This day has been a long time coming! I’m officially stealing power from the sun!
2 nights ago, I finished the hardware installation and turned it on right at dusk. Yesterday morning, I woke up excited to see how it was going and was frankly, very, very underwhelmed. The batteries were full and the panel output was very minimal because of the smart controllers.
I ran 2 air conditioners for a few hours, hit high noon, and things were rocking and rolling, stealing power from the sun.
If you want to see a video of the storage bay/equipment area and a few boring videos of voltmeter readings from each rack of panels, check this post on Imgur
. Their movie links don't translate well and don't play in the browser unless you're on their site.
Now, let’s look at that hookup a little better. Each rack/size of panels on the roof are split in half with them wired together in series. I then take those series sets and take them each to their own combiner box.
Coming out of the combiner box, I drop down through the roof, down through a floor to ceiling cabinet, and then directly into my equipment bay/storage hatch.
I come directly to these circuit breakers. A couple of things:
1, in the RV world, it’s common to only switch the positive connection and not both. NEC and ABYC standards say you should do both. I’ll be changing my breakers out so that I can switch both.
2, my wiring connection on the right is kind of crappily done because the breaker doesn’t accept a size 2 wire going into it. I had to trim the strands so it fit and it’s not as clean + tidy as I’d like.
The circuit breakers are there so I can “turn off” the panels as needed. You should never have a solar controller with power coming into it with no batteries to go to. It can damage the controller. So, this lets me turn the panels off.
Coming off of the breakers, I feed into the solar controllers. The big panels are red + black wires, size 2 awg. This was recommended to me by the vendor who sold me most of the solar hardware and the small panels. Personally, my math says it’s overkill. But it works.
The small panels are 6 awg and are orange/black. Why orange? No idea. That’s what they sold to me.
Coming out of the solar charger, I want to be able to disable one or both from my electrical system. The black + yellow 40A and 120A circuit breakers let me do that. These also act as a safe guard in case bad ever happens. But that’s also a bit of belt + suspenders protection as I have fuses in that Lynx Distributor box.
Speaking of that Lynx Distributor, let’s take a look under its dress, so to speak. This is just a fancy pair of bus bars + integrated fuses. I have the smaller controller fuses at 40amps to protect the wires (always fuse at less than the wire rating) and the big controller at 125amps.
Can I be honest for a second? I worked with the rest of the system up and live and while I love my Lynx Distributor, I was nervous as well working in such a tight place. I really should have just cut power for a bit.
Now, let’s start looking at some of the output. These are the big panels. This wasn’t the highest output I saw yesterday- just so happens to be what I have a saved screenshot from.
And now for the smaller panels. I only have 5 of my 6 panels as one came with shipping damage. I have them in 2 series sets- one of 3 panels and one of 2 panels. Series adds the voltages up of each panel.
Those 2 sets are then wired in parallel. When wiring in parallel, the lowest voltage controls the output. So since I have just 2 panels on one set, it’s effectively like I have 2 panels on both sets.
Longest story shortest, it’s like I only have 4 panels hooked up. Adding the last one will be like gaining 2. *magic*
The Victron Connect app is where I go to see my solar universe. I’m able to see output watts of each set of panels. As you can see here, I was pulling in a total of 2,310 watts from the sun and recharging the batteries.
The day’s production.. It’s very interesting to see how the output jumps around based on clouds, shadows, battery state of charge, and all the things.
And now, a look at my real mess. This is the battery bank. It’s currently setup for only 1/2 of the batteries (left side currently). It’s extra messy because I have lead wires laying there for both sides. When it’s finally finished, I’ll be able to get rid of 1/2 of the cables and will make up a set of wires that I can hopefully tidy up somehow.
Now that solar is done, inverters are done, and I’m starting to see the finish line- it’s time to get the 2 banks of batteries wired together. The first thing to do is to top balance the cells so they are all as equal as possible.
When that’s done, I’ll wire every 2 cells in parallel (+ to + and - to -) and then I’ll wire up those 2 pairs in series to get up to 48v. This is called 2P16S.
(video is in the Imgur link above)
I truly still have a bunch of little nagging things left to do. Mostly wiring cleanup and interconnecting some bits. But I've got a great start at making power from the sun.