Trailer System with Modular Ground Array (Grounding Confusion)

[xprimnt]

Hi everyone,

I’m finally ready to ask my scary grounding question(s). I’m confused on the most effective and safe way to do this. The overarching theme is that we have some land with nothing on it, and we want to power 2-3 RVs while we explore and clear the area for a more permanent spot for the RVs and potentially move again in the future. This lets us have a semi-mobile power station in an off-grid fashion and I’m very excited for it (We would be moving it maybe once a year as we clear further in)!

The setup description is basically an enclosed trailer with the solar system in it with a few panels on top/side. My understanding is that this is a floating ground situation, and my plan is fusing both sides on the battery/roof PV strings. There seems to be nonconsensus on whether to connect inverter ground to chassis, so I’m not sure about that but it seems at least somewhat safe either way. The tricky part for me comes in when we “park”. We will be setting up a semipermanent ground PV array near the location (That could be taken apart and moved to the next location, but is not located on the trailer). This will then be plugged in to the solar trailer to add PV capacity and beef up our input.

Here’s a basic picture. The full diagram is more complicated, but this should highlight the questions I have.


I would appreciate any input on the setup and how you would ground or fuse the system. I have specific questions too!

1) Should I just ground the solar PV array on the ground?

2) Should I ground solar equipment to chassis, then consider attaching to a ground rod to the chassis when we are parked semi-permanently?

3) Should I do something completely different, like grounding the DC negative to chassis and the solar equipment grounds, and leave the PV ground array ungrounded? Or ground to chassis only and ground the PV array? My understanding is that generally you only want one actual ground rod, but it confuses me that the solar array on the ground is more modular. Or maybe my fusing/breakers on the floating system is dumb, and I need to change that.

I really appreciate the insight and further questions! Happy to elaborate the setup if you need more information to weigh in.

 

[45North]

I don't know anything about the grounding.

But you should take a look at Will's YouTube videos on his solar trailer builds:

• there's a flatbed trailer that is wall-to-wall panels that flip up when you get on site
• there's a walk-in, lockable, trailer that contains the related equipment like batteries, controller, etc ...

 

[xprimnt]

I don't know anything about the grounding.

But you should take a look at Will's YouTube videos on his solar trailer builds:

• there's a flatbed trailer that is wall-to-wall panels that flip up when you get on site
• there's a walk-in, lockable, trailer that contains the related equipment like batteries, controller, etc ...

Thanks! @Will Prowse ‘s trailer(s) was one of the catalysts for this whole thing, as I was trying to figure out something that would fit our needs.
Unfortunately, I don’t really see much at all for grounding/fusing in his videos regarding the trailers, hence my cry out for help!

Also, I think because both of his array and equipment are on a trailer, maybe it is different than my planned ground panel array? But maybe not, I don’t know!

 

[xprimnt]

I think it is safe to say I’ve become more confused as I read more about options.

Bumping for smart people to weigh in! Thanks again. Trying to make sure I have all my wiring figured out before placing a hopefully final online order.

 

[SalckwareRobert]

Rubber tires on trailer, wooden frame for panels and they are insulated, but if you grab one while on the ground yourself you could make a circuit if there was a problem, and you just had the trailer frame as ground.
Long term setup, I would put the ground rods in. Maybe think about a hydrolic jack, or winch system to pull them out, they are going way up in price now. Or leave them in and use to hook up long wires, and try to gather energy from the earths magnetic field. LOL

The main thing is only having one point where your neutral bonds to ground. Put a GFI outlet on your trailer for a quick dirty check of ground problem.

here is some good reading... https://diysolarforum.com/resources/categories/how-to-pdfs-or-ebooks.4/

 

[xprimnt]

Thanks!

I think I’ve decided to just ground it. Ground plates and ground rods don’t seem particularly concerning when I only plan to move it very rarely.

 

[12VoltInstalls]

You should have the battery negative grounded to the trailer. All other negative cables should be connected at the battery or a buss bar that connects to the battery negative.
The safety grounds of inverter and any other accessories that have a second/chassis ground should be tied to the battery negative as well. Those are a safety layer.

120V green/safety ground should be grounded.
There are two recent, active threads that discuss 120V ‘grounds’ and contain excellent information and links from the ABYC codes that you should look up and review to handle that 120V stuff properly and safely.