Extra solar panel and a led lightbar on AI

[djjoonie]

Here are the photos of the RB lightbar with solar panel mount installed on my 2012 AI the Sunexplorer now reads about 8.5 amps when sunny from 3-4amps with 1 panel before.

[Titus]

Looks light your new panel used every available square inch of space - good job. What is the black piece at the front of the panel? Some sort of airfoil?

Did you move/remove the Sirius antenna, or was it located someplace different on your model?

[djjoonie]

Originally Posted by Titus

Looks light your new panel used every available square inch of space - good job. What is the black piece at the front of the panel? Some sort of airfoil?

Did you move/remove the Sirius antenna, or was it located someplace different on your model?

Thank you. the black piece at the front is the LED light bar
If you are referring Sirius antenna to the little white bump on the top of driverside roof, we had to modify and cut the solar panel bracket to make it fit.
Now I know what that white bump is

[FlyFishinRVr]

Originally Posted by djjoonie

Here are the photos of the RB lightbar with solar panel mount installed on my 2012 AI the Sunexplorer now reads about 8.5 amps when sunny from 3-4amps with 1 panel before.

It will read even more if you replace the truly awful Sunexplorer (aka Atkinson) with a MPPT charge controller (Renogy, Victron, etc).....

[Pahaska]

I installed the new Blue Sky solar controller in a nice box, laminated to match the interior. It is in the space vacated by the bed extensions that were removed when I converted to twin beds. I used all #10 wire between the controller and the electronics, both for the solar and for the battery feed. That's where I hit a surprise.

The Airstream manual shows #10 wire from the solar panels to the solar controller and ground. At least the accessible parts of the solar wires in my AI are #14 at the very best, both the + solar wire and the ground. Everything else is hidden, so I don't know whether there is any #10 at all in the factory wiring.

The new controller seems to be working well. I am getting some charge in the shade under the roof of the storage shed with the sun directly overhead.

Forgot my phone today. I'll post photos tomorrow.

[Titus]

Pahaska,
I pulled 25' of 8ga cable from the 200W of solar panels down to the controller. But found that the recesses for the screws on the controller were too small for 8 ga wire so had to trim off a few strands of wire to get them to fit on the controller.

[Alex AVI]

Originally Posted by Pahaska

That's where I hit a surprise.

The Airstream manual shows #10 wire from the solar panels to the solar controller and ground. At least the accessible parts of the solar wires in my AI are #14 at the very best, both the + solar wire and the ground. Everything else is hidden, so I don't know whether there is any #10 at all in the factory wiring.

JOHN - Please clarify above observation. AS only represents in their diags #10 from PVs to solar cont. input (Red) & PVs to batt. Gnd (Green). They represent #12 from solar cont. to 50A batt. brkr bus bar (Red/Wht) and #12 from solar cont. to Gnd buss bar (Blk). Are you sure you were seeing the wiring from the PVs and not the skinnier #12 coming off of the controller?

[Pahaska]

Originally Posted by Alex AVI

Are you sure you were seeing the wiring from the PVs and not the skinnier #12 coming off of the controller?

Again, I walked off this morning with my phone, so no photos.

No, I am describing the feed from the roof and it is no larger than #14 and it is some sort of super flexible wire. I doubled it back to better crimp into my #10 using yellow crimps. It comes out of the wall below the rear RS window with the specified yellow and green wires. The wires are no more than #14, and are super flexible.

I spent this morning removing the electronics compartment door and pulling out the breaker panel out far enough so that I could remove the old solar controller. The only way I can reach it. No way from above.

The yellow wire ran to the solar controller. The green wire ran to ground. My new controller requires both the + and - wires from the roof and has a separate pair of wires to the battery. I used #10 for these four connections in a bundle that runs from the electronic area back to the head of the bed and then up to the controller that is mounted at the end of my shelf in the area vacated by the bed extensions.

There are two #12 wires coming off the controller, but they are short and are potted into the controller. The solar + is crimped to the roof feed maybe a foot from the controller. The +12 out is #12 and is about a foot long to a buss on the sidewall of the compartment. The potted ground wire from the solar controller is about a #16 black wire. This black wire is crimped into a larger white wire close to the controller which then runs to ground.

Getting access to the solar controller would not be bad in a Lounge, but it is a nightmare with the twin beds because there is so little clearance between the beds. Glad that job is done. Anybody need a slightly used solar controller and remote display?

On edit. The solar feeds from the roof have tags on them. I forgot to mention that.

[Boxster1971]

This discussion once again shows that Airstream does a very poor job of installing solar systems on their vans.

[Alex AVI]

Originally Posted by Pahaska

Again, I walked off this morning with my phone, so no photos.

