Powering All AC Circuits w Inverter

Tybooo

New Member
Joined
May 6, 2023
Messages
3
Hey there! First post here. Hopefully I'm doing this right. If not, please be gentle. I just picked up our new 2022 GD reflection 28BH with inverter prep and solar. This is my first GD so I've been living on these forums for the past week. HUGE help, thank you. We really only dry camp so ive been beefing up the off grid power. I understand the inverter prep wiring and how it powers a few circuits in the coach. I need to be able to power the whole rig on the Victron MultiPlus II 12/3000/120-50 2-120v. I can think of a dozen ways to do it but I thought surely there is a standard that I have yet to discover. Just looking for the path of least resistance.

Other upgrades in this project:
- 800 Watts of solar
- 810 ah BB LiFePO4
- lynx distributor
- A/C Soft starts

I need to be able to run a 13,500 btu A/C for about an hour per day during nap time when we're in the national parks that don't allow generator use.

Thanks for your help! -Tyler
 
Hey there! First post here. Hopefully I'm doing this right. If not, please be gentle. I just picked up our new 2022 GD reflection 28BH with inverter prep and solar. This is my first GD so I've been living on these forums for the past week. HUGE help, thank you. We really only dry camp so ive been beefing up the off grid power. I understand the inverter prep wiring and how it powers a few circuits in the coach. I need to be able to power the whole rig on the Victron MultiPlus II 12/3000/120-50 2-120v. I can think of a dozen ways to do it but I thought surely there is a standard that I have yet to discover. Just looking for the path of least resistance.

Other upgrades in this project:
- 800 Watts of solar
- 810 ah BB LiFePO4
- lynx distributor
- A/C Soft starts

I need to be able to run a 13,500 btu A/C for about an hour per day during nap time when we're in the national parks that don't allow generator use.

Thanks for your help! -Tyler

The MultiPlus II with 2 x 120v output is a fantastic piece of equipment.

The easy answer to your question is: remove the two 120v input wires (along with the Ground and Neutral) from the breaker box and wire them to the input side of the MultiPlus II. Take the two wires from the output side of the MultiPlus II (along with the Ground and Neutral) and wire them into the spots you previously disconnected the wires from. Connect your batteries and you have 120 volts throughout the coach.

Additionally, you will want to remove the old Inverter and make certain all those circuits are properly re-wired.

Two things I would like to mention: First, if you are going to run your Air Conditioners, I would highly recommend you install a 24 volt battery bank (along with a 24v MultiPlus II). You will get much better conversion from 24v to 120v than you will with a 12v battery bank. Additionally, you can run smaller gauge wires with a 24v system.

Second, With 800 Watts of Solar, I feel that you will not have enough Solar to keep your batteries fully charged, especially on overcast days, or days when you need to run the Air Conditioner. I would seriously consider doubling your Solar Wattage. I don't know which panels you plan on purchasing, but if you decided to buy 350 - 400 Watt Residential panels, you could achieve the necessary Solar Wattage with only 4 Solar panels.

Check out this thread on Solar Installation:

Affordable-Solar-How-To-Design-and-Install-an-Affordable-Solar-System

Be sure to link to the various other threads included in the above thread, there is a wealth of knowledge in all those threads.
 
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Hey there! First post here. Hopefully I'm doing this right. If not, please be gentle. I just picked up our new 2022 GD reflection 28BH with inverter prep and solar. This is my first GD so I've been living on these forums for the past week. HUGE help, thank you. We really only dry camp so ive been beefing up the off grid power. I understand the inverter prep wiring and how it powers a few circuits in the coach. I need to be able to power the whole rig on the Victron MultiPlus II 12/3000/120-50 2-120v. I can think of a dozen ways to do it but I thought surely there is a standard that I have yet to discover. Just looking for the path of least resistance.

Other upgrades in this project:
- 800 Watts of solar
- 810 ah BB LiFePO4
- lynx distributor
- A/C Soft starts

I need to be able to run a 13,500 btu A/C for about an hour per day during nap time when we're in the national parks that don't allow generator use.

Thanks for your help! -Tyler

Here is a good video for you. https://www.youtube.com/watch?v=TjYSG_EDJWc
 
The MultiPlus II with 2 x 120v output is a fantastic piece of equipment.

The easy answer to your question is: remove the two 120v input wires (along with the Ground and Neutral) from the breaker box and wire them to the input side of the MultiPlus II. Take the two wires from the output side of the MultiPlus II (along with the Ground and Neutral) and wire them into the spots you previously disconnected the wires from. Connect your batteries and you have 120 volts throughout the coach.

