Planning a skoolie build using MPP LV6548V—wiring help

[Willardjwilliams]

Hi, hoping someone can give me a wiring diagram from shore power 50AMP RV INLET, to breaker box, to LV, to one 48v 280AH battery. I will have panels, most likely 8 @ 400-550w panels. In the future I plan on adding a second 48v battery in parallel. I’ve wired a 12v system before from Renogy using 2 parallel Rover100’s, 3000w inverter, and parallel battery bank, so I have a basic understanding. I’m new to this all-in-one kit and don’t want to get it wrong. For instance, I’m assuming I need two ACbreaker boxes? One for AC in and one for AC out? Can the LV6548v accommodate an AC IN of 50AMPS? greatly appreciate any and all help!

 

[Zwy]

No need for 2 breaker boxes. I did my truck camper with a GW 3000W LVM, you can read about it here. https://diysolarforum.com/threads/heres-my-truck-camper-setup.29488/

The current breaker box can be powered thru the LV6548 output if you tie both L1 and L2 together at the breaker panel or inverter output. The input of the LV6548 should be powered by the shore connection. The LV6548 has a built in transfer switch so on shore power it will switch the transfer switch to shore power, charge your battery and power loads.

The only problem will be the 50A shore power. A 50A RV shore power is 2 120V legs. I have a 30A RV plug and it works fine with a 120V inverter. With the 50A, you basically have 240V between legs so you can not run both legs into the inverter input. You could use a second inverter or the other choice is only use one leg of a 50A RV cord and tape the other leg off or disconnect. Personally, I'd just buy a 30A RV cord if you plan on only using 1 inverter. If you installed 2 inverters, then you can have L1 to one inverter and L2 to the other inverter and set the inverters up for 240V split phase while leaving the breaker panel wired as it currently is.

 

[Willardjwilliams]

Thank you. When I’m on shore power at camp grounds, I’ll need to run 2 one ton mini splits, plus other stuff. So maybe I need to go to split phase? Run two in parallel?

 

[Zwy]

As this is a skoolie and you probably have extra space, I'd definitely consider installing 2 inverters. This however increases idle consumption, not a huge problem in a stationary house with a large battery bank and large PV array. On an RV with limited roof real estate and a smaller battery bank, this might make things marginal if you ran into several cloudy days. One thing that can be done to reduce idle draw is to install remote switches if you don't need AC power 24/7. On my camper, I run a chest freezer/fridge which is DC powered and I don't have any other AC draws overnight so I can turn the inverter off.

If the units are inverter mini splits, then you probably could run just one inverter. The mini split in my living room never seems to draw over 1000W on initial cool down and it is a 1 ton 12K BTU unit. Running both at the same time with no other loads would be 2000W, well within the 6500W output rating.

If you haven't purchased any mini splits yet, then you have the choice between 240V units or 120V. The 240V units will always have a slightly higher SEER rating and you can run lighter wire. I prefer 240V units given a choice. On my truck camper, I am installing a 120V Senville 9K BTU unit because my system is setup for 30A.

If you already have the units, I'd install them, run some tests to see how many watts these take on shore power, then make a decision on whether you want to install 2 inverters or 1 nverter. 4000W of PV is about 1/2 of the size of my house array and I run a pair of LV6548's to power the house completely off grid with a 54Kwh battery bank. Spring, summer, fall I never run below 60% SOC so that should maybe help you decide if your system is large enough. The more battery you can install, the better you will be able to run anything you want and have power for a few days when PV yield is low without starting a generator.

2 inverters makes it easier to wire in for a 50A shore power connection. One inverter might limit you to 30A on shore power, that may or may not work out for you.

 

[Willardjwilliams]

That’s a lot to study and I thank you. Is there a single MPP all in one that does split phase or I guess just straight 240v? If I have one that is 240, I can just wire up for 50amp shore power and also service 120v needs? I guess I really want an all in one single box that will allow me to have 50 amp shore connection, but service my 120v needs. Any ideas? I get it I can do a parallel but I really want a single box.

 

[Zwy]

MPP LV6048
Victron MultiPlus- Available in several different outputs, you will need a SCC added to the system if you go this route

Is this occasional use or full time? What else will you run off AC power?

 

[Willardjwilliams]

MPP LV6048
Victron MultiPlus- Available in several different outputs, you will need a SCC added to the system if you go this route

Is this occasional use or full time? What else will you run off AC power?

So the MPP LV6048 allows me to feed it with a 50amp shore power? And I don’t need to parallel two? If it’s just one, do I get the 240v version? Is there then a separate panel connected to AC out that provides 120v. I really appreciate all the help.

Occasional. I’d like to take a trip per month for up to a week at a time. Sometimes camp grounds with 240v 50 amp connection. Sometimes not, so plan on building with solar and generator to charge batteries. Things we would be running:

120v
2*12k btu mini splits
Electric water heater
Good sized fridge/freezer (I’ll look for 24 or 48v system first)
Tv
Combo washer/dryer
Microwave
Coffee machine
Cooktop

12v
Lights
Pump
Automated leveling system (maybe)

I won’t be putting any propane on board. What is an SCC?

 

[Zwy]

SCC= Solar Charge Controller

So the MPP LV6048 allows me to feed it with a 50amp shore power? And I don’t need to parallel two? If it’s just one, do I get the 240v version? Is there then a separate panel connected to AC out that provides 120v. I really appreciate all the help.

As long as you purchase a unit with a built in transfer switch that will switch between shore power or inverter, then you only need one electrical panel.

Occasional. I’d like to take a trip per month for up to a week at a time.

That is often enough to be on par with full time needs.

Sometimes camp grounds with 240v 50 amp connection. Sometimes not, so plan on building with solar and generator to charge batteries. Things we would be running:

120v
2*12k btu mini splits
Electric water heater
Good sized fridge/freezer (I’ll look for 24 or 48v system first)
Tv
Combo washer/dryer
Microwave
Coffee machine
Cooktop

In your case, I'd opt for 2 LV6548's as that gives 13,000W of power or the Victron 8000W unit with a separate charge controller.

Those are some pretty good sized loads. Water heater, washer/dryer, microwave, cooktop and coffee machine. I doubt a 6000W unit will get you enough capacity when you need it.

12v
Lights
Pump
Automated leveling system (maybe)

I won’t be putting any propane on board. What is an SCC?

Only thing we use propane for is water heater, cooktop and furnace. Those are high btu items. We don't use the 3 way fridge, instead we have a Dometic CFX95 which is chest type (more efficient) and holds enough food for at least 3 weeks.