Hey everyone! I'm in the process of building a stand-alone solar system and I could use some guidance. Here's what I have: 3 solar panels rated at 12V/400W, an 80A charge controller, a 4000W inverter, and a 12V320Ah LifePo battery. My main questions are regarding safety and setup—specifically, how many DC or AC circuit breakers do I need, and what thickness of wires should I be using considering the currents involved? Thanks in advance for your insights!
2 Answers
It's great that you're diving into solar! However, I would recommend being really careful. Understanding the current flow and creating a diagram would be a solid start before anyone gives you more specific advice. Safety is paramount when dealing with electricity, especially with solar setups.
If you sketch out a basic setup, that could help those who want to assist you to see you have a grasp on it!
Hey! I recently set up a 9kWp off-grid system myself, and there’s a lot to consider! Start by calculating the worst-case scenarios for current in each part of your system. You need to select wires based on these calculations. Don't forget to add circuit breakers that will trip before exceeding wire limits.
A "combiner box" between the panels and the MPPT can also help with electrical safety and allow for more strings if you decide to expand later. And make sure to have a disconnect switch for the battery, plus a distribution box with breakers on the AC side. Good luck!
I really appreciate your detailed response! I'm still learning, so I've made a rough sketch of my setup. Could you take a look and let me know if you have any suggestions? I picked the inverter first, which is why I’m tied to a 12V system. I have a 4mm² cable for the panels, but I’m clueless about the larger cables and DC breakers. Thanks for your help!