "L") - Should I use screws in the brackets into the roof as well? I'm not worried too much about penetrations, considering how many are already on a roof - once sealed with sikaflex and eternabond tape they should be well sealed. Just not sure how thick the plywood under the fiberglass is ... will it be thick enough to really hold the screws? I know where the aluminum roof frame members are at (Marked them during the last frost), but doubt that they will line up with where the "L" brackets go... Should I double up on the L brackets on all panels?
I know this was a long post to read, so thank you in advance for your time, comments and advice.
Title: Re: Seeking advice on several solar install aspects...
Post by: folivier on January 04, 2021, 08:21:11 am
My only tip is using any type of adhesive whether tape or glue is it will only adhere to the top layer of gelcoat. If you're comfortable with that being the only point of attachment, ok. If not then I'd consider adding a screw to get down into the plywood for better attachment.
Title: Re: Seeking advice on several solar install aspects...
Post by: Chuck & Jeannie on January 04, 2021, 09:28:22 am
1. Running 3 series sets of 4-5 panels each (14 panels total - 210 watts each)
2. Panel Mounting Advice:
1. You are fitting 14 panels on a 36' roof? :o I would like to see a rough sketch of your layout. What (physical) size panels?
2. Panel mounting. You will get many varied opinions here on that subject. To give you one point of reference, we had our PV system installed at AM Solar 6 years ago. They used glue-on brackets stuck to our original gel coat roof surface. All the brackets are still sticking tightly to our roof. Our coach sits out in the Texas sun unprotected year round - very challenging conditions for the bracket stickum.
PV System, Installation, at AM Solar (https://www.foreforums.com/index.php?topic=26206.msg209349#msg209349)
Title: Re: Seeking advice on several solar install aspects...
Post by: Pierce & Gaylie Stewart on January 04, 2021, 09:46:51 am
I installed ours around 11 years ago. I bought some brackets but made some also. I mounted 4 big panels using screws into the aluminum roof members and found them using a regular stud finder. I drilled and used electrical flex cable and a 90 to send the wires down to the Midnite 150 controller right below. I use a series/parallel wiring arrangement but some go all parallel.
It works as well today as it did when installed. Here is a link to photos showing the installation: U300 36' Solar Installation - Google Photos (https://goo.gl/photos/9KGwM2Zk28f5s4NW8) I have a complete list of everything I used including the prices and links to the sources. 1140 potential watts cost about $1400 total including controller, wires, etc.
I would not change a thing today with the exception being that panels are more efficient now so the wattage would be a couple of hundred more.
Pierce
Title: Re: Seeking advice on several solar install aspects...
Post by: dsd on January 04, 2021, 09:56:04 am
https://youtu.be/qRCiUOpsW2U Drilling holes thru your fiberglass will be subject to cracking out from those holes in the future. Fiberglass ages and becomes more brittle. I've had really good results with the west Marine products and have have never had a failure. Good stuff. Scott
Title: Re: Seeking advice on several solar install aspects...
Post by: Pierce & Gaylie Stewart on January 04, 2021, 10:10:37 am
Scott,
When I painted our roof, I pulled a couple hundred Philips head screws out that were OEM in vents, antenna, etc. No cracks. I replaced all with stainless screws and used stainless screws to mount the solar panels. So, with lots and lots of screws already up there, I don't see a problem.
I've used West System epoxy in the past and it's good stuff. Too bad they didn't build the coach with it and cloth instead of mat.
The epoxy would have worked OK in the solar application but I wanted something that could be removed for painting or replacing the panels with the newer more efficient models. When I painted the roof, It was easy with a nice flat surface.
Pierce
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 04, 2021, 10:29:26 am
Here is the layout of the panels on the roof - yes, it's tight. All are tiltable, for the purpose of roof access. This is an actual photo of the roof (I used the tape measure in the image to get scale correct) and the black rectangles are 1-2" oversize from our actual panel dimensions to allow for a little "wiggle" room. These are the panels https://www.continuousresources.com/collections/solar-panels (https://www.continuousresources.com/collections/solar-panels-and-hardware/products/hightec-solar-210w-36-cell-12v-nominal-solar-panel-6-busbar) I am using the published specs, and maybe I should unbox one to measure it for myself ... lol ... I may be surprised :-) - published specs: 58.8125" x 26.75" - on my plan they are 59"x29" to account for small inaccuracies.
