Hello everybody,
in the past few months I've been designing the off-grid system for my farm, with the help of an electrician. I already bought (almost) all the components and I'm installing it right now.
Now, I find myself stuck with the grounding of the system, because I'm not quite sure how I should wire the whole system so that it's as safe as it should be.
As a side note, consider the following:
- I know that it is advised to ask this kind of questions to a qualified electrician who knows the local regulations, but believe me, where I live (rural Panama) it's actually pretty hard to find one, let alone someone with experience with Victron products. In fact, I had to buy 80% of my components from the US because nobody sells them here. (for example it was literally impossible to find flexible wires, I had to buy them on Amazon. Same for 4/0 copper wire lugs and the tool to install them)
- regarding local regulations, forget about it, there are no specific regulations and nobody checks whether what I'm doing is good or not. The person in charge in this town does not know anything about off-grid systems, and is in fact waiting for me to complete my system so that he can see how it works
I had some help from en electrician online, and of course I studied all what I could find online, but there are some things that I'm not sure about, so maybe you can help me out.
Please find attached the diagram of the system (It's a work in progress).
Electrical Drawing with 1x BYD LVL.pdf
I believe that the grounding wiring needs to be fixed, because:
- 6 AWG for grounding the inverter is too small of a wire, because from reading Wiring Unlimited I think the wire should be tick enough to be able the carry the full current, which in my case is 250 amps, so the wire should be 4/0 AWG
- it's not clear what happens between chassis grounding and AC grounding. Is it a floating system? Do I need one RDC before the AC distribution? Does the PV part of the system have a dedicated ground rod for lightning protection?
This is where I'm stuck.
From my understanding, I think the grounding should be fixed as follows:
- the metal frames of the PV panels should be grounded with a ground rod
- the ground output of the PV combiner box should be connected to the same ground rod
- all the chassis of the components (the two inverters and the charge controller) should be connected in parallel with tick wire, and then connected to the central ground terminal of the Lynx Distributor
- from there, I should run a 4/0 AWG wire to a ground busbar (not shown in the diagram), where I should also connect the grounding wire for the AC distribution panel
- this ground busbar is connected to another dedicated ground rod
- there should be a RDC breaker between the inverters and the AC distribution panel.
Well, there's that, not sure what I'm missing, but I'm sure that something is missing in my understanding of the whole grounding deal.
I appreciate any help!
Edit: I added a screenshot of the diagram.