SolarFlex 2 panel limitation - Montana Owners Club

Superchief05 · 08-20-2023, 04:05 PM

I own a 2021 MHC 372RD. It is prepped for the SolarFlex 200, which can be expanded to 400W (or 600W) of solar, depending on the panels. In the literature it states that the SolarFlex only supports a maximum of 2 panels per roof port. Does anyone know the limiting factor of the solar panel wiring? is it the port? I just saw a video by explorist life where they installed 4 panels in series on a competitors solar prep system with a single port. In this case the solar connecting wire was 10 AWG, similar to the Solarflex. I would like to install 4 panels, but not pull additional wire. TIA.

Foldbak · 08-20-2023, 04:21 PM

Quote:

Originally Posted by Superchief05

I own a 2021 MHC 372RD. It is prepped for the SolarFlex 200, which can be expanded to 400W (or 600W) of solar, depending on the panels. In the literature it states that the SolarFlex only supports a maximum of 2 panels per roof port. Does anyone know the limiting factor of the solar panel wiring? is it the port? I just saw a video by explorist life where they installed 4 panels in series on a competitors solar prep system with a single port. In this case the solar connecting wire was 10 AWG, similar to the Solarflex. I would like to install 4 panels, but not pull additional wire. TIA.

You're prepped for 1 more panel. The 200 has 1 panel and if you look you'll find a connector that will accommodate another panel. Giving you 400 watts.
You have a 15 amp Victron solar controller so you'll need to upgrade to a 30amp. If you're really handy you can add as many panels that will fit on the roof but you you'll have a lot of wiring and necessary components to add. There are several solar pros here that have installed 1200 watt systems themselves. My 400 is prepped for 2 more panels.

Check this thread

https://www.montanaowners.com/forums....php?p=1243234

https://www.youtube.com/watch?v=Zu-3sz2afoU

Superchief05 · 08-21-2023, 01:41 PM

Thanks for the reply. I have nothing installed yet, just the prep. I am trying to add more than the 400w of solar without additional wires.

Daryles · 08-21-2023, 03:57 PM

Our 2019 3130re. Came with "Solar Prep" wiring which is 10 gauge. 10 gauge is good up to 30A.
So, configure your panels series/parallel (SP) so you don't exceed 30A output from the panels to the MPPT controller.
Next, do not exceed the input voltage of the MPPT controller.
Next don't let the MPPT output exceed 30A (10 gauge wire to the battery).
For example, I have 800W of panels wired 2S2P.
2S gives me 42vdc. 2P gives me 18A DC going into a 100/30 Victron MPPT. 100/30 means 100vdc maximum input and 30A maximum output.
Yes I have way over paneled but it works great on cloudy days or in partial shade. Full sun I need to turn OFF the circuit breaker coming from the solar panels when the batteries are full (early morning).
I'm going to upgrade the MPPT to a 150/70 to be able to add more panels and upgrade the MPPT to batteries wire to 4 gauge.
If you are just in the planning stages, install unistrut rails on the roof then mount the panels to the rails using Renogy tilt mount brackets.
Using unistrut rails allows you to mount the rails and hit the roof rafters with every mounting screw (use a stud finder). Having tilting panels allows you to inspect and clean under them.
Also having rails allows you to replace or reconfigure the panels without drilling new holes. When you install rails put a couple of washers between the screws and the roof to allow rain to run off. Use LOTS of Dicor on everything.

Superchief05 · 08-21-2023, 04:32 PM

Thanks for a very thorough answer. I appreciate the time you took. I thought I could attach several solar panels as long as I did not exceed the 30A limit. Are you using an inverter? if so which type. Thanks again and good luck with your upgrade.