I also am leaving myself the option of ground mounting some of the panels if necessary ... though hoping it won't come to that.
Regarding the gel coat - what is left of it will probably come off where the brackets go down when I sand the oxidized layer off and apply the 3m Primer 94 (the primer recommended by 3m when I contacted them).
Can anyone tell me how thick the plywood is under the roof? Hoping it's 3/8" or thicker... ;-)
I am grateful for the comments/advice/help -
Aloha, Tim
Title: Re: Seeking advice on several solar install aspects...
Post by: nitehawk on January 04, 2021, 10:46:57 am
Just curious. Has anyone experienced their solar panel(s) coming up off the roof of their coach? Not hearsay but actual experience? So far I haven't even heard of anything like it. I wonder about the airflow on the GV models and also on the "bus" style models. Obviously they would be different. From experience with our 1989 GV style I know we haven't had any issues with the airflow creating problems. I have accidentally left "stuff" on the roof and drove 30 miles to and back from a campground and the "stuff" was still laying up on the roof. Our Kingdome (located behind the front AC, was totally loose. Nothing holding it in place but its weight. My four solar panels are mounted about 4" above the roof surface with SS screws and adhesive. This about 4-5 years ago and still tight. I will say that the SS screws are only in the fiberglass. Seems the plywood and fiberglass have separated over time. Granted, we don't exceed 70 MPH other than downhill + tailwind, for any length of time. I am not trying to change the OP subject, but pertinent answers here might aid his decision making on this subject.
Title: Re: Seeking advice on several solar install aspects...
Post by: dsd on January 04, 2021, 10:50:16 am
When I painted our roof, I pulled a couple hundred Philips head screws out that were OEM in vents, antenna, etc. No cracks. I replaced all with stainless screws and used stainless screws to mount the solar panels. So, with lots and lots of screws already up there, I don't see a problem.
I've used West System epoxy in the past and it's good stuff. Too bad they didn't build the coach with it and cloth instead of mat.
The epoxy would have worked OK in the solar application but I wanted something that could be removed for painting or replacing the panels with the newer more efficient models. When I painted the roof, It was easy with a nice flat surface.
Pierce
I really do like the idea of attaching to the sub structure but may times can't. Everything has a down side. I guess I have had too many repairs of cracks out of screw holes. IMO if you drill a hole in glass it is eventually going to crack out even when it has been countersunk on both sides. Just the screw going thru induces stress promoting cracks. DWMYH. You will never remove the mounts once there bonded on without damage. Ever. So for sure that is a double bladed sword. Lol Scott
Title: Re: Seeking advice on several solar install aspects...
Post by: dsd on January 04, 2021, 11:04:34 am
Tim you mention that they are tiltable. I can't imagine any need for going under them once installed other than cleaning. Just concerned that anything that is easily movable will eventually come loose? Scott
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 04, 2021, 11:11:29 am
Tim you mention that they are tiltable. I can't imagine any need for going under them once installed other than cleaning. Just concerned that anything that is easily movable will eventually come loose? Scott
To provide roof access - annual A/C cleaning, etc.. since I did not leave walk around room, I thought this was necessary.
Title: Re: Seeking advice on several solar install aspects...
Post by: nitehawk on January 04, 2021, 11:21:05 am
Ours tilt but one direction only, by removing two bolts opposite the hinged side. This for cleaning. Removal of the bolts does take two wrenches to remove the bolts and also to loosen the hinge bolts, even tho I used "shakeproof" nuts (not nylok type).
Title: Re: Seeking advice on several solar install aspects...
