I'm running a completely independent system with no AC IN on the Growatt SPF 5000 ES to power a shed near my house. I have a 2 gauge cable running to a ground rod outside. This cable is connected to a ground bus bar inside a breaker panel. This is the only ground rod or ground connection on the system. (The house mains AC ground is on a different rod and the DC system is not connected to it in any way.) I'm creating a neutral using an autotransformer which connects to the neutral bus bar in the panel. Should I bond the neutral to ground in the panel? I'm vague on the answer to this so I don't want to proceed until certain.