Can the Victron SmartSolar MPPT RS 450/100 support a -48V DC battery bank (positive ground)? I looked over the manual and did a search, but haven’t found a definitive answer and the example in the manual didn’t show any grounding on the battery/DC side. All it mentions is the PV is isolated from the DC and not to ground the PV strings, but nothing about if you can ground the positive “+” terminal on the DC side.
pretty niche thing to do, i must say. I do know of some types of systems that do this.
No explicit prohibition in the victron literature, but non-standard and unverified definitely.
Negative is the usual side to ground.
Yet electrically it appears possible because the MPPT RS is galvanically isolated between the battery and PV.
However, as you noted, the PV array must remain isolated from ground, and the rest of the Victron system must also be compatible with a positive-ground DC system. The MPPT itself is not likely to be the limiting factor—the rest of the system needs to be considered.
Why are you considering it?
Thanks for the insight. The equipment is telco so it needs -48v unfortunately so that is the driving factor. I’ll check continuity from ground to the negative. Maybe I will check with a small wire from the + to ground first if there is no continuity from the negative to ground to see if anything happens.
I checked the battery terminal’s + and - on the RS 450 to the chassis ground and didn’t find any short. I did connect the + terminal to ground to get -48V and it didn’t have any issues. Perhaps the add on modules may have issues, but I’ll have to check on that if we get them.