Post by: bdale on January 04, 2021, 11:28:24 am
...You will never remove the mounts once there bonded on without damage. Ever. So for sure that is a double bladed sword. Lol Scott
Epoxy is no doubt very difficult to remove. The OP mentions his intent to use VHB tape, which is a very common and proven method for mounting solar panels. And it is very easy to remove. I changed the alignment of one of my panels after it had been stuck down for a month or so. It took about 60 seconds to split the tape with an oscillating saw blade, then another minute or so to clean up the residue with rubbing alcohol at each mount. No damage to the fiberglass.
Title: Re: Seeking advice on several solar install aspects...
Post by: JohnFitz on January 04, 2021, 11:47:49 am
Can anyone tell me how thick the plywood is under the roof? Hoping it's 3/8" or thicker... ;-)
To find out exactly what you have you should be able to remove the cover on the vent above the microwave and see the cross section of the roof. I know it's visible on my '91 and only 4 screws to do it.
If it were me I would use VHB and follow all the recommend applications tips and primers, etc.
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 04, 2021, 12:00:03 pm
If I can ask another semi-related question (related to wiring, not panel mounting, that is)- the bolts holding down the seatbelts where the factory sofa used to be - I assume they go directly into the frame - can you see any issue adding a second 4/0 ground wire to one of them from the bus bar (since they are only 18 inches away, it seems the most straightforward way to do this) I would cut away enough subfloor to make direct contact with the frame itself to the lug. - I could also tie all the ground connections for the charge controllers, etc there too at the same time. While I'm in this "mess" I plan to run a second 4/0 wire to the inverter, just in case we decide to upgrade to a 5k inverter down the road, so a second equal sized chassis ground seems to be in order ;-)
Very grateful to bounce these things off the group collective here -
Aloha, Tim
Title: Re: Seeking advice on several solar install aspects...
Post by: Dave & Diane on January 04, 2021, 12:26:13 pm
Let me chime in on the use of VHB tape for securing solar panels. I was initially concerned about using the VHB tape, whether or not it would be strong enough to hold my panels. I have 4 residential 65x39 size 300 watt 24 volt panels on my coach. The mounts I used were custom made by Roger on the forum. They are a foot long each and take into account the curvature of the Foretravel roof. I used the 1.5" VHB tape to secure the panels. The most important step is the prep of the area you are going to adhere the mounts too. You must use the 3m adhesion promoter before applying the VHB tape. You get one try to set the panel down, so make sure you place it accurately or break out the piano wire. The panels are NOT going anywhere. In my opinion, the commercial outlets use very small mounting brackets, which could be a problem whether screwed in or secured by VHB tape. If you are using the traditional 12 volt smaller "RV" solar panels, they are lighter so less worry. The thing with those panels is that they are lower wattage and pricey when compared to the 60 or 72 cell panels available today. If you have the real estate on the roof to accommodate the larger panels that may be a better choice. You can use the smaller panels to fill in spaces that are too small for the big panels. I've kept a small space between sets of panels to walk through to get to the front of the coach as you will need to clean the roof and the panels periodically. Lots of things out there to consider. Good luck with your project.
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 04, 2021, 01:46:49 pm
Thanks D&D - I started by looking at 420 watt panels, but I can fit a lot more wattage using the 210s (better use of space on the roof)- plus they are already sitting in my garage ;-) - I appreciate your comments - the small surface area of the commercial mounts was my concern as well - I'm currently waiting on a callback from Continuous Resources to see about picking up a few more of the L brackets so I can double up on them and increase the surface area - if I can, then I will not worry about screws and just wait for cooperative temperatures to do the install. In the meantime I will get the wires run, layout the electronics and install the LifePo4 batteries when they arrive.
