Kentucky cabin on solar

[markandsherry8591]

   We have been planning on starting a post on here for a little while now... thought it was time to quit being lazy and go for it  We sold our paid off 1500 sq. foot house with 13 acres in August to have a fresh new start in life and bulid a smaller cabin with some flatter land and to be totally off the grid. Our family thinks we have gone a little crazy and can't even picture anyone staying in the woods in a camper with 2 small kids, a dog and a cat.  We just bought 10 acres in Edmonton Ky. We have already started building our cabin that will be around 1200 sq. feet. I am still trying to figure out how to post pictures on here :/ -Mark and Sherry

[Rob_O]

Greetings from Louisville. Happy to see you here

This is how you post pictures http://countryplans.com/smf/index.php?topic=11663.0

[markandsherry8591]

Our home site


Our pond site

[markandsherry8591]

Here is what we have done so far on the cabin






Work on our shed





Flooring

[markandsherry8591]

Solar



We only have 8 batteries for now, we hope for 8 more before our house is done by winter... for now in Kentucky it's October 2nd and in the lower 80's still. We are not complaning!!! For now we have our camper hooked up to the solar, a few lights in the shed, our refrigerator, stove and washing machine (that's all in our shed for now).








Today's project a chicken coop! Noah must be the only one working around here!





Gotta love math homework!



Pretty Harvest Moon out here from a few weeks ago.... was too pretty not to share!

[Carla_M]

Great looking property and happy looking kids! Growing up in the country was something I enjoyed as a kid. 

May I ask some questions?  Did you design the cabin yourself? Have a floorplan to share? How big (watts) is the solar array? What's the ground like? Can you tell me about the posts and beams; how big they are and the spacing, how deep in the ground. I see so much variation in foundations.  Thanks for sharing.

[suburbancowboy]

Question on your solar set up.  How are the panels wired?  Three in parallel and then the three sets in series?  What size are they?
What size of inverter are you running?  Reason I'm asking I am installing a very similar system now.  Haven't got inverter yet.

[markandsherry8591]

Hi Carla and suburbancowboy  @ Carla- We found our floorplan off of the internet, no blueprints... just going with the floorplan







The solar array is 2.3 KW. The ground here is softer red clay. Our post are 6x6 post 3 ft. in ground

Suburbancowboy the panels are wired three sets of three- three in parallel and then the three sets. They are 265 watts each. The inverter is 4400 watts 48 volt system. The inverter is bigger than we need but we like having the extra power if we need it. Alt-e-store is where we bought most of our solor... had to call them once to figure it out and the lady was very knowledgeable and helpful!
Our battery interconnect cables are too small it's not pulling the energy equally across the batteries. We will post an updated picture soon.

[MountainDon]

Our battery interconnect cables are too small it's not pulling the energy equally across the batteries.

That statement has me puzzled.    8 batteries x 6 volts = 48 volts.  Therefore you have a series string, nothing in parallel. Right? Batteries in series can not have any unequal discharging because of wire size. That is the beauty of a series only string. The wire gauge could be too small to carry the large amperage that inverters can demand, but that would be an equal load spread down the chain. If a battery is showing less charge than others it is the battery at fault, most likely.   If there are parallel strings then unequalness can occur. It is inevitable in parallel strings as there are inequalities within batteries. Even those from the same batch can have small differences in internal resistance because of manufacturing tolerances.



FWIW....
Better than using cables to connect parallel strings is to use a buss bar system. In that, each series string is connected to heavy copper buss bars; a positive and a negative. Like this...


We also use heavy copper bars as the interconnects... less resistance than cables.

Buss bars do not eliminate any unequal resistances within any battery but it can be better than a cable system. It also makes it easy to remove a series string from the mix if the need arises for any maintenance.

[Carla_M]

@ Carla- We found our floorplan off of the internet, no blueprints... just going with the floorplan

Ah. I could be happy with just the downstairs. I have modified a floor plan I have found online. I am happy with it at present. It is actually similar to your main floor plan. Unfortunately I'm no where close to being able to build as I have yet to find property. But having that floorplan is the end of my abilities. How do you get from a floorplan to a construction blueprint? That's my problem. I think I'm going to have to hire the talents of someone for that. Then I am also going to have to act more like a general contractor and hire out large sections. But that is still off in the future. Maybe if I procrastinate enough I'll learn more or meet up with a talented builder.

I guess I was expecting to hear you had blueprints. The reason I was wondering is that when I count floor joists from one post to another I get about 10 which means 9 spaces. It is hard to tell is that is accurate as I can't really see them all. I am interpolating a bit.  If the spacing is 16", that is 144" between posts. And from what I've learned here in 2-3 years of lurking, is that is a huge span. I was wondering how you made that work; be strong enough?

