Need Help With Solar Panels On RV

[SteelStudMan]

This is my first time setting up a solar system. Here's what I have:
1) 10 195 Watt 24 Volt Solar Panels Mounted On The Roof.
2) 100 AMP MPPT Controller
3) 8 100 AMP Hour 12 Volt AGM Gel Batteries
4) 3500 Watt Inverter, Can Handle 48 Volt.
Right now I have the panels wired in two sets of series (5 each) and the two series run together in parallel. I have the batteries wired in two sets of series run together in parallel, 48 volts. We're not off-grid, we have shore power and a generator but I would like to be able to rely on the solar if the power goes down or if we're camping off-grid. The thing I'm not sure about is the series/parallel thing, am I wiring them the best way for what I want to achieve? I would like to keep the amperage down so I don't have to use such large wires. Any suggestions?
Also, I have an automatic transfer switch for the shore power/generator, what's the best way to tie in the solar power? The transfer switch doesn't allow for adding another power supply. I'm new to this but have been doing all the work myself so I can learn the system. I've read a lot but it seems like every system is different for different requirements.
Any help would be greatly appreciated.
Thanks

[littleharbor]

For starters, what is the Vmp and Voc of the panels? What is the max Voc of the controller? Model numbers would help. Curious as to why such a large inverter? If to run an AC unit you are asking a lot from RV solar and batteries.

[chrisski]

This is my first time setting up a solar system. Here's what I have:
1) 10 195 Watt 24 Volt Solar Panels Mounted On The Roof.
2) 100 AMP MPPT Controller
3) 8 100 AMP Hour 12 Volt AGM Gel Batteries
4) 3500 Watt Inverter, Can Handle 48 Volt.
Right now I have the panels wired in two sets of series (5 each) and the two series run together in parallel. I have the batteries wired in two sets of series run together in parallel, 48 volts. We're not off-grid, we have shore power and a generator but I would like to be able to rely on the solar if the power goes down or if we're camping off-grid. The thing I'm not sure about is the series/parallel thing, am I wiring them the best way for what I want to achieve? I would like to keep the amperage down so I don't have to use such large wires. Any suggestions?
Also, I have an automatic transfer switch for the shore power/generator, what's the best way to tie in the solar power? The transfer switch doesn't allow for adding another power supply. I'm new to this but have been doing all the work myself so I can learn the system. I've read a lot but it seems like every system is different for different requirements.
Any help would be greatly appreciated.
Thanks

What is the max input voltage of your MPPT? That will determine if the wiring is good or not.

I can’t say anything for sure about the transfer switch. I plug my DC to AC inverter directly into shore power so I get AC at all the normal places. I do need to trip the circuit breaker for the AC to DC converter, otherwise my system expends 700 watts trying to charge itself. I’m not even sure if that is an option for your setup.

I am considering wiring a contractor relay to automatically shut off the converter when I turn my solar inverter on, and that could be adapted for the generator to solar charger, but I think bad things can happen if the generator kicks on or off when large loads like the AC are on. I’ve seen a blog where when this happens it blew a 200 amp battery fuse and over the summer, the couple went through a dozen 200 amp fuses. That just seems like a bad idea to put your RV in a situation where it blows through 200 amp fuses like that.

What is the intent of 48 V 200 AH battery bank? Is it to safely run a microwave, a toaster, or are you planning on running AC off this? When I go from 12v to 24v, I plan on going from 4 to 8 Golf cart sized batteries to run all the AC devices except the Air conditioning.

[SteelStudMan]

For starters, what is the Vmp and Voc of the panels? What is the max Voc of the controller? Model numbers would help. Curious as to why such a large inverter? If to run an AC unit you are asking a lot from RV solar and batteries.

I have attached the spec. sheet for the controller, it's an Epever 10420AN. If I'm reading it right it looks like the maximum Voc for the controller is 180/200 volts depending on temperature. As for the panels it shows a Vm rating of 18 volts, nothing about Vmp. The Voc is 21.6 volts. The inverter is just the one that came with everything. I'm not trying to run the AC, we have a mid-size refrigerator, TV's, lights and the 12 volt water pump I would like to run.

[littleharbor]

Sounds like you have 12 volt panels not 24 volt. That's very high wattage for 12 volt panels. Evergreen brand by chance?

Your inverter is likely incompatible for a small system being that the tare draw. (power used while just sitting there) is usually quite large.

To design a balanced system you need to start with load calculations and build from there.
Curious why you have such a big system in an RV. Did you buy it this way? Can you give us your model info for your panels and inverter

[SteelStudMan]

I ran five of the panels together in series and it gave me 120 volts which would make them 24 volt panels. I am attaching an image of the specs. for the panels. The inverter is an EcoWorthy:

https://www.eco-worthy.com/collections/solar-inverter/products/3500w-off-grid-pure-sine-wave-inverter-12v-24v-48v-to-110v?variant=30115926310964

Someone at work bought the system for me and I bought the MPPT controller and added four more batteries.

[littleharbor]

I ran five of the panels together in series and it gave me 120 volts which would make them 24 volt panels. I am attaching an image of the specs. for the panels. The inverter is an EcoWorthy:

https://www.eco-worthy.com/collectio...30115926310964

Someone at work bought the system for me and I bought the MPPT controller and added four more batteries.

Those are definitely 12 volt NOMINAL panels With a Vmp of 18 volts they are the same output as .virtually all 12 volt nominal panels. When you monitored the series voltage you were metering the no load, open circuit voltage and likely on a cool day to get a reading slightly higher than the data sheet shows. If you are truly using a 48 volt system then they are wired the only way that will work. Fortunately the high Voc. rating of your CC will allow a 5 in series configuration with these panels.

As to the inverter it is unclear as to the actual input voltage your inverter is. The use of the term "optional" makes me think that you have a choice when you order the inverter as to which input voltage it accepts.. Again, if you truly are going with a 48 volt system you still should justify the need for a 3500 watt inverter. Reason being that the larger the inverter the higher idle power draw they will have, usually. Many times this idle draw will be higher than your total power needs over the course of a 24 hour day and when you are depending on PV power to cover all your needs it ruins the delicate balance between power production and power usage.

[SteelStudMan]

Thanks for the input. You're right, when you do the math they're not 24 volt panels. Obviously, I'm not dealing with a high end system. It's still kind of weird that I got the 120 volts, it was a warm day, 80 degrees, nothing but sunshine when I got that reading. The inverter is most likely a 24 volt one, the manual is quite vague but makes it appear as though you can use 12, 24 or 48 volt input. When I hooked the 48 volt battery bank to it I got an error and beeping. I switched the batteries to 24 volt and it worked fine. Since I'm now running 12 volt panels with a 24 volt battery bank am I still okay with the panels wired as I have them? I've done everything except connect the controller to the batteries and the panels to the controller, don't want to mess it up until I'm sure everything is okay.