Let me chime in on the use of VHB tape for securing solar panels. I was initially concerned about using the VHB tape, whether or not it would be strong enough to hold my panels. I have 4 residential 65x39 size 300 watt 24 volt panels on my coach. The mounts I used were custom made by Roger on the forum. They are a foot long each and take into account the curvature of the Foretravel roof. I used the 1.5" VHB tape to secure the panels. The most important step is the prep of the area you are going to adhere the mounts too. You must use the 3m adhesion promoter before applying the VHB tape. You get one try to set the panel down, so make sure you place it accurately or break out the piano wire. The panels are NOT going anywhere. In my opinion, the commercial outlets use very small mounting brackets, which could be a problem whether screwed in or secured by VHB tape. If you are using the traditional 12 volt smaller "RV" solar panels, they are lighter so less worry. The thing with those panels is that they are lower wattage and pricey when compared to the 60 or 72 cell panels available today. If you have the real estate on the roof to accommodate the larger panels that may be a better choice. You can use the smaller panels to fill in spaces that are too small for the big panels. I've kept a small space between sets of panels to walk through to get to the front of the coach as you will need to clean the roof and the panels periodically. Lots of things out there to consider. Good luck with your project.
Title: Re: Seeking advice on several solar install aspects...
Post by: Roger & Susan in Home2 on January 04, 2021, 02:53:38 pm
There are many VHB tape variants, all have specific application objectives. I used 5952 based on the advice I got from 3M friends who worked in the Automotive Divison. It is a bit thicker, more adaptable to slightly irregular surfaces and slightly misaligned surfces (not quite parallel). It has a 91 psi tensile strength and very good shear strength.
Amazon.com: 3M VHB Heavy Duty Mounting Tape 5952, 1.5" width x 5yd length (1... (https://amazon.com/gp/product/B00HLY7BBO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
This is the recommended surface cleaner/adhesion promoter. Petroleum based solvents are inot appropriate, they interfere with the bonding process. Amazon.com: 3M 111 Clear Tape Primer - Liquid Bottle - For Use With 3M VHB... (https://amazon.com/gp/product/B00745Z8BK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
A very light sanding with 320 or 400 grit paper where the mounts attach is sufficient. Put the mounts on the oanel and put the panel in place. Blue tape around each mounting point, prep where the tape goes, don't forget the mount itself. Tape on the roof, roll with a J roller, remove backing film and place the panel. Press down firmly and let it sit over night. Remove the panel from the mounts and caulk all four sides of the mount/roof intersection with 3M 4000 UV adhesive/sealant caulk.
I used 12"x1.75"x3" aluminum angles at each corner. The angles were bent at 92° to account fot the curvatur of the roof and the width of the panels so the they sat flat on the roof and the flanges are parallel to the sides of the panels. The angle changes woth panel size. This gives me more than 6,500 pounds holding on each panel. I think a 6" long one in each corner would be sufficient.
I removed and repositioned one panel. It was an all day job, tape and caulk are very tough.
Do your energy balance math again. How much power do you use each day? What is the range between min and max? How much battery capacity do you have? Are you running an LP refrig or residential? Almost no one has sufficient battery or inverter capacity to run AC for any length of time so don't plan on it. For most with a residential refrig, typical use will be about 3200 watts per day +/- a lot depending on user. Without a residential closer to 1800 watts per day. Same +/- specs.
Back of the envelope numbers are 1600 watts of non tilting panels on the roof of your coach will get you about 3200 watts or more on 1/2 of the days of the year. A 1/4 of the year you will get an average of about 2,400. The rest of the year will average about 1600 watts per day. Where you are, what direction you are pointing, shade, clouds all make a difference. Solar panels mounted on a motorhome are not ideal. Tilting is dangerous, add more panels instead.
Leave room to get around on the roof for normal service and maint.
Panels in parallel are going to get you the maximum output especially relative to shade. Each panel should be fused. I used 8 and 10 ga UV rated solar panel cables for ech panel, run them down behind the refrig through the ref vent, through the floor to a fuse block then to solar charger. Output should be fused and switched to the batteries. At that end it should be fused as well.
Your panels can be 2-2 1/2 " off the roof (room for getting your hand underneath). Any shading due to AC covers is minimal at most during most of the year. When sun angles are so low that the AC cover's shade is an issue everything else will be worse.
I have 1200 watts now and will likely add 2 more 60 cell panels to get closer to 1900 watts and still have adequate access. They will add about 2 months to the time each year where we can be land line and generator independent. All bets are off if you get a week of rain.
