Solar Panel Installation Report

[barts]

I installed our new AM Solar panels this weekend... Almost all done aside from sticking down the second panel, as the temperature dropped too much this evening to use the VHB tape.

I installed them pretty much following directions, except that I used flex to connect the combiner box to the refrigerator vent, and I replaced the wimpy ground connector w/ a screw down lug. I tied the power lines into the main power buss (I redid all the distribution wiring on our AS this year). I mounted the controller right next to the door alongside the Trimetic battery monitor; I want to fit a plate behind the controller to protect the circuit board from stuff stored in the cabinet. Watching both meters is great - I really like having %charge readings. I also used a weathertight fitting in the refrigerator box so no combustion gases escape around the panel wire.

Hope to get some good usage numbers on our trip Memorial Day weekend....

- Bart

[Soyboy]

Barts:

That sounds great. I had a Trimetric in our last trailer and I think I am going to round things out by adding one to this setup. I have just used the 3M VHB to install the panels, they really seem like they are stuck on there and others have had success with this tape. I would prefer not to drill holes if I can get by. Not worried about leaking as much as I am about hitting a wire (even if I am careful with the depth). I my see how things go over the next couple of trips and see how the tape holds up. AM Solar seems to swear by it. ARe you going to "stick" with the tape?

On my way to work this morning, I checked (at about 7am, sun still fairly low) and I was getting almost 4 amps from my 150w setup. I thought that was pretty good. It's going be nice not having to flip the battery switch on and off when I am in and out of the trailer while it's in "storage". It will also be nice not having to run about 150ft of cord over to the trailer in order to charge the batteries up before our typical no-hookups trips.

I am very interested in seeing how it does in the "woods" over Memorial Day.

[steverino]

Also contemplating the AM solar 200W system. What's involved in mounting the refrigerator vent-mounted combiner? Do you need to take the vent cap off in order to mount the combiner on the vent and drill the required hole for the wires? Is the vent cap riveted to the roof?

Next time I bring the Airstream to the house, I need to crawl up there to see what's up. I did notice that there's a vertical vane, inboard of the vent, between the vent and the AC. Not sure whether there is enough room between the two to get a drill in there... I have no idea for the purpose of the vane, except perhaps to separate exhaust flow of the AC from the reefer..

Otherwise, I think I have it all scoped out - where the panels will mount, how to run a pair of 6 or 8 gauge from the refrigerator access to the bus bars underneath the bed in front, where to mount the controller, and how to get voltage and temp sense to the batteries.

Excellent, informative thread....

[lewster]

I usually remove the refer vent cap to mount the combiner box there. They are not my favorites, but prefer the flat roof mounted box.

The vane on the roof separates the exhaust from the A/C unit from the refer roof vent and directs it away from the refer vent so there is no downdraft created that would reverse the flow of air in the refer 'chimney'. I run the wire around the side of the vane.

[Soyboy]

Steve, I upgraded to the roof mounted combiner box so it would be easier to add panels in the future. The vent is riveted on and I used a trick I read on here to remove the rivets. I used a chisel and hammer, with about 5 or 6 taps the heads popped cleanly off the rivet. By keeping the chisel flat I didn't mar the alum on the vent cap. Don't know if I would want to try this on a more visible part of the trailer unless I had more experience!

I have not riveted the cap on yet as I want to drill a hole in the side of the vent stack and add a strain release grommet. As it is raining, I have duck taped it on to dover the vent stack for the time being (of course I won't tow until I have it secured). Then I will pop rivet the cap back on (I am not investing in an Olympic system for 8 rivets). Per Lew's advice I will coat the rivets with Dicor sealant just in case.

Just allow yourself some time to run the wires. Depending on where you are going and how you have to get there, it could take some planning (which it sounds like you have started) and dis-assembly. Just be patient.....unlike me!

[barts]

I ended up w/ the roof mounted box (my mistake), but I still ran the wires down the fridge vent. I drilled a 13/16" hole in the interior (vertical) portion of the vent, and ran a short length of (PVC?) flex from there to the roof mounted combiner box.

I do plan on "sticking with" the tape :-).

The wires go down the vent, behind the fridge, sideways behind the pull-out pantry, up into the large pantry, and through the overhead compartment to the controller.

Including plugging the hole for the old analog antenna, removing the antenna stand, etc. and installing all the wiring, it took two days worth of fiddling to install the panels. It would go a lot faster the second time, of course.

- Bart

[UAPachyderm]

I'm loving this thread.

