Outback E-panel Inverter Ground wire

[joeedens]

I ordered 2 each E-Panel PLUS Alum 175A for Outback, to use with the VFX 3648 Inverter.  The E-Panels came with the 2/0 AWG Inverter cables but didn't include a ground wire for the inverter.  Why not include the ground wire?  What size ground wire do I need for the VFX 3648?

[Halfcrazy]

We use the Chassis of the Epanel as ground. As long as you use the included star washers on the inverter and the door the Outback will have a solid mechanical ground.

[joeedens]

Halfcrazy, thanks for the quick reply. I'm pretty good with the theory of electronics, but when it comes to code issues and practical implementations of grounding systems, I get confused.  So are you saying that I don't need a green ground wire running from the chassis ground lug located just below the battery cable connections on the outback 3648, to the chassis ground bus on the E-panel?  I'm really confused now, because page 8 of the E-Panel instructions included with the E-Panel says "The picture to the left shows the ground wires coming in from the inverter and charge controller mounted on the door. Do not rely on the hinges for grounding the equipment mounted to the door. The Neutral to ground bond wire has not yet been installed in this picture."  What am I missing?

[Halfcrazy]

I just chatted with Robin directly about this. The washers do provide adequate grounding but only when the door is closed. We do add a ground wire when we pre wire them so I would say add the ground wire. I apologize for leading you astray 

[joeedens]

Halfcrazy, thanks again and this just confirms for me that the grounding issues are complex and even the experts see the implementation from different angles.  So what size wire should I use to ground the inverter?

[joeedens]

Halfcrazy, while looking through the Classic users manual while I'm installing 2 classic 200's I've come up with another thing that is confusing me.  On page 19 is says:

"DC System Grounding
The Classic charge controller is designed to work with negatively grounded or ungrounded power systems. In grounded systems, dc negative may be connected to ground either externally or by using the Classic's internal grounding jumper, shown on figure 2.1. The internal grounding jumper should only be installed when the Classic's GFP is enabled. In a system with multiple charge controllers the grounding jumper should only be installed on one charge controller. If the charge controllers have different voltage ratings, install the jumper on the charge controller with the highest voltage rating.
DC GFP (Ground Fault Protection)
The Classic has internal ground fault protection (GFP) built in. Since 2008 the NEC requires a DC-GFP on all PV systems in the USA. The built in DC-GFP eliminates the need to purchase and install an external DC-GFP. If the internal grounding jumper is installed in a Classic, the battery negative and DC source negative must not be connected to the system grounding conductor anywhere in the system. Grounding of these circuits will defeat the GFP function. In a network with multiple Classics, all Classics must have the internal grounding jumper installed and enabled. The factory setting......"

The 2 statements in red have me confused.  In my system I've got 2 classic 200s.  Each classic is connected to a separate solar array of 2 strings of 6 230V evergreen modules.  In the combiner box the 2 arrays are separated and each one has its own separate classic 200 but the classics connect to a common 48v battery bank.  In this configuration should the GFP jumper be in place on both classics or only one?    Also with this separated array configuration with both classics connected to a common 48v battery bank is one classic considered the master and networked to the other as a slave, or are they not networked at all??   Thanks for all of your help.

[Halfcrazy]

Well that is another confusing spot. Currently the Classic's do not network so each Classic needs its own GFP enabled. Soon boB will have networking done and than just one will need GFP as it will shut down all the Classics on the network. At least that is my understanding as of today although I can think of reasons not to shut them all down so I will have to talk to boB some more on this one.