If you don't have to do this now maybe us the coach for a year or so and learn how it works and you do in it. Good idea for almost everything.
Roger
Title: Re: Seeking advice on several solar install aspects...
Post by: JohnFitz on January 04, 2021, 03:25:42 pm
Attached is 3M presentation for engineers. There are guidelines for how much VHB tape you might need (generally 40-60 lbs. per square inch but look at data page for the one you select), but you will still just have to guess at the possible wind load and decide what safety factor you want. Those forward panels are obviously going to be challenged with wind buffeting. I recall reading somewhere about another member needed to add a deflector to solve a wind noise/buffeting issue. Another alternative to VHB is 3M 4200 - it's removable too. It's tensile strength is much higher at 180 lbs./in2. Boaters use this on fiberglass a lot.
As a side note: I wonder about the practicality of tilting panels for getting around on the roof. You don't want to fall off dodging panels.
Title: Re: Seeking advice on several solar install aspects...
Post by: Pierce & Gaylie Stewart on January 04, 2021, 03:40:32 pm
In my opinion, tilting the panels is not necessary. Even if you tilt them. the sun will only be perpendicular for a moment during the day. A little more to be gained but not worth the risk. Ours do not tilt but batteries are on float before noon and we only have 1140 potential watts.
Pierce
Title: Re: Seeking advice on several solar install aspects...
Post by: Elliott on January 04, 2021, 03:49:12 pm
In my opinion, tilting the panels is not necessary. Even if you tilt them. the sun will only be perpendicular for a moment during the day.
I have found that the sun is so low on the horizon during the winter that tilting the panels moves the needle quite a bit for us. This is with 740 watts + AGM batteries that don't charge as quickly (on our 5er).
Title: Re: Seeking advice on several solar install aspects...
Post by: Michelle on January 04, 2021, 04:01:19 pm
In my opinion, tilting the panels is not necessary. Even if you tilt them. the sun will only be perpendicular for a moment during the day.
Except in this case where OP needs a means to create a path to the A/C units, etc. on the roof for servicing (and also for cleaning the panels). With the proposed layout, if they are fixed, he cannot walk on the roof at all.
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 05, 2021, 11:10:54 am
Thanks Roger - all the parts are currently sitting here waiting for install, so the die has been cast, so to speak ;-) part of the process of coming to our current plan was after taking comments like yours into careful consideration. We went thru this planning process with our previous 500sf home when we had solar installed on it as well - it always generated much more than we had planned for or used, though that was in Hawaii and angled properly on a roof ... in a city that saw over 80 inches of rain a year (lots of cloudy days).
Our energy usage on our rig is based on 1/2 of our summertime residential use while running a 14k window A/C 24/7 and all electric appliances (30kw/daily) in a 2500sf home-so I planned for a 20kw battery bank, running from 20-80% capacity daily with 15kw solar collection capacity, based on 5 hrs of sun exposure during peak of summer months when it will most likely be needed (where we work in the summer time it can be 110°-115°f) - I know that getting full capacity in reality will be "rare" and I do plan to install an 8k window A/C unit in our rig - not planning on the roof top air if the generator is not running. The areas we work in 90% of the time have either no power or 15 amp on a looong extension cord (I set our inverter/charger to not draw more than 10 amps from shore power so we don't trip circuits when we are plugged in) - No residential fridge, running on LP but cooking is mostly electric (Induction/instant pot, toaster oven, etc... very little microwave) For most of the year when sun exposure is much more limited (like right now)I would only expect 1-2 hours at most, our usage will be much lower and the extra battery capacity will give us multiple cloudy day use between solar/generator recharging.
This is our home, and I didn't want power to be a limiting factor, at least as much as possible.
So, that was the reasoning behind all this - I started thinking about this over a year ago (oddly, just before the covid issue came up) and when we spent 2 months, during the first shutdown last March, in our truck camper travelling to visit my parents on the east coast it confirmed to us that we wanted to move back into a much smaller living space and spend more time with both my Father in Law and my parents who live on the West & East coasts respectively. God seems to be honoring this decision and allowing our work to expand geographically which makes this possible for us.