[lewster]

Originally Posted by barts

I ended up w/ the roof mounted box (my mistake), but I still ran the wires down the fridge vent. I drilled a 13/16" hole in the interior (vertical) portion of the vent, and ran a short length of (PVC?) flex from there to the roof mounted combiner box.

I do plan on "sticking with" the tape :-).

The wires go down the vent, behind the fridge, sideways behind the pull-out pantry, up into the large pantry, and through the overhead compartment to the controller.

Including plugging the hole for the old analog antenna, removing the antenna stand, etc. and installing all the wiring, it took two days worth of fiddling to install the panels. It would go a lot faster the second time, of course.

- Bart

Well,

Welcome to MY world! (or at least a part of it!!!)

[Soyboy]

Bart: I agree, the actual, pure installation is no big deal, it's the wiring pulling and general fiddling that takes up most of the time. It's like the time I have spent trying to find a grommet (had to go to a Grangers Industrial supply place to find one) to run the wire through the vent stack and give it some support (I am sure that many just cut a hole in the screen and feed it down the vent, which works ok I am sure, but me, well I am a bit..("A" word) ...you know, about these things :-) ).

BTW, this brings up an installation point, if you are feeding down the stack and want to drill a 1/2" hole in the side of the stack to secure the wire, ask for an extra nylon strain relief connector if ordering from AM Solar. When you order the kit, they send you ones for the C Box, but not the stack. At Lowe's etc. you will only find metal ones that I would think should not be used against the alum of the stack. Also, if you don't have a 1/2" bit, just go to Harbor Freight they have some decent "step" bits for under $20 that will get the job done. Perfectly fine unless you are a pro using them to make a living.

Dennie

[barts]

Originally Posted by Soyboy

Bart: I agree, the actual, pure installation is no big deal, it's the wiring pulling and general fiddling that takes up most of the time. It's like the time I have spent trying to find a grommet (had to go to a Grangers Industrial supply place to find one) to run the wire through the vent stack and give it some support (I am sure that many just cut a hole in the screen and feed it down the vent, which works ok I am sure, but me, well I am a bit..("A" word) ...you know, about these things :-) ).

BTW, this brings up an installation point, if you are feeding down the stack and want to drill a 1/2" hole in the side of the stack to secure the wire, ask for an extra nylon strain relief connector if ordering from AM Solar. When you order the kit, they send you ones for the C Box, but not the stack. At Lowe's etc. you will only find metal ones that I would think should not be used against the alum of the stack. Also, if you don't have a 1/2" bit, just go to Harbor Freight they have some decent "step" bits for under $20 that will get the job done. Perfectly fine unless you are a pro using them to make a living.

Dennie

My step bit wouldn't fit under the vent, so I used a 13/16" twist drill I've done machining for fun for 25+ years, so between the lathe and the Bridgeport I'm pretty well tooled up :-). If I'd been really taking it easy, I'd have machined an extension for the step drill bit - I may do that anyway. The flex fitting (plastic) takes the place of a grommet. Next weekend I'll snap a picture.

Home Despot has plastic weathertight fittings (gray, not black).

- Bart

[Soyboy]

Guess I should have gone to HD instead of Lowes for the extra grommet, but I have what I need now thanks to Granger Supply. I still have to dril the grommet hole, I'll see how that goes with the diffuser shield in the way! Likely another 5 minute job that will take 2 hours LOL.

Supposed to be awesome weather here on Saturday (after over a week of clouds and rain. I hope to wrap / tidy everything up then (hole in vent with grommet, re-rivet vent cover (pop rivets covered with Dicor FYI) circuit breaker, fasten wires to roof, Dicor everything.

Can't wait to see how it does next weekend up at Cunningham Falls SP here in MD (point of reference, same park system that Camp David is in). Although the campsite is up on the mountain, in the woods, I think it has enough open area for the PVs to work (and hopefully it won't rain). If need be, I'll fire up the Yamaha.

[Soyboy]

Got it all buttoned up this weekend. With the vent lid off, I was able to easily use a step drill from the inside of the vent stack drilling out towards the middle of the trailer. I couldn't drill from the outside in on that side because of the baffle. I used butyl tape between the cap and the trailer roof and reinstalled it with pop rivets. I then covered it with Dicor, should be good for a long time.

I took some photos, now I need to get them squared away and posted. We'll see how it works out this weekend camping. Forecast doesn't look too solar friendly! I'll have the Yamaha standing by. It will be interesting to see what happens. It's working great out back keeping the batteries charged though. It's nice being able to leave the vents open (Fantastic Fans with rain detectors), keeps the trailer aired out. It's also great keeping the batteries topped up and ready to go. No more 100'+ extension cord deployments.

