question

allemay avatar image
allemay asked

How to Wire MultiPlus with Orion and aux alternator

Hi All,

I'm hoping one of you super smart people with free time will help me design this wiring. I'm converting a 2019 Sprinter Van into a camper. It is going to primarily be a road cruiser with occasional camping with hookups. There will be no solar and although I'll have 2 100 amp AGM batteries I don't plan to use them much. Here's the build...

I have an auxillary Nations 280 amp alternator. I have a 15k Dometic Penguin II air conditioner unit (110v) on the roof. I have Victron MultiPlus 3000 inverter and Orion DC to DC 30 amp battery charger. I will have a 30 amp shore power connection. The alternator was designed specifically for the AGM batteries. My intent is to have the house system entirely separate from the chassis systems. I have one giant 0000 gauge cable coming from the alternator. Now what? I'd be willing to pay someone a fee to help layout the plan for this. I don't quite understand how to allow charging of the batteries from the alternator and from the shore power. I need to have the full alternator capacity available to the inverter to run the inverter since the AC will use a lot of power.

Thanks in advance to anyone that can assist.

Brad from MN

allemay@yahoo.com

Multiplus-IIorion-tr smart
1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

allemay avatar image allemay commented ·
Anyone?
0 Likes 0 ·
2 Answers
liam-tuvey avatar image
liam-tuvey answered ·

If I understand what you are trying to do correctly. The wiring should be very simple. The Multiplus, Orion and house battery should all connect via common positive and negative busbars. If you have an isolated Orion then you can treat this whole system as separate to the chassis system.

It would look something like the following.

  • Shore power -> Multiplus AC in - > DC bus bars
  • Alternator -> Orion charger -> DC bus bars
  • House bats - > DC bus bars
  • DC loads -> DC Bus Bars

I really like the Victron Lynx distributor for this kind of solution. Its got really beefy busbars and it's easy to add fuses for each input / output.

When on shore power you should have AC pass-though to power the air conditioner, as well as charge the batteries. When off shore hook up the bats can be charged by alternator.

However the system you've described wont be able to run the air from the from the inverter, That air conditioner unit is rated at 1700w. So 1700w divided by 12v = around 140amps! So ignoring any inverter losses thats still way too much power to pull from 2x100ah AGMs. And there is obviously no way the Orion can put that out as it only rated at 30amp

Assuming you only want to run the air conditioning while on shore power. I'd use the AC2 output from the Multiplus to run the air conditioning. This output only works when connected to shore power and wont try to power the AC via the inverter. Any devices connected to AC1 will use the inverter function (if enabled) when off grid.

-----

If you wanted to power the air from the alternator via the multiplus inverter you'd need multiple Orions connected in parallel or some other solution.

This is outside of my knowledge, but in theory (sticking with Victron kit here) it would be possible to connect 5x 30amp Orions to the 280A alternator giving you 150amps,@12v DC the AGM bats would provide some sort of buffer to smooth out the load / supply. And you could then run the air from the alternator... I'd note that this would depend on the Orions all being working at max output if they got hot (and they do get hot!) then they will drop their output.

I have no idea if this is a workable solution, it certainly makes me nervous! For one you'd need to ensure that the alternator is running before the air is turned on else you'd attempt to pull that 140a from the bats.

I hope this helps.

Maybe someone with more experience could chime in!

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

allemay avatar image allemay commented ·
Thanks for the detailed and thoughtful response. I hope you're wrong about powering the AC from the inverter. I plan to run the full amperage of the alternator directly to the inverter (via a busbar) therefore not being limited by the Orion limitation. Then the inverter should have the necessary power to run the AC. Then also off this busbar I'd go to the Orion and then to the batteries. This of course if what I'm struggling with so maybe I'm wrong. I think I need to spend some quality time with the user manuals. Thanks again for the response. If what I said sounds wrong to you please feel free to school me!
0 Likes 0 ·
Charlie Johnson avatar image
Charlie Johnson answered ·

liam-tuvey gave some really good advice. For more in depth advice I recommend Nate of Explorist Life. He is a Victron Ambassador and has produced an exceptional series of DIY videos on upgrading vans with Victron equipment. https://www.explorist.life/

1 comment
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

allemay avatar image allemay commented ·
I took a look at that site quickly on my phone. I'm going to reach out to him and see if he can provide a schematic or guidance. Thanks so much for that resource!
0 Likes 0 ·