Adding a 2000W inverter to Tab320S

descott12 · May 2025

Hello all,
Just picked up my Tab last week!!!

I have been scouring this and other forums regarding how to properly ground my inverter and I am coming to conflicting conclusions about what should be a simple answer.

I am going to replace the single LiFePo battery with a pair of matched ones in parallel. No problem there. I want add a Renogy 2000 watt inverter but NOT integrate with the RV's AC system. I just want to hook it across the batteries and have access to AC for running a laptop or maybe to hook the microwave into. If I simply replace the existing battery with this new pair, they should charge normally via solar, the hitch connector and shore power.

The seems easy with the exception of the DC side ground on the inverter.
I believe I have found the AC chassis ground coming out of the fuse box. It is a bare copper wire going through the floor. I have not found a DC ground. In the battery compartment, there is a bus bar with two brass bolts labeled "To battery minus" and "To system minus". I believe this is tied to DC ground, but not sure.
So where should I run the ground wire?
Also the Renogy manual specifies 12AWG wire for the ground on a 2000 watt inverter and the terminal lug on the inverter is pretty small. This seems way to small since the battery cables are 1/0? Any thoughts?
Thanks alot in advance.
Dave

pthomas745 · May 2025

Tell us what year the trailer is....we do have threads on grounds, but there may be/will be differences with a brand new out of the factory trailer.

There is one excellent post about trailer grounds. This should narrow down what you are looking for. If you do have a brand new trailer, some photos of the bus bars and whatever else you are seeing would be a great addition to this thread.

https://tab-rv.vanillacommunity.com/discussion/14039/lets-get-grounded/p1

If you haven't seen these, many owners have added an inverter to a 320, and there is sure to be wiring advice in these threads.

https://www.google.com/search?q=add+320+inverter+site:tab-rv.vanillacommunity.com&client=firefox-b-1-d&uact=5&oq=add+320+inverter+site:tab-rv.vanillacommunity.com

descott12 · May 2025

Thanks for the reply. Yes I saw those threads. I think most people are trying to run the inverter into the tab's AC electric system. I don't want to do that so this should be alot simpler. It is a brand-new 2025. The first picture of the "Battery/system Minus" dual-bolt bus that I mentioned above. The second pic is the back of the fuse panel with the bare copper ground that I think is the AC chassis ground. The third pic is a battery NEG bus bar that a bunch of things are hooked into. It is in the same area as the fuse box. I believe that will connect with the brass bolts on the first pic.
I just noticed that the pictures were added in reverse...
Thanks again for your help

I

Image: https://us.v-cdn.net/5021717/uploads/editor/oq/i8a3qbdug3xk.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/7c/93cr5kceuycg.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/8u/27w7g5gsemgy.png

ckjs · May 2025

descott12 said:

… Also the Renogy manual specifies 12AWG wire for the ground on a 2000 watt inverter and the terminal lug on the inverter is pretty small. This seems way to small since the battery cables are 1/0? Any thoughts?

The output side ground doesn’t have to handle the ~180 amps that the inverter input needs. It’s standard for a 20 amp household circuit. The inverter’s GFCI will trip at 5 or 10 milliamps anyway — it should shut things off well before the ground wire carries that much.

donmontalvo · May 2025

pthomas745 said:

...[snip]...
https://tab-rv.vanillacommunity.com/discussion/14039/lets-get-grounded/p1

...[snip]...

Funny I posted to that thread earlier today. I attached an updated schematic.

I bought my 2024 320S with a single battery. My intent was to scale out power on my own, and intentionally kept the battery/solar separated from the WFCO side of things. The schematic (and a pic) show I had a 6 AWG stranded copper ground run through the floor and attached to the passenger side chassis. I made sure the connection was good, including ruling out any ground loops. It's been working great.

I now have two 100ah 12V LiFePO4 batteries in parallel, and a 1200W inverter. The inverter is not powerful enough to run the microwave, air conditioner, etc., but I understand that trying to run that stuff off battery is woolly thinking.

EasternJL · May 2025

We had the Lithium package (320) and could run the microwave and A/C off the batteries. Of course, you can't run them for extended periods of time, but it was nice to be able to cool the camper down when stopping for lunch-- or before bed when boondocking at a site that's right on the edge of a little too warm. You just have to budget your power. For instance, we knew that we were trading about 10% of our battery power for a pot of drip coffee in the morning! And with solar (and a generator at times), you could regain some of that during the day.

descott12 · May 2025

ckjs said:

The output side ground doesn’t have to handle the ~180 amps that the inverter input needs. It’s standard for a 20 amp household circuit. The inverter’s GFCI will trip at 5 or 10 milliamps anyway — it should shut things off well before the ground wire carries that much.

The funny thing is that little ground terminal is on the INPUT side of the inverter near the large DC cable connections so I assumed it input-related....

ckjs · May 2025

I can see why that placement would be misleading. I think my inverter also has the ground terminal there. I think that lets you hide the “installation” wiring inside a cabinet while still allowing you to cut a rectangular hole for the 120v socket, if you wanted to.

donmontalvo · May 2025

Does this help?

Image: https://us.v-cdn.net/5021717/uploads/editor/yv/nwc6r7aziusx.png

Doe

descott12 · May 2025

donmontalvo said:

Does this help?Doe

Yes, it does. Thanks alot. But I can't read all the text when the image is zoomed. What does the green ground line say? I see "6AWG stranded copper" and "Chassis ground" but can't tell what it says between them.
And my Renogy install manual for my inverter says to use 12 AWG wire for a 2000W inverter. That seems awful small...

donmontalvo · May 2025

(nm)

descott12 · May 2025

The attachment also got downsampled by this web app. Here is a link to the file on my blog page:

https://donmontalvo.com/wp-content/uploads/2025/05/20250511-camper-schematic.png

Thanks but that link says "File not found". No worries.

donmontalvo · May 2025

descott12 said:

donmontalvo said:

Does this help?Doe

Yes, it does. Thanks alot. But I can't read all the text when the image is zoomed. What does the green ground line say? I see "6AWG stranded copper" and "Chassis ground" but can't tell what it says between them.
And my Renogy install manual for my inverter says to use 12 AWG wire for a 2000W inverter. That seems awful small...

The Victron page on Facebook has 300K+ members, many of the folks that work at the company hang out there. I learned tons there, and as a plus got many OKs on my final setup.

https://www.facebook.com/groups/victronenergyusergroup/

donmontalvo · May 2025

(nm)

donmontalvo · June 2025

Apologies for the broken links, seems this forum downsampled my schematic image.

Here is a link to my blog page, if you scroll down to the schematic image (near the bottom) it'll open in high resolution in a new page.

https://donmontalvo.com/2025/05/02/

Adding a 2000W inverter to Tab320S

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