Grateful for your thoughts - can't tell you how many times I have scrapped my whole plan and started over from scratch during the last 6 months, but now it's time to move forward and let planning and reality meet (Collide?) :-)
There are many VHB tape variants, all have specific application objectives. I used 5952 based on the advice I got from 3M friends who worked in the Automotive Divison. It is a bit thicker, more adaptable to slightly irregular surfaces and slightly misaligned surfces (not quite parallel). It has a 91 psi tensile strength and very good shear strength.
Amazon.com: 3M VHB Heavy Duty Mounting Tape 5952, 1.5" width x 5yd length (1... (https://amazon.com/gp/product/B00HLY7BBO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
This is the recommended surface cleaner/adhesion promoter. Petroleum based solvents are inot appropriate, they interfere with the bonding process. Amazon.com: 3M 111 Clear Tape Primer - Liquid Bottle - For Use With 3M VHB... (https://amazon.com/gp/product/B00745Z8BK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1)
A very light sanding with 320 or 400 grit paper where the mounts attach is sufficient. Put the mounts on the oanel and put the panel in place. Blue tape around each mounting point, prep where the tape goes, don't forget the mount itself. Tape on the roof, roll with a J roller, remove backing film and place the panel. Press down firmly and let it sit over night. Remove the panel from the mounts and caulk all four sides of the mount/roof intersection with 3M 4000 UV adhesive/sealant caulk.
I used 12"x1.75"x3" aluminum angles at each corner. The angles were bent at 92° to account fot the curvatur of the roof and the width of the panels so the they sat flat on the roof and the flanges are parallel to the sides of the panels. The angle changes woth panel size. This gives me more than 6,500 pounds holding on each panel. I think a 6" long one in each corner would be sufficient.
I removed and repositioned one panel. It was an all day job, tape and caulk are very tough.
Do your energy balance math again. How much power do you use each day? What is the range between min and max? How much battery capacity do you have? Are you running an LP refrig or residential? Almost no one has sufficient battery or inverter capacity to run AC for any length of time so don't plan on it. For most with a residential refrig, typical use will be about 3200 watts per day +/- a lot depending on user. Without a residential closer to 1800 watts per day. Same +/- specs.
Back of the envelope numbers are 1600 watts of non tilting panels on the roof of your coach will get you about 3200 watts or more on 1/2 of the days of the year. A 1/4 of the year you will get an average of about 2,400. The rest of the year will average about 1600 watts per day. Where you are, what direction you are pointing, shade, clouds all make a difference. Solar panels mounted on a motorhome are not ideal. Tilting is dangerous, add more panels instead.
Leave room to get around on the roof for normal service and maint.
Panels in parallel are going to get you the maximum output especially relative to shade. Each panel should be fused. I used 8 and 10 ga UV rated solar panel cables for ech panel, run them down behind the refrig through the ref vent, through the floor to a fuse block then to solar charger. Output should be fused and switched to the batteries. At that end it should be fused as well.
Your panels can be 2-2 1/2 " off the roof (room for getting your hand underneath). Any shading due to AC covers is minimal at most during most of the year. When sun angles are so low that the AC cover's shade is an issue everything else will be worse.
I have 1200 watts now and will likely add 2 more 60 cell panels to get closer to 1900 watts and still have adequate access. They will add about 2 months to the time each year where we can be land line and generator independent. All bets are off if you get a week of rain.
If you don't have to do this now maybe us the coach for a year or so and learn how it works and you do in it. Good idea for almost everything.
Roger
Title: Re: Seeking advice on several solar install aspects...
