Miles Flansburg wrote:Keep me updated , might need to bugout someday.
Dan Steinicke wrote:Sounds very interesting. Sent you a "purple mooseage".
Dan
Opal-Lia Palmer wrote:Yes, yes, yes. Love it. Looking at the same states. Please email me let's talk. Opal.althoff@gmail.com
Carl Nystrom wrote:Sorry, I had an antsy toddler climbing on me when I was trying to write my last post, and now that I look at it again, I see that I was looking at the circuit backwards. In your picture, the charge controller is connected without ANY fuse between it and the battery. If the charge controller were to have a catastrophic failure (and they do happen) the batteries would push so much current through that wire that it would turn red-hot and catch on fire. Fuses. Must. Be. On. Every. Wire.
Here is a demonstration of what happens when you short circuit a battery:
https://www.youtube.com/watch?v=xESCXFz8ZQE
I am not really sure why a system of this size would have a 300Amp fuse in it to start with, but if you intend to use it, I would make something that looks like this:
The main fuse protects your main battery leads: if you drop a wrench between the two bus bars, it will open if 300 amps flow, and since all the parts are rated for 300 amps, you will be replacing the fuse, not everything that burns down in the resulting fire.
If the charge controller gets fried: the 30 amp fuse will blow before the 12ga wire is melted, since 12ga can only sustain about 30 amps
If the inverter shorts out, same thing, the fuse protects the wiring.
If it were me, and I was not thinking of major upgrades down the road, I would probably scrap the 300A fuse and put in a 100A fuse directly to the inverter.
Busbars are nice to have if you want to add more circuits later, and you might find that you want to add a battery charger to use a generator, or some 12volt circuits to run a few lights without the inverter or whatever.
Edit: Also, oversizing the wire relative to the fuse is fine electrically: if you want to run 6 ga wires on a 30A fuse, go for it. It reduces voltage drop, but on short runs like this there is really not much point. The wire costs a lot more, so generally, just stick to whatever the chart you are using tells you. I personally would run 10 ga wire for 30 Amps, but 12 would i am sure be okay in this application.
Michael Fundaro wrote:I had zero experience with solar when I installed the solar panels on my trailer. After a couple weeks of research online of available kits I ordered the one I liked and using their easy to follow instructions I installed it myself. It was not difficult at all, aside from the fabrication of the frame on the roof of the trailer which I figured out myself. I mounted the solar panels to the roof, flat, using 2" square aluminum tubing so the panels sat flat and they have handled 90mph speeds on the freeway without any problem. The plus side to this is the solar panels shade that portion of the roof and it is considerably cooler on that portion of the ceiling compared to the rest of the trailer.
If you have any DIY abilities I believe you can install a solar system yourself. Usually the manufacturer has videos on how to do the connections. You can pay someone to do this for you but you could save a munch of cash doing it yourself. Even if mounting the panels on a pole in the yard it wont be very difficult. The hardest part will be digging the hole for the mounting post.
Carl Nystrom wrote:
I guess this is just a way of using less wire to make the connection and is not providing any protection to the battery?
Using one lug of a component to connect multiple connectors is done all the time, but in this case it is very sloppy. The fuses are there to provide protection for the wires. EVERY wire that connects to your battery must be fused to protect it FROM the battery. If your charge controller fails (and if I recall correctly, they tend to fail as a short circuit) then the battery will try and push more than 300Amps through it. A single lead acid battery can push 500+ amps at below freezing temperatures.
In this configuration you would need to size the wires to and from the controller to handle 300A, so probably at least 2/0 copper (dont forget that the return path will also carry the same current). It looks like the wire on there is fairly beefy, and seeing as it is in open air, and pretty short, I would guess that the fuse would blow before it caught your plywood on fire. But that is just a guess from a stranger on the internet, so its worth what you pay for it. Still, much better would be to have Battery -> 300A fuse with 2/0 -> Busbar (capable of handling 300 Amps - this is why you dont do 12 volts, kids) -> then from there you put another fuse that is sized for the smallest wire that will carry at least the full rated output of your controller. What is that on there, like 4awg maybe? If so, it should be able to carry like 95Amps if it has 90 degree C rated insulation.