[markandsherry8591]

Inside the e-pannel



Upper photo with surge protectors

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New interconnect bars

[URL=https://s1023.photobucket.com/user/markandsherry8591/media/IMG_1550_zpsdfe014ba.jpg.html]

Hammering flat the pipes for the plates Blacksmithing came in handy.

[MountainDon]

I probably should have pointed out that the buss bars I made are 3/16" x 3/4" solid copper stock. That calculates to an ampacity of 250 to 300 amps. That is way oversized for my system, but guaranteed to never cause any resistance to current flow.

Fpr anyone interested there are tables at StormCopper.

[markandsherry8591]

@ Carla- The span is 12 foot at the moment, we have steel bars reinforcing the joints. We plan to add a middle pier to each span later this week. We are also planning to add cross bracing in the comming weeks as money allows. As of the moment it looks great- no sinking or anything.
@ Mountain Don- We used heavy walled copper pipe as inter connect bars, that idea came from EaglesSJ who has helped us a great deal tweaking our solar. The cables we had before were starting to melt when we ran the AC in our camper, theses bars have not overheated yet and are working so much better.

Before




After- The copper pipe cost $24.00 I think. We have more then enough left for adding another 8 batteries. The previous wire and terminals were $32 and were undersized- the ones close to the middle melted- were smoking!

[Carla_M]

@ Carla- The span is 12 foot at the moment, we have steel bars reinforcing the joints. We plan to add a middle pier to each span later this week. We are also planning to add cross bracing in the coming weeks as money allows. As of the moment it looks great- no sinking or anything.

Thanks for responding.  Not sure I follow what is meant by the "steel bars reinforcing the joints"? I have seen steel plates sandwiched between two wooden members.     What size are those side beams the joists hook up to? 

I would truly hope nothing has sunk at this early stage.    What sort of a footing did you use in that clay?

FWIW, I would add the posts and all the bracing before going any further along. Somewhere on this forum is a tale of woe around a cabin that was dried in before any bracing was installed. And then it was too late.

EDITED  In AR I think.

[Carla_M]

Nope. It was KY.  Georgetown.    http://countryplans.com/smf/index.php?topic=4952.msg82920#msg82920    Wouldn't want to see that happen with yours.

[markandsherry8591]

Yikes! That is scary... but from what I am getting out of their situation is drainage issues followed by gravel in the post. Our post are concreted in with no drainage issues (and we had almost 4in. of rain the other night). Not sure it has anything to do with spacing 

[Don_P]

The cause of that failure was tall unbraced posts. The soil conditions allowed the demise to happen quickly but were not the cause. If the posts are not mechanically braced then the soil is providing the bracing for the structure, more posts = more bracing (this is not a good way to build as we are not soils engineers though)

I believe I'm seeing a single rim joist rather than a built up girder between posts, the wall sheathing is not tieing the wall to the floor from what I can see. Ideally the wall sheathing ties the walls and floor(s) together. Right now you look to be very lightly loaded on the floor, which is good, but as the floor becomes loaded, if what I'm saying is correct, the floor can deflect and seperate from the walls at the bottom plate and open up a gap. If what I'm saying is correct an additional beam inside the posts under the joists, with the additional posts in place, and then 2x6 scabs on the inner face of the 6x6 posts under that bolted on dropped beam to support it down to the concrete would be a good idea. The post face of that beam would also provide good nailing or bolting for the upper end of bracing that runs to the posts. Hope this helps.

[Squirl]

I was just looking it over, and I think I see what Don sees.  From the first picture looks like you end nailed the floor joists to the rim joists.  I can see three end nails where each of the joists are. I don't see any girder.  Post and pier foundations require girders.  A single rim joist is not sufficient, regardless of the span between posts.  Maybe we are seeing something that was later changed or misinterpreting a picture. 

Because it was the most commonly misunderstood issue I have seen over the years, I did a short guide to reading girder sizing charts.

http://countryplans.com/smf/index.php?topic=10511.0

From a quick read of the charts, four 2x12s can't span more than 9 feet in this situation. My belief is a single joist spanning 12 feet would likely be in the catastrophic failure zone. Don_P is better at specifics in the "bend far vs. break" department.

[phalynx]

Don_P is a master for sure.  That KY home was unfortunate.  I visited him and his wife shortly before it happened.  That land was a very soft clay and they had a lot of rain.  That caused the house to shift.  It was able to happen, like Don_P said, because there was no bracing for the tall posts.  It was sad and he was scared.  His house was fixable but he was so turned off by what happened that they tore it all down and built a very small cabin on the property.

The key here is to fix the beam problem now.  It doesn't look like you have a full load on your house so with some careful planning and some jacks, you can install some beams.