multiplus II. 50A fifth wheel

[Sportzfann]

I am looking for a wiring diagram to connect my solar, batteries, and a multiplus II in my fifthwheel.
I have a 50A panel and want to use all the outlets and appliances. If I need ac I will have a generator with me.
I know I can’t exceed the rated load of the inverter, but want to be able to not run my generator All the time.
I plan to have about 1000w of solar on the roof. 400ah of lithium Thanks, Sportzfann

 

[MisterSandals]

Maybe something here?

Search results for query: Multiplus diagram

diysolarforum.com

 

[BobH]

See this post. It's a diagram from Victron... https://diysolarforum.com/threads/5...-up-on-a-45-foot-toy-hauler.58819/post-736384

 

[chrisski]

In my fifth wheel, I have my 3000 watt inverter hardwired to a 30 amp plug which I plug into the side of the RV Through a 50 amp adapter. Just like when going to an RV park with only 30 amp service.

When I want to run the gernerator, I disconnect the inverter and plug in the generator. For me, I have never needed to use the generator, but have tested it a few times. THe generator powers a 37.5 amp AC to DC converter to charge the batteries.

As an alternate, you can install a transfer switch, either manual or automatic.

 

[MisterSandals]

I have my 3000 watt inverter hardwired to a 30 amp plug which I plug into the side of the RV Through a 50 amp adapter.

How do you keep from trying to charge the batteries from the "shore power" in this case?

 

[chrisski]

How do you keep from trying to charge the batteries from the "shore power" in this case?

I need to physically switch off the DC to DC converter when not hooked to the grid/shore power.

Forgetting to shut off a 37.5 amp 24 volt converter can be extremely wasteful.

When I am charging with the generator, the fan in the converter is noisy enough to be heard, so if I did forget to trip the breaker, the fan would let me know.

There is a build on YouTube that uses a contractor relay to keep from accidentally doing this.

 

[RoadTurtle]

I have 1200w/600ah, and mostly pleased. My personal experience, 400ah can be a bit light. I find 600ah gives me enough head room for multiple days in a row with little to no solar collection. I'm seriously considering increasing my solar to 1600. As a test I let my propane fridge run on electric and kept the water heater on electric for 24 hours, which hit the battery much harder than I expected. Got down to 17% at the end of the experiment, and 6 days later, still not achieve 100% SOC. I leave 120v and 12v running 24/7. We watch TV in the evening, use kuerig every morning, use microwave as needed, even use crock pot. Basically live as normal, but treat off grid like we have a 30a power source. I've had to teach my wife she can't use her hair dryer while another large load is running. I can also run my airconditioner after I added Microair easy start. Can only run it for about 5 hours, but that has really helped in pre trip work without shore power.
.
Few suggestions

Go with the physically largest battery that will fit in your chosen location​

Seriously consider 24v. I didn't and regret it​

Put the solar panels on a rail system of some sort. I mounted directly to the roof, and may be changing. Avoid potential shadows, as that was my nemesis.​

Don't stop at 1,000w, fill the roof now. Panels are pretty cheap. I set mine up with drivers side SCC and pass side SCC. Because I'm already at 13'5", I couldn't go over the other junk on the roof... but also consider maintenance on roof equipment.​