Post by: Journey, Roam, Explore on January 05, 2021, 12:33:22 pm
I have 1400 Watts supposedly on the roof put in by two previous owners and AM solar did the final install with the controller and wiring including the lithium ion batteries. All of that is mounted where are the washer dryer used to be in the bathroom. The panels were mounted using VHB tape and I have had one or two mounts come loose and need to be remounted. I strongly strongly strongly advise not to use the layout as you propose. there will be times when you will need to get up on that roof and you have no room to move around with that layout you will find that unscrewing the panels and lifting them up will be a major hassle for short trips up there. as it is it's dodgy getting around my roof but at least I can put my feet down in between the panels and things like the vents and air conditioners. with your proposed layout you will not have that ability and it will take you time to unscrew them and how are you going to get to the other side of the panel to unscrew it without standing or putting some kind of weight down on it? As far as putting your controller and wiring underneath the couch I guess that would be a good place to do it but you do have a heater under there I expect. I also have my subwoofer there and the center drawer so there's not a whole lot of space under there now. If you do have a washer dryer in the bathroom and you don't use it much consider putting it in there or in the space above it if you have a similar arrangement as I do. That would make it much easier to run your wires. And if you decide to go with lithium, 600 amp hours plus a 3000 watt inverter plus a solar mppt controller and the BMS all fits in there nicely and there is a vented door and an air condition duct above it that can be blown into it to help cool things when you're charging. That's the way my previous owner did it with AM solar and I'm quite happy with that arrangement. Would I like to have more solder on the roof? yes. would I like to have less space to walk around in absolutely not. Why I don't like going on the roof often I've had to go up there several times in the last year to clean it to change out a fan and next year to paint it. When I do that I may change out some of my panels for newer ones with better energy density but I will be very mindful of being able to walk from the back of the roof to the front without having to tilt the panels or unscrew them. If you do want additional solar you could always take them out of the Bay and hook them up and tilt them on the side of the coach. A cable lock from the wheels to the back of the panels would secure them from theft. You couldn't add 3 320 w panels that way and just slide them into your Joey bed when not needed. Anyway just a thought. Good luck on your install. Bob
Title: Re: Seeking advice on several solar install aspects...
Post by: Roger & Susan in Home2 on January 05, 2021, 01:39:55 pm
Easy to run panel cables down behind refrig, through the floor to fuse block and charge controller above the water pump. From there easy connections to battery points. Your coach may have a different floor plan than mine but plan your use space carefully.
Mount parts on a panel and then the panel to the wall.
Title: Re: Seeking advice on several solar install aspects...
Post by: Journey, Roam, Explore on January 05, 2021, 02:19:52 pm
This is my layout on the roof currently taken from just behind the rear air conditioner. There's room for additional panels while still having a space to move around or I could go with higher wattage panels to replace some of my lower wattage older panels and still have room.
Title: Re: Seeking advice on several solar install aspects...
Post by: craneman on January 05, 2021, 05:01:25 pm
This is my 2030 watt set up.
final solar upgrad. (https://www.foreforums.com/index.php?topic=38155.msg369750#msg369750)
Title: Re: Seeking advice on several solar install aspects...
Post by: Jack Lewis on January 05, 2021, 11:55:49 pm
Kidspot, the links below to my approx 1800 watt system may be of help to you, or maybe to others that follow your awesum solar install.
Be careful with your high voltage, you are not dealing with a more safe 12 or 24 volts anymore.
Reply #2 3M VHS tape, brackets, wire, misc parts 2019 Adding solar (https://www.foreforums.com/index.php?topic=39928.0)
Reply #4 added used 600 W, now 1800W in 2019 for $220 Solar Upgrade (https://www.foreforums.com/index.php?topic=39455.0)
Reply #26 Calculating mixed panels 1200 W 2018 Solar Battery Charging (https://www.foreforums.com/index.php?topic=37423.25)
Pictures of my 1200 watts, 4 LG panels 2017 Shared album - John Lewis - Google Photos (https://photos.app.goo.gl/6VipJsdVWwTRJtD79)
Title: Re: Seeking advice on several solar install aspects...
Post by: kenhat on January 06, 2021, 01:51:58 pm
I have found that the sun is so low on the horizon during the winter that tilting the panels moves the needle quite a bit for us. This is with 740 watts + AGM batteries that don't charge as quickly (on our 5er).