Daryles · 08-22-2023, 06:38 AM

The first inverter I bought was a Go Wise P1003 2000W (4000w surge). Its standby draw was very little. It worked fine. It would not run the new microwave when we replaced the HighPointe when it died. MANY inverters put out the following voltage:
Hot to ground = 60vac
Neutral to ground = 60vac
Hot to Neutral =120vac.
This one died (4 years old) while we were in Canada this summer. Bought a new one at Canadian Tire (which is actually like a Super Walmart). The new one is a
Motomaster Eliminator 3000W (6000W surge) PSW.
The output voltage is the same as what you see on a household wall receptacle. So far I'm very pleased with it. It runs the microwave and the bedroom AC unit (SoftstartRV installed) no problem. Individually of course.
Next project will be wiring in an Automatic transfer switch.

rames14 · 08-22-2023, 08:39 AM

Super chief, good explanations so far. There are a number of things to consider as you expand your system. We are going through expanding our 1200i system. Wiring size, solar charge controller size and your batteries. Are you using lithium batteries and how many amp hours. What do you plan on running with your system while off grid? You will find it cheaper in the long run if you start out identifying your end goal. For example, don’t buy a 2000 watt inverter if you are eventually wanting to have all of your outlets inverted. The same for choosing the brands for your equipment. Last year we expanded our system with the Victron Cerbo GX for remote monitoring. That allowed us to add Mopeka Pro propane sensors and monitor wherever we have WiFi. SeeLevel now makes a monitor that works with Cerbo as well. Don’t limit yourself by equipment choices up front. Best of luck.

Superchief05 · 08-22-2023, 02:57 PM

Thank you both. I think the most difficult decision is the inverter. I could go with a 2KW Inverter and run the 7 outlets, and that is fine for an overnight enroute, but does what can be run. And if I wanted to run an A/C, I would have to purchase a second 2KW to run that (on a limited basis). I am wondering if I could purchase a Victron Multiplus 2 and put the A/C on one leg and the Solar "loop" on the other, until I am ready to increase the size of the system. BTW, at present I have 200 Amp Hours of Lion Energy Batteries. Not enough to run a lot at the moment, but it is almost sale season.

jetskier · 08-22-2023, 04:26 PM

Quote:

Originally Posted by Superchief05

Thank you both. I think the most difficult decision is the inverter. I could go with a 2KW Inverter and run the 7 outlets, and that is fine for an overnight enroute, but does what can be run. And if I wanted to run an A/C, I would have to purchase a second 2KW to run that (on a limited basis). I am wondering if I could purchase a Victron Multiplus 2 and put the A/C on one leg and the Solar "loop" on the other, until I am ready to increase the size of the system. BTW, at present I have 200 Amp Hours of Lion Energy Batteries. Not enough to run a lot at the moment, but it is almost sale season.

I have the 3000w Multiplus with 600Ah of batteries feeding it. I rewired the entire electrical panel with a separate subpanel for the inverted items (everything is on the inverter except water heater, 3rd AC, converter (abandoned), washer/dryer circuits). It required another transfer switch on top of the one that the generator (5.5kw Onan) uses. I have the two ducted ACs wired in so I can pick one to run at a time on the inverter when I don't want to run the generator. An AC unit draws approximately 150Ah of battery storage per hour of use. I have 1200W of solar and on a good day, it puts out 700-850W in the peak hours. It's not enough to power an AC exclusively, but just extend the runtime a bit. Both those ACs also have easy start modules.

rames14 · 08-22-2023, 08:52 PM

Your new Multiplus is a hybrid and will also take over charging your batteries on shore power. Your Solar Charge Controllers will also connect to the battery. Think about all of the things you will run (coffee, microwave, TV’s, StarLink, satellite dish/receiver, furnace, etc.). With soft start, 540 ah of lithium batteries and 1200 watts of solar plus DC-DC charging, I can run AC a few hours. Your first purchase should be a smart shunt so you know your usage/charge levels.

Daryles · 08-23-2023, 06:56 AM

My plan, when I install the ATS, is to power the entire circuit breaker panel with the 3000w inverter when dry camping.
Right now while dry camping, I manually switch from generator to solar/battery/inverter power.
I turn off all circuit breakers except for the circuits I am using. This prevents overloading the inverter or the generator. It helps to properly label every circuit breaker versus the generic labeling that's there now.

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