Another Solar Setup

Many thanks to all you folks who helped me work out the details of my solar installation. And for the many examples of your craftsmanship.

This link to some pictures may work:
Picassa Album "Solar Trailer"

Some info:
Two 195W panels from "Sunny Power", 32'x60", Voc=44V
Connected in parallel with 2 MC4 Y connectors.

Mounted with double Al 6" angle, 3 SS screws, 3M5200 sealant/adhesive.

Panels at rear of trailer, 10ga cables run on roof to the front. Found a water-tight exterior electrical box to cover the hole through the roof to the interior cupboard. Drilled a hole in the bottom and two in one side for the wires. Screwed and glued (3M5200) in place. The two wire pass-thrus have rubber o-rings, maybe for cable TV? Fit the wires perfectly.

Run wires inside to bottom of front, side clothes closet just over the trailer's pass-thru. "Baby" breaker box with 15A Solar and 30A Battery breakers (Midnite Solar). Rogue 3048 MPPT. 6ga down to trailer pass-thru where it joins up with a PD9260 charger with convenient double bus. Then down and out to batteries on the trailer tongue.

(This is strictly a battery charging circuit, solar or 110V; there are no external loads. The original WFCO remains as the converter.)

Ground to frame from all boxes, Temp and Voltage sensor wires follow same path.

Seems to be working fine so far ... :)

Biggest problem? When bolting the Al angles together and to the Solar Panel frames, about 50% of the "cheap" SS locknuts from Home Depot would jam almost immediately and have to be hack-sawed off. Eventually gave up, returned what was left and used standard zinc-plated bolts, nuts & lockwashers. If I ever get over the trauma, maybe someday I'll replace those with SS.

Sources:
- Solar panels, MC4 connectors, wire with MC4s picked up at 2solar.ca, Markham ON
- Rogue MPPT shipped from Rogue in Oregon
- "Baby" breaker box and Midnite Solar breakers shipped from Arizona Wind&Solar
- 6ga wire, connectors, misc. electrical shipped from DelCity USA
- 3M5200, battery bolt-on fuse holder and 60A fuse PU from WestMarine
- Al angles, screws and bolts PU from Home Depot

25 Replies

RJsfishin
Explorer
Jul 07, 2014
Quote:
Biggest problem? When bolting the Al angles together and to the Solar Panel frames, about 50% of the "cheap" SS locknuts from Home Depot would jam almost immediately and have to be hack-sawed off. Eventually gave up, returned what was left and used standard zinc-plated bolts, nuts & lockwashers. If I ever get over the trauma, maybe someday I'll replace those with SS.
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SS bolts just love to "gall", meaning the bolt is just waiting to tear in to the nut and become the same as a welded "1 pc". Not many know this, but the proper way to bolt SS, is to use antiseize on the threads. That will completely eliminate the seizing and galling.
The SS bolts you purchased were regular run of the mill, w/ an average strength of a little more than a grade 2, but adequate for what you're doing. You can buy SS bolts that will have grade 5-8 strength, but hard to find, and very expensive. But they will still gall, and must be used w/ antiseize.
brulaz
Explorer
Jul 07, 2014
BFL13 wrote:

...
controller to converter/DC panel wires where the converter is under the fridge, and then miles of wire to the batteries somewhere. Not ideal!

If the converter is a deck mount near the battery bank then it is good to share the wires with it or with anything else there like an inverter. You can have a positive "buss" to collect all the wires from solar , converter, inverter, and use the Trimetric shunt as the negative buss.

Just to clarify, that PD9260 is not used as a converter, only as a charger. The original WFCO is still in place and used as the converter when plugged in to 110V. The batteries are then switched away from that loads circuit, and either the solar or PD9260 is used to charge them via the charge circuit which is 6ga from the Rogue, to the PD9260, to the batteries with <2% voltage drop IIRC.

But I'm not sure if I'll ever use the PD9260 again, as the Solar Panels/Rogue are doing so well. Maybe after a draw down in winter with cloudy weather, and the next stop has 110V. Anyway, I had it from the old trailer, so popped it in. :)
brulaz
Explorer
Jul 07, 2014
McKenziek wrote:
Did I understand correctly that you ran the 6 gauge from the controller to your Intellipower chargers secondary posts instead of directly to the battery? Thats something I didnt consider in my install and would've saved me some .cable.

Yes. And it saved some cable as you say.
They are just simple bus bars on the PD9260.
BFL13
Explorer II
Jul 07, 2014
McKenziek wrote:
Did I understand correctly that you ran the 6 gauge from the controller to your Intellipower chargers secondary posts instead of directly to the battery? Thats something I didnt consider in my install and would've saved me some cable.

That can be in conflict with the value of having the controller-battery wires of low resistance (short and fat) depending on the location of the converter or DC panel battery lugs.

Some installations go there when they put the controller inside where it can be seen and its buttons pushed. Solar panel to controller wires down the fridge vent, controller on wall beside the fridge, controller to converter/DC panel wires where the converter is under the fridge, and then miles of wire to the batteries somewhere. Not ideal!

If the converter is a deck mount near the battery bank then it is good to share the wires with it or with anything else there like an inverter. You can have a positive "buss" to collect all the wires from solar , converter, inverter, and use the Trimetric shunt as the negative buss.
McKenziek
Explorer
Jul 07, 2014
Did I understand correctly that you ran the 6 gauge from the controller to your Intellipower chargers secondary posts instead of directly to the battery? Thats something I didnt consider in my install and would've saved me some cable.
brulaz
Explorer
Jul 07, 2014
OK, here's an update. Bottom line is I'm very happy with this setup so far.

Admittedly, it is summer and the days are long, and once setup we don't use many amps. But it's windy, rainy and cloudy today, so we are spending more time inside. And the solar panels are only giving me 25-50W in MPPT.

But that seems to be enough to charge up the computers and tablets, and run the 3G antenna amp for internet access. I also have a handheld 75W inverter for my coffee grinder, but that's all the 110VAC we use. The water pump and electric awning are run occasionally.

During initial setup, the electric tongue jack was run and up several times (use it to help remove the tension bars), the electric stab jacks set and the slide opened. There was a bit more sun then with maybe 100W from the panels, so the batteries were quickly recharged afterwards.

All the 12V electrical do-hickeys on this trailer were the reason we decided to go solar, and it does seem to be doing the trick. But the real test will be next November when we spend 3-5 days at Great Smokey Mountains National Park. The leaves will be off the trees but they don't call the mountains "Smokey" for nothing. And it gets cold then, often below freezing at night, so the furnace fan will be running. We'll see. At some point I'd like to add a second bank of AGMs to help out.
pianotuna
Nomad III
May 19, 2014
Hi,

On my previous RV, which had 30 watts of amorphous solar, the "charge" light would glow at about 1/2 brilliance when I was directly under a street lamp. I don't believe any useful charging happened.
2oldman
Explorer II
May 19, 2014
mchero wrote:
Is it possible to be parked under a street light, e.g. Wal-Mart parking lot and have yor panels put out usable voltage?
Not that i've ever heard of, but not to say it isn't worth a try.

Check it out ..Google: solar streetlight
brulaz
Explorer
May 19, 2014
mchero wrote:
Is it possible to be parked under a street light, e.g. Wal-Mart parking lot and have yor panels put out usable voltage?

Dunno, sort of don't think so. But it would be hilarious if you could. And some of those parking lots have a lot of light.
mchero
Explorer
May 19, 2014
Is it possible to be parked under a street light, e.g. Wal-Mart parking lot and have yor panels put out usable voltage?