One thing that applies to everything I say about grounding and safety. I am not an expert (not even solidly intermediate), I have a limited understanding of electrical theory and grounding theory, I am certainly still learning and probably misunderstand a thing or two. Bearing that in mind, here are my thoughts:
Oops sorry, I missed that, was looking out for green wire or a ground symbol.
At the very least the Inverter should be grounded in accordance with the manufacturer recommendations which probably means bonding the inverter case to the negative busbar.
My understanding of the semi-default (there is no default you need to make sure whatever you do works for your situation) grounding logic is that all EGC's (equipment ground conductors--the wires between the metal non current carrying parts of your components and your system ground point) go to one central point which is than bonded to DC negative and(or) Chassis ground (see attached image).
There is slightly more complexity with an inverter charger, because it needs to internally switch the ground depending on whether shorepower is connected or not. And of course I have only touched on the DC side of things, I won't comment on the AC side because I am not knowledgeable enough and it scares me ?
It is my understanding that it is recommended (however your PV panels may be grounded by default if you use metal fasteners to connect the metal frames to a metal roof (or metal ribs).
If both sides of your system are grounded then your DC-DC charger will not be isolated regardless of whether you buy the isolated or non-isolated version because the negative sides of both systems are bonded together via chassis-ground. Regarding grounding, if memory serves, Victron does not stipulate grounding for the DC-DC charger.
SCC can also optionally be grounded (in the same way as you ground the inverter/charger to the negative bus).
In my opinion this is one of the hardest aspects of a mobile built (with multiple charge sources) to wrap your head around. I am still struggling to really understand it and feel confident in my understanding. But slowly, I'm starting to get there.
I would say a good way to start learning is to really pour over some of the schematics put out by reputable companies (such as the Victron one I posted earlier). And check out some of the Inverter/Charger manuals they have sections on grounding as it pertains to mobile/marine systems.
Samlex and
Magnum would be two I recommend peaking at. Also check out the free Victron E-Book
Wiring Unlimited and the
ABYC guidelines (this is Marine code, but super useful for vehicle based builds too)