question

cory cantrell avatar image
cory cantrell asked

New Dual Multiplus Inverters RV Setup - 50AMP

Hello Smart folks,

Hoping I can get some thoughts/assistance if anyone wouldn't mind verifying what I am thinking isn't nutty...? I am only showing the AC side diagram I created as that is where most of my questions come into play.

Currently I have a stock RV 2021 Forest River GT7 36K7. I have purchased a dozen solar panels a Victron 150/100 charge controller and a single 3000 Multiplus. I want to be able to run everything (should I chose to go this route) as I would today off of the battery power even if it is just for a short time. I have 6 105ah Lion Energy ut1300's which I know wouldn't run all of this for very long, but want the flexibility to be able to if I wanted for even an hour.... My question is based on the below drawing, will this accomplish the goal of that?

What I want to be able to do:

1.) On 50 amp shore power run everything as I can today.

2.) On 30 amp or less shore power run everything from the AC panels with the shore power and the power assist kicking in for the additional required power.

3.) If I so choose try to run anything (or everything) off of battery only power (even if it is only for a short period).

4.) The Victron Cerbo Touch Screen Energy Control GX System w/Color Display that I ordered to be able to monitor my single 150/100-tr Victron charge controller, and my two multiplus inverters, along with my lynx distributer (future I heard it can send info back to the gx, but not current).

In the setup below if the above 4 are covered, is that considered parallel or split phase? I am not an electrician (obviously lol) but I am reading and trying to comprehend as much as possible, I get hung up on things I don't fully understand in some of the other threads on similar topics such as setting these up in parallel vs split phase ect. Since I don't fully understand the terminology and what each fully mean, I have a hard time telling if the below is true split phase or actually what this would be considered?


In the thread here there are 3 options presented. Which I admit I don't fully understand and maybe I should present my questions on that thread for that side, but didn't want to hijack his thread and it is a year or so old, so not sure how much it is being followed. Does the below diagram fall into this category [3}?

[3] You can run them in a split-phase pair. There are two advantages of this approach compared to stacking. First, your two units are wired to each phase when on a 240V supply, so you have access to the full 12kW at the pole, subject to the internal limits of your MultiPluses. (They won't be able to charge that much, for example.) Second, if you have a single phase supply (120V 30A, 20A, 15A), you can feed it to one side and the other side will reject incoming and stay in inverter mode. You will have seamless load support on both legs, but you will be going through the battery for the second leg. A consequence of this setup is that if you have a large 120V generator, you may not be able to fully utilize it, because it can only feed one of your two units.

Finally, the above bold/underlined statement makes me feel I would not be setting this up with option 3 via the below diagram? Mainly because I see my diagram below representing these operating as individual units each controlling a phase (or leg) of the load and then the phases remaining separated as individual legs, and I assume the AC panel in my drawing keeps each phase individual (ie one 50 amp leg operates 1 side of the panel, the other operates the other side of the panel).

Please be kind, I am not masquerading as if I know this stuff I am only trying to learn and apply what I have learned to my situation. I am a DIYer and don't want to higher someone because I find this stuff really fun, but I also don't want to do something terribly wrong... The hand drawn diagram (that says CURRENT in left column) is how the current RV is wired from the factory (other than the batteries which I replaced the stock ones day one).

Please let me know if there is a better way to accomplish this, I also have drawn up a diagram to try to do this same thing with a "Smart Phase Selector" and a single inverter (since I only have an order in for 1 right now). But then the wife sprung on me "I want to be able to run other things besides what is on the small subpanel from battery if your going to be spending this type of money". So I will ultimately either do what I have suggested below (if you guys agree it will work and fulfill the needs.

My options as I see them now:

1.) The diagram in color (pending your review as to if that will work, and covers my needs) Most expensive as it requires me to buy another inverter. Or any recommendations you guys give me to adjust this setup.

2.) The hand diagram below that says "Smart Phase Selector" in left column which is the second most expensive, and you can't find the "Smart Phase Selector" anywhere in stock. More info on this item: https://amsolar.com/rv-inverter-accessories/50-tsfmb1

3.) The third and least expensive option is to use one of these https://www.amazon.com/Baomain-Universal-Changeover-SZW26-63-Position/dp/B01IZ5ZFYC/ref=sr_1_1?dchild=1&keywords=B01IZ5ZFYC&qid=1614029317&sr=8-1. This is the drawing that is had drawn with Future #2 on the left side. The Pin out wiring is on the same drawing with the circle numbers for the switch representing each position and how I think I would have to wire it to make it work. Position 1 of the switch for 50 amp Shore Power. Position 2 for all other single phase connection or Inverter for entire RV. I would use position 2 when connected To 15 amp 20 amp or 30 amp.


Do I gain much on via option 1 to option 3 for the price difference? ect.


Thank you all in advance, and if you made it this far, I hope to hear back :)

manual-phase-selector-1-inverter.jpg

sps-diagram-1-inverter.jpg

current-ac-rv-electrical-setup.jpgac-future-dual-inverter.jpeg

MultiPlus Quattro Inverter Chargermultiple inverters
2 comments
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Matthias Lange - DE avatar image Matthias Lange - DE ♦ commented ·

Uff... wall of text. I din't read it completely.

This community is not the right place to discuss system designs.
You should contact your local Victron dealer/installer for that.

https://www.victronenergy.com/where-to-buy

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trigmish avatar image trigmish commented ·
Did you get your answer? This is my exact situation and i suspect a very common RV’er one. I am surprised at how hard it is to get an answer, even from the installers.
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2 Answers
bostonfamily1181 avatar image
bostonfamily1181 answered ·

Cory this all looks like the right way to power up a 50AMP RV using two Multiplus charger/inverter. Did you get confirmation that this works?, I know this is an older post, so I am sure you have this all working as expected by now.

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derrick thomas avatar image
derrick thomas answered ·

In my opinion the easiest way to do this in a 50a RV is with a mp2 2x120, provided there are no 240 loads, which there usually is not. The mp2 2x120 can be stacked in parallel for higher output. The 2x120 automatically does what it needs to do wether plugged into 50a split phase or 30/20a single phase. Many RV generators have 2 legs of output but are not split phase, if that is your situation you will need to consider that.

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trigmish avatar image trigmish commented ·
What is the down side of this? Y plan was to run in parallel to get 6kw of inverter but still have the full 12kw power source coming from shore power if plugged in. The installer installed the system with on inverter on each leg and I cried foul. Do you have a schematic? I don’t have an onboard generator but use two inverter generators running in parallel plugged in to that shore power outlet.
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derrick thomas avatar image derrick thomas trigmish commented ·
The manual for the mp2 2x120 shows the wiring schematic for both parallel and series configurations. When plugged into split phase 50 amp you still have the full 12k available to the rig. If you don't have any 240 loads in the rig then parallel configuration really would be a better way to go for north American RV's. If you don't have the 2x120 models then it really is a mute point this late in the game.
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