Isolating grounds in Solar installation

[ddinnsen]

I have 400 Amp service split into two 200 Amp panels. I’m converting one to a protected loads panel as part of a PV solar system with battery backup. Since ground is tied to neutral I want to isolate the neutral and ground buses of one panel from the other to make sure no current flows to the other panel during an outage when only the protected loads panel has juice. I have 7 circuits in my protected loads panel that are tied back somewhere to the ground in the other panel. I’m thinking of slipping an insulator, such as a piece of polyethylene tubing, over each ground to insulate them from the box, and then connected them to an insulated ground wire running to the other box. I would be connecting two #12 and four #14 to a single insulated #8 ground wire that runs to the other box. This would solve my problem, but I've never seen it done. Is it OK to use polyethylene on a ground wire?

 

[Megawatt]

I have 400 Amp service split into two 200 Amp panels. I’m converting one to a protected loads panel as part of a PV solar system with battery backup. Since ground is tied to neutral I want to isolate the neutral and ground buses of one panel from the other to make sure no current flows to the other panel during an outage when only the protected loads panel has juice. I have 7 circuits in my protected loads panel that are tied back somewhere to the ground in the other panel. I’m thinking of slipping an insulator, such as a piece of polyethylene tubing, over each ground to insulate them from the box, and then connected them to an insulated ground wire running to the other box. I would be connecting two #12 and four #14 to a single insulated #8 ground wire that runs to the other box. This would solve my problem, but I've never seen it done. Is it OK to use polyethylene on a ground wire?

DD there is nothing wrong with putting tubing over the naked grounds but the first panel after the meter has to be bonded to ground rods and you can wire the ground and the neutrals to the same bar. Any subfed panels you have to isolate the grounds from the neutrals

 

[davesparks]

Since ground is tied to neutral I want to isolate the neutral and ground buses of one panel from the other to make sure no current flows to the other panel during an outage when only the protected loads panel has juice.

I don't really follow what you mean here. How will current flow from one panel to the other via the ground and neutral?
The ground throughout the entire installation should be connected together. And whatever you do the neutral will ultimately all connect together at the intake.

 

[Lucien Nunes]

Doesn't make sense to me either. There should be no need to disconnect or segregate any grounds. As I understand it, you are saying that some circuits in panel A have their grounds in contact with that of panel B at a remote point. You want to isolate the grounds of those circuits from panel A, and get their ground from panel B so that there's no connection between the panels, although they would still be powered from panel A.

Why can't you connect both panel grounds solidly together? That doesn't in any way constitute 'energising' one panel from the other. Anything that is grounded must be safe to contact anything else that is grounded.