I’m upgrading my Van with Victron products. I have 4/0 wire connecting my batteries via the Lynx Distributor in my van to the Multiplus II 3000 120. The Multiplus has the battery negative (ground) and also requires an additional case ground (M6 bolt “primary ground connection”, connect F). I’m unsure where that ground should be secured and what Gauge to use.
To size the gauge of the Primary Ground, do I base it off the 4/0 12V wiring or the 6G 120V wiring? I’m thinking of just using 4/0 because I’m not sure and want to be safe. As I understand it, the case ground engages when not connected to shore power for the 120V inverter. I use 6AWG for 120V and had planned on using that for the ground. But it sounds like I need to base it off the largest ground wire, which would be the 4/0. Perhaps as protection in case the 12V line grounds and needs an alternate return path?
And, do they have to go to different ground sources, or can they be connected to the same grounding busbar? I’ve seen several methods and instructions online that seem to conflict depending on who is explaining it. DC negative goes to the Lynx Distributor, which then is ground to the van chassis. Can the multiplus II case ground also go to the Lynx distributor negative? Or can it go to the same place on the chassis the Lynx is grounded? or should it have its own bolt to the chassis?
I thought a ground was a ground. But I know there must be a reason they have that ground separate from the 12V (instead of just internally connecting them together to save extra wiring). But in demos I see, people connect them both to the same busbar, which seems like it’s kind of the same thing as just connecting them in the multiplus…which obviously they did not do when designing it.
If anyone can help me understand, I’d really appreciate it! Thanks!