Additionally, you will want to remove the old Inverter and make certain all those circuits are properly re-wired.

Two things I would like to mention: First, if you are going to run your Air Conditioners, I would highly recommend you install a 24 volt battery bank (along with a 24v MultiPlus II). You will get much better conversion from 24v to 120v than you will with a 12v battery bank. Additionally, you can run smaller gauge wires with a 24v system.

Second, With 800 Watts of Solar, I feel that you will not have enough Solar to keep your batteries fully charged, especially on overcast days, or days when you need to run the Air Conditioner. I would seriously consider doubling your Solar Wattage. I don't know which panels you plan on purchasing, but if you decided to buy 350 - 400 Watt Residential panels, you could achieve the necessary Solar Wattage with only 4 Solar panels.

Check out this thread on Solar Installation:

Affordable-Solar-How-To-Design-and-Install-an-Affordable-Solar-System

Be sure to link to the various other threads included in the above thread, there is a wealth of knowledge in all those threads.

Great insights, you're definitely right on the solar being insufficient. My hope was that it would just slow down the imminent battery death. Started working on how to get it up to 1,100 watts for now. My coach came with one 370 watt panel already, makes it hard to add based on where it was placed at the factory and just even finding more single residential panels without spending a grand in shipping. I already have the 12v batteries :(. Good to know for next time.
 
Great insights, you're definitely right on the solar being insufficient. My hope was that it would just slow down the imminent battery death. Started working on how to get it up to 1,100 watts for now. My coach came with one 370 watt panel already, makes it hard to add based on where it was placed at the factory and just even finding more single residential panels without spending a grand in shipping. I already have the 12v batteries :(. Good to know for next time.

You can still install a 24 volt system by simply connecting two batteries in series and then the four battery pairs in parallel using the "Buss Bar" method.

As far as upgrading your Solar, you might consider leaving the OEM Solar system alone and just add your new panels along with their own Solar Charge Controller. This can greatly simplify the install process.

Your comment about "Working on how to get it up to 1,100 watts for now", makes me think that eventually you would want more Solar Wattage. In the thread linked above, there is a link to a thread titled: "Installing a Solar System in Phases". In this thread I mention how it is better to plan for the system you eventually want, instead of the system that will get you by today. The reason is to avoid buying the wrong components today and needing to remove and replace them with the components you really want at the end. A good example would be buying a 1,000 Watt Inverter today and installing cables that are sized for the 1000 Watt Inverter, but, you eventually plan on installing a 3,000 Watt Inverter. You would need to replace all the cabling because it is too small to power the 3,000 Watt Inverter. If you know the design of your final system, you can still install the 1,000 Watt Inverter, just install cables large enough to power your 3,000 Watt Inverter. This way you are not wasting your time and money on components that will need to eventually be torn out and replaced.
 
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You can still install a 24 volt system by simply connecting two batteries in series and then the four battery pairs in parallel using the "Buss Bar" method.

As far as upgrading your Solar, you might consider leaving the OEM Solar system alone and just add your new panels along with their own Solar Charge Controller. This can greatly simplify the install process.

I have 3 of the GC3 batteries, 270 ah ea.,still possible to go 24v with that?

I think I have a solution for the solar, ive been on the phone all day with BB and Victron making sure my harebrained works, as most folks say to not wire up mismatched panels. Ideally I don't have to buy a second controller and fish more wire up through the roof. I realize that I have the vmpp and impp number switched in the schematic. A silly typing error. Anyways this should get me 1100 watts without needing a thicker gauge than stock down to the solar controller and I only lose 40 watts in the mismatch.

Screenshot 2023-05-09 at 3.11.28 PM.png

Screenshot 2023-05-09 at 2.57.13 PM.png
 
I have 3 of the GC3 batteries, 270 ah ea.,still possible to go 24v with that?

I think I have a solution for the solar, ive been on the phone all day with BB and Victron making sure my harebrained works, as most folks say to not wire up mismatched panels. Ideally I don't have to buy a second controller and fish more wire up through the roof. I realize that I have the vmpp and impp number switched in the schematic. A silly typing error. Anyways this should get me 1100 watts without needing a thicker gauge than stock down to the solar controller and I only lose 40 watts in the mismatch.

View attachment 46248

View attachment 46249

Unfortunately, with the 3 batteries, you have, you can't get to a 24v battery bank.
 

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