I'm setting up an off-grid solar system to power some chest freezers in my basement using a previous shed setup as a reference. I've realized I might have made a mistake with my Automatic Transfer Switch (ATS). I connected the grounds from both the grid and the inverter together, thinking it wouldn't cause any issues. Now I'm worried that this could lead to back-feeding the grid during a ground fault, which defeats the purpose of having an ATS that isolates the two systems.
I'm planning to disconnect those grounds, but I'm unsure about where to ground my solar system. Ideally, should I use a copper grounding rod? If so, won't this rod be electrically common with my grid's ground rod? In that scenario, if there's a fault in my solar system, wouldn't it also energize the grid lines? I really want to make sure I keep things safe and properly grounded, given the grid is still active even though it's not in the same circuit. Is grounding even a big concern for such a basic setup?
1 Answer
Your grounding setup sounds fine! The initial connection between grid and inverter doesn’t really harm anything. Just ensure your systems are bonded properly. In an off-grid context, it's essential to maintain the same ground reference. So tying them together can actually help keep your setup safe. Don't worry too much about back-feeding through the ground as long as everything is fused properly.