No, I am describing the feed from the roof and it is no larger than #14 and it is some sort of super flexible wire. I doubled it back to better crimp into my #10 using yellow crimps. It comes out of the wall below the rear RS window with the specified yellow and green wires. The wires are no more than #14, and are super flexible.

I spent this morning removing the electronics compartment door and pulling out the breaker panel out far enough so that I could remove the old solar controller. The only way I can reach it. No way from above.

The yellow wire ran to the solar controller. The green wire ran to ground. My new controller requires both the + and - wires from the roof and has a separate pair of wires to the battery. I used #10 for these four connections in a bundle that runs from the electronic area back to the head of the bed and then up to the controller that is mounted at the end of my shelf in the area vacated by the bed extensions.

There are two #12 wires coming off the controller, but they are short and are potted into the controller. The solar + is crimped to the roof feed maybe a foot from the controller. The +12 out is #12 and is about a foot long to a buss on the sidewall of the compartment. The potted ground wire from the solar controller is about a #16 black wire. This black wire is crimped into a larger white wire close to the controller which then runs to ground.

Getting access to the solar controller would not be bad in a Lounge, but it is a nightmare with the twin beds because there is so little clearance between the beds. Glad that job is done. Anybody need a slightly used solar controller and remote display?

On edit. The solar feeds from the roof have tags on them. I forgot to mention that.

JOHN - Thank you for confirming this. This is worrisome because they have not only used thinner, but gone 2 gauges thinner than originally spec'd. Even though I have no urgent need to replace my solar controller (it works & I do not depend on solar) I will still check my unit to see what gauge wiring they used.

[Titus]

I kept the old 50W panel and Atkinson controller after my upgrade. Not sure why. I'll give them to somebody for the price of postage, though I am not sure they are worth the postage.

[Alex AVI]

Missed Edit window:

Dug up Engineering Electrical Diagram #513265, date code 02/2017
1. Solar (+) pre-wire YELLOW/Blk M4c1(PV to controller) - #12 gauge
2. Solar (- )pre-wire GREEN/WHT M4c2 (PV to Gnd buss) - #12 gauge

So, conflicting info from my 2018 User Manual basic solar schema to actual wiring diagrams in the actual Engineering Drawings. I guess this only means AS deems it safe to run #12 gauge from 300 watts and (as we all know) the info did not make it to the User Manuals.


Ok, so if we get wonky on our numbers, consider 3 electrical datapoints:
1. US electrical codes max current for #12 gauge wire to be 20A.
2. But #12 gauge copper is capable of much higher.
3. The 'Fusing Current' at which a wire will melt is a little over 230A for copper.

So if wiring anything other than residential or commercial building that has to meet code, , the choice of wire gauge boils down to I2R (or EI) power losses you are willing to tolerate below the Fusing Current. This happens a lot with appliances where the inner workings of the appliance is wired with gauge less than the breaker wire gauge and is perfectly up to code.

In other words, AS is still well within specs. May not be the best gauge for max efficiency, but still in spec. FYI - 300W @ 12v yields 25A. But the Go Power max power (99.968W) @ 17.6v generates max current of 5.68A. Even at a short, it only generates 6.14A. So even if all 3 x 100W panels have a shorted load, the total would only be 18.42A. This is how some folks here (WACHUKO) are still safely able to add a 4th 100W panel. With efficiency losses, that theoretical 22.72A will be lucky to hit 18A.

PS: I am in no uncertain terms siding with AS. Just stating they just doing it cheaply and leaving the power & efficiency losses for the customer to worry about. There's no upside from their standpoint to go higher. If it was me building it for customers, I would have definitely kept the original #10 they had spec'd at one time a long time ago. If I was building for myself, I would use #8 gauge. But gotta remember, wire is also heavy, every thing adds up, which is why multiplex wiring is a necessary evil. RV manufacturers are almost like bike builders - counting grams.

[FlyFishinRVr]

Originally Posted by Alex AVI

Missed Edit window:

Dug up Engineering Electrical Diagram #513265, date code 02/2017
1. Solar (+) pre-wire YELLOW/Blk M4c1(PV to controller) - #12 gauge
2. Solar (- )pre-wire GREEN/WHT M4c2 (PV to Gnd buss) - #12 gauge

So, conflicting info from my 2018 User Manual basic solar schema to actual wiring diagrams in the actual Engineering Drawings. I guess this only means AS deems it safe to run #12 gauge from 300 watts and (as we all know) the info did not make it to the User Manuals.

How are the panels wired, series or parallel?


If they're in series, no problem as the current doesn't exceed that of 1 panel (about 5-6A for a 100W panel). This way you can keep the wire size to a minimum (thus reducing weight and making it easier to route) and by using a MPPT controller rated for the max voltage you expect to see, you can use all of that sunshine goodness......

[Alex AVI]

Originally Posted by FlyFishinRVr

How are the panels wired, series or parallel?


