Solar wiring


Forgive me, I hope I’m not asking a question with an obvious answer. I searched and could only find answers about everything but this: I’m using a Renogy PWM 30 amp controller; two panels, one mounted on the racks and one portable totaling 220 watts. I have a #6 Hotwire from the house battery to a fuse box, where power is distributed to the small Engle freezer and an ARB 63 fridge. A small subwoofer and an 800 watt power inverter are also fed from this box. My entire solar system is negative ground wired in parallel. I’ve already found out that with my vehicle it is quite acceptable to run negative to ground, ( ie- the vehicle) everything is wired that way. However, every PMW instruction book says don’t tie in to the power inverter line. I’m no electrical engineer but if two hot wires are fastened to the same battery post is that not doing the same thing? If the battery is taken away it is nothing more than a "Y" connection at the battery. Why can't that "Y" connection be anywhere along the line? It is a closed system, unless there is a switch to isolate the power inverter it’s all one current anyway. That would mean no power inverter usage when the sun is up. I just don’t see the sense in running another big line through the firewall and out to the battery again.. help me out here solar experts, and thanks
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I think I understand the issue. It isn't the positive side is a Y-connection. It is the ground side. Sounds like you just ground to the body anywhere it works. Power flows in a loop, battery post to battery post. Ground is just a reference point. Pull a strong load and there can be voltage drop across the ground. Now you have the evil of automotive electrical that makes all kinds of strange issues that a lot of well educated people can never figure out, bad grounds. Not complete failures, those are fairly easy to track down, but the weak ground under load.

For the high current stuff run feeds directly to the battery, not just to ground. Let any high load devices deal with there own voltage drop in there own wiring and not connected to the whole vehicle.