[barts]

I finished our installation as well this weekend, getting the last panel taped down. Even on a somewhat overcast day, we're seeing 7.5 A of charging current (well, when I put some load on the batteries, anyway ). We'll have our first trip w/ them installed this coming weekend; with any luck we'll have some sunshine but w/ this crazy spring, who knows?

We'll be on solar only for 10 consecutive days at Burning Man (arriving early, leaving late ) , so we should get a good test. Last year I borrowed panels and had them balanced on top of my truck; I'm really liking have proper battery monitoring technology now rather than trying to guess from voltage.

- Bart

[eheffa]

Congratulations, Bart & Dennie on your successful installations. It's a pretty satisfying modification I think, as it really fundamentally changes how you and where you can plan to camp with the unit. You still have all these lovely conveniences of the Airstream package but in a lot more primitive locations.

Have fun guys. ( You shouldn't lack any sun at the Burning Man.)

-evan

[steverino]

I completed my solar installation this weekend; like all projects, not everything went according to plan, but I think it went well. Today I let the system charge the batteries; when I got home this evening it was in "float" mode. I'll get a better idea on it's performance next time I take the rig out.

I selected the AMSolar SunRunner 45/4, with 3 100W panels. The panels are mounted across the roof just forward of the air conditioner, similar to eheffa's arrangement. As the 27FB has sufficient roof real estate forward of that to add at least two additional panels (one each side of the fantastic fan), I sized the controller and cable (4 ga.) to accommodate that in the future.



The big black wingbolts will go, in favor of stainless steel hex bolts.

A roof mounted combiner box is used to connect the panels to the down cable, which runs down the refrigerator vent, and through the cabinetry street side. The cable exits the bedroom bulkhead at the floor on the streetside wall, runs through the nightstand to the storage locker under the bed, where the controller is mounted, right next to the 12v bus bars. The cable is enclosed in a plastic wiremold raceway as it runs along the edge of the floor; i wish I could have concealed it completely, but I hope as we live with it, it will blend in.



One wrinkle - although I found the (inadequate) 10 ga. solar prewire, the factory omitted the RJ-11 controller prewire from the bus bars to the micropulse monitor in the galley. So I ran the RJ-11 alongside the 4ga, and mounted the monitor high on the living area bulkhead above the TV. I like the location, but for anyone else considering this placement, beware the refrigerator duct in the back half of the cabinet. I nicked the corner of it while cutting the hole for the monitor panel, requiring me to repair it with some foil duct tape.


All in all, a fun project. This thread was immensely helpful in planning the project. Looking forward to seeing how the system performs out on the road....

Steve

[UAPachyderm]

Steve, just curious... What type of batteries do you have? Also, do you have an inverter?

[steverino]

Still have the original SRM24 flooded cells - eventually I may swap those out for AGMs. As far as inverter, I've just got a small 200w inverter that I plug into one of the DC outlets to power television, or recharge other electronic gadgets.

[UAPachyderm]

Originally Posted by steverino

Still have the original SRM24 flooded cells - eventually I may swap those out for AGMs. As far as inverter, I've just got a small 200w inverter that I plug into one of the DC outlets to power television, or recharge other electronic gadgets.

Cool ... enjoy your solar!

[eheffa]

Originally Posted by steverino

I completed my solar installation this weekend; like all projects, not everything went according to plan, but I think it went well. Today I let the system charge the batteries; when I got home this evening it was in "float" mode. I'll get a better idea on it's performance next time I take the rig out.....

All in all, a fun project. This thread was immensely helpful in planning the project. Looking forward to seeing how the system performs out on the road....

Steve

Nice work Steve.

Thanks for the pictures & detailed explanation.

It is a great help to have the panels in place keeping the batteries charged & ready to go. It is also very freeing & opens up many more options to be able to go to unserviced campsites & not have to worry about power issues.

Let us know how you find it in action.

-evan

[mello mike]

Originally Posted by steverino

Still have the original SRM24 flooded cells - eventually I may swap those out for AGMs. As far as inverter, I've just got a small 200w inverter that I plug into one of the DC outlets to power television, or recharge other electronic gadgets.

Your installation looks terrific, Steve. Great job. However, with three 100 watt panels on your roof you have lots of excess power being wasted by having only two Size 24 batteries to store all of that power. You really should consider upgrading to two Size 27 AGMs, at the very least. In fact, with three 100 watt panels you are generating enough power for six to eight Size 27 batteries.