If they're in series, no problem as the current doesn't exceed that of 1 panel (about 5-6A for a 100W panel). This way you can keep the wire size to a minimum (thus reducing weight and making it easier to route) and by using a MPPT controller rated for the max voltage you expect to see, you can use all of that sunshine goodness......

FLYFISHINRVR - did you see my calculations further down? I did take into account how AS represents their solar diags which is parallel, which is also worse case scenario for max current. And my calculations show that even with all 3x100W panels shorted, the worst case max current going through the wiring is 18.42A (based on GoPower specs). Under normal conditions with all 3x100W panels operating optimally, the max current to be expected is 17.04A. Both max current values are below the 20A rating for #12 gauge and well below Fusing Current of approx 230A. Either way, series or parallel, I see no issue with the #12 gauge handling 3x100W solar panel output. Sure, doesn't leave much headroom when one adds the 4th panel but AS did not spec the system for 400W. And besides, none of these panels operate at 100% efficiency even brand new (at least the flex ones that I have didn't) So adding a 4th panel with all of them max'ing out at 90% efficiency yields 20.5A, hardly enough to melt the wire. I agree it may not be the most efficient way to transfer 20.5A without incurring power loss due to wire size but hardly dangerous.

If I am missing something to factor in the calculations, would love to hear more from you or others. I am no solar expert and not pretending to be Just using the GoPower published specs to figure out if AS undersized the wires or not. So far, I do not see any indications from their Engineering Diags that they did (pending my own physical inspection of my wires). However, they did undersized their wires relative to what they published in the User Manual (#10 gauge) vs. what is in the Engineering Diags (#12 gauge). That is a discrepancy that they should have corrected. It definitely confused me.

[FlyFishinRVr]

Originally Posted by Alex AVI

FLYFISHINRVR - did you see my calculations further down? I did take into account how AS represents their solar diags which is parallel, which is also worse case scenario for max current. And my calculations show that even with all 3x100W panels shorted, the worst case max current going through the wiring is 18.42A (based on GoPower specs). Under normal conditions with all 3x100W panels operating optimally, the max current to be expected is 17.04A. Both max current values are below the 20A rating for #12 gauge and well below Fusing Current of approx 230A. Either way, series or parallel, I see no issue with the #12 gauge handling 3x100W solar panel output. Sure, doesn't leave much headroom when one adds the 4th panel but AS did not spec the system for 400W. And besides, none of these panels operate at 100% efficiency even brand new (at least the flex ones that I have didn't) So adding a 4th panel with all of them max'ing out at 90% efficiency yields 20.5A, hardly enough to melt the wire. I agree it may not be the most efficient way to transfer 20.5A without incurring power loss due to wire size but hardly dangerous.

If I am missing something to factor in the calculations, would love to hear more from you or others. I am no solar expert and not pretending to be Just using the GoPower published specs to figure out if AS undersized the wires or not. So far, I do not see any indications from their Engineering Diags that they did (pending my own physical inspection of my wires). However, they did undersized their wires relative to what they published in the User Manual (#10 gauge) vs. what is in the Engineering Diags (#12 gauge). That is a discrepancy that they should have corrected. It definitely confused me.

Hi Alex. No, I didn't see that. It makes sense though that they would wire them in parallel since the Atkinson is a PWM controller and it doesn't support series configs.


Having said that, if anyone WAS concerned about wire size (due to heat or voltage drop), and was planning to go to a MPPT controller, it would be an easy exercise to reconfigure the panels to be series vs. parallel. It would certainly be easier than pulling new 6ga wire (for < 3% voltage drop) through the coach....

[Alex AVI]

Originally Posted by FlyFishinRVr

Having said that, if anyone WAS concerned about wire size (due to heat or voltage drop), and was planning to go to a MPPT controller, it would be an easy exercise to reconfigure the panels to be series vs. parallel. It would certainly be easier than pulling new 6ga wire (for < 3% voltage drop) through the coach....

FLYFISHINRVR - You know that's an excellent idea. Not sure if I will be doing the MPPT this winter, as you know we never depend on our solar YET! We kinda full hookup weenies for now. But I just got an idea from your idea which may make the wiring on the roof a little cleaner if the panels are series. Hmmm . . . thanks

[Pahaska]

I've been meaning to post a photo of my Blue Sky MPPT installation, but I kept forgetting. Today, I brought the AI home for some minor mods and to get it ready for some upcoming trips. I spent the whole day on it, and the only thing noticeable is that it is nice and clean inside. Still dirty outside, except that I did wash the windows.

The display self-dims at night so that it doesn't disturb us.

Here is my Blue Sky pulling in some electrons with the AI under the leafy shade of a live oak tree.

On edit: I forgot to mention, the thing next to the solar controller is a trolling motor socket. I splices a mating plug to my compressor. This location makes use of the heavy wires to the battery.