True for me too with 720 watts. I get 9 extra amps from tilting my 3 panels. The extra amps help on those short winter days. I also park east west when possible to get the most out of the southern sun.
see ya ken
Title: Re: Seeking advice on several solar install aspects...
Post by: Kidspot on January 06, 2021, 05:26:37 pm
Thanks for the great pictures and reference links - there are some great systems out there.
btw - I realized if roof access becomes more important than power we can always remove 2-4 panels and ground mount them - the mounts will just be in place, should they ever go back up on the roof and I'll just feed them into the charge controller from the ground - been considering a remote 45 amp powerpole connection for future expansion anyway - I've got lots on hand to do that with.
Grateful for all the shared wisdom from y'all - many thanks - I started mounting the 3 charge controllers yesterday to a big piece of aluminum (From the old TV mounted up front) to help with heat dissipation. and hoping to start getting the other components installed inside next week so they are ready for the panels & batteries - I'll keep you posted of the progress (I'll start a new thread for the actual project)
Thanks again, Tim
Title: Re: Seeking advice on several solar install aspects...
Post by: Jack Lewis on January 15, 2021, 06:43:49 pm
This is an update to my reply #27 in this thread. After seeing the following video of a solar fail, I wanted to post what I noticed when I did my install. Also please note I recommend nothing in the following video except, to see how not to install brackets. It includes a good warning to definitely use larger washers, and also shows a possible shortcoming of using too few inexpensive aluminum brackets compared to the more expensive stainless steel brackets sold by AM Solar.
All VHS is not the same, do your own research. It is easy to find the 3M spec chart for various VHB 3M tape, which I checked and 4950 excelled in adherence. Also AM Solar used 4950, included with the stainless steel brackets I purchased from them. I used a combination of the brackets, Eight less expensive aluminum brackets on each panel in the rear, with large backing washers, and six stainless steel on each of the front panels, as I did my solar install over a period of two years. This you can see in my previous reply #27 in this thread. The front two panels are mounted using six brackets each of the stainless steel AMSolar brackets I did this following their recommendation because of the size of the panels I used. After seeing this video below, I am glad I did. I used primarily VHB 4950 tape only. I use screws only on the center, side brackets of the front two panels, as they due to the curvature of the roof there, appeared to need them.
He admitted failure due to using only eight brackets total, to hold down three panels, that is fewer than three per panel, which created nothing less that a big sail to be ripped from his roof. Stainless steel would have helped, however even AM Solar recommended not using too few brackets.
3M 4950/WI15 Scotch 4950 VHB Tape: 1" x 15 ft, White Amazon.com: 3M 4950/WI15 Scotch 4950 VHB Tape: 1" x 15 ft, White: Industrial... (https://www.amazon.com/dp/B00CC14L96/ref=cm_sw_em_r_mt_dp_euIaGbQRB7PZV?_encoding=UTF8&psc=1)
My 1200W solar panels before adding another 600W. Shared album - John Lewis - Google Photos (https://photos.app.goo.gl/6VipJsdVWwTRJtD79)
https://youtu.be/hCtmycZ4zZM
Title: Re: Seeking advice on several solar install aspects...
Post by: Roger & Susan in Home2 on January 15, 2021, 07:20:32 pm
Jack, the only thing that is obvious from this video is a failure to prep the surfaces correctly. When I moved one of my panels I had to cut the caulk off and use a wire saw to cut through the VHB tape and then an half hour or so on each corner to get all,of the remnants of tape off. If this guy's mounts tore off leaving. Ot VHB tape residue, even the ones with screws then they were done improperly.
Title: Re: Seeking advice on several solar install aspects...
Post by: Pierce & Gaylie Stewart on January 15, 2021, 08:02:58 pm
That's why I used a stud finder and drilled into the aluminum tubing below to mount the panels. The commercial panels should have at least three mounts on each side of the panel. That goes for the shorter 65 inch panels too.
With just two mounts on a side, if a panel lifts in the front, it will rotate up and destroy any kind of mount in the back of the panel. The middle mount really help distribute the load.