I have the latest 6500ex-48, delivered last week. My setup is ATS (fed by grid and generator), going to 6500EX, going to critical loads subpanel. This will mainly be used for grid backup. At the outset, I point out that the only place where the ground and neutral are tied together is the main panel. The sub-panel was also a manual transfer switch with two main breakers which are interlocked... one for the feed from the main panel, and one from the generator. I have now disconnected the generator, and will treat this "transfer switch" only as a subpanel with one main breaker. In its current config, the subpanel PE and N are separately bonded to the main panel, but not to each other. In my new setup, the generator and main panel (through a breaker) will connect to an ATS, with ground to ground and neutral to neutral, but the ground and neutral will again remain isolated from each other in the ATS. The generator is not grounded FWIW. The output of the ATS will feed the 6500EX, line to line, neutral to neutral and ground to ground. My confusion in regard to the code comes with the output of the 6500EX. If I follow your advice, I would connect the three connections on the output terminal block to the appropriate places in the subpanel, and let the 6500EX pass through the ground and neutral. But what do I do with the existing ground and neutral bonds between the subpanel and main panel? Can I leave them in place, or do I need to remove them? If I leave them, would this cause a "ground loop", or because they are all in close proximity, is it OK?
EG4 Official Neutral Ground Bond Thread.
- Thread starter James Showalter
- Start date
James Showalter
CEO, EG4 Electronics, Signature Solar founder
It is the same terminal now, input and output are shorted together 100% of the time
Physically connected together, or connected through a relay whose contacts are always closed, even when the unit is off?
James Showalter
CEO, EG4 Electronics, Signature Solar founder
via relay when unit has any power
ThePatriotDude
New Member
Correct, the electrical panel for the generator.
The generator has the neutral and ground bonded. The 50amp 4 prong cord splits the neutral and ground.
Considering that the 3KW units seem to also be shipping with the grounding screw removed, is there going to be a software update for them?
Failing that; given that the grounding screw is removed as shipped, any harm in just bonding N In and Out at the inverter?
Failing that; given that the grounding screw is removed as shipped, any harm in just bonding N In and Out at the inverter?
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
Connected together is fine.
"Bonding" implies grounding. That would be a no.
Cool, time to rewire some things for a better layout. I feel way better about relying on the house's N-G.
I can see how in this context using "bonding" could be confusing, however bonding is not strictly N-G bonding but any electrical bonding (such as bonding a metal conduit and/or box to ground). That being said, I can certainly try to use phrasing that has less potential for confusion!
Now, what would be the "right way" to do this? The input terminals could fit 2 wires side by side but that feels iffy (potential for one wire to be looser). Wire nuts maybe? The wagos I have are for up to 12awg/20A so that won't do. I assume the best solution is for the N-N connection to be as close to the inverter as possible so there's not a loop of N.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
That's what I said, "bonding implies grounding ".
The only thing that makes it N/G bonding is the fact that you are asking about bonding the neutral.
Wire nut near the neutral terminals.
I lowkey don't like wirenuts (since you often have to shorten the wire to make changes later) but I think you're right.
Now, do I have a wirenut big enough for 4 10AWG wires... (or do I do 2 joined together for 3 each which I DO have that size)
EastTexCowboy
Solar Wizard
You can get a Wago to do that if your largest wire is 10 awg.
So, I just brought up a similar setup. 2 Split phase EG-4 6500Ex-48 (2/2023 order date) and 6 EG-4 LL V2 batteries. I got it all "prototyped" on the wall and powered up. I have not changed the bonding on the inverter(s).
I confirmed that I have 120V/240V at my panel. Power output looks good. My panel is not bonded.
I'm getting indications of "Earth Fault" on a Charge Point EVSE charger and it doesn't matter if I grid tie the inverters or not, that fault is still indicated.
I assume that I need to move to the "mobile" firmware, bond the primary inverter with a bond screw?
I confirmed that I have 120V/240V at my panel. Power output looks good. My panel is not bonded.
I'm getting indications of "Earth Fault" on a Charge Point EVSE charger and it doesn't matter if I grid tie the inverters or not, that fault is still indicated.
I assume that I need to move to the "mobile" firmware, bond the primary inverter with a bond screw?
EastTexCowboy
Solar Wizard
H
How are you earth grounded?
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
It depends on how you have setup the rest of your system.
What do you need to know?
This setup is primarily used in USb mode, but not grid connected. Mobile use. It's typically charged over night from the grid with no load on it.
Output of the inverters is to a power panel that is setup like a typical sub panel, meaning no N/G bond on that panel.
The only time we are earth grounded is when grid tied. Interestingly enough when in pass-through mode we're not seeing the ground fault.
The typical use case when under load is no grid connection at all.
Adam De Lay
Solar Wizard
Your prob not seeing the fault because your getting a ground connection from the grid. Same thing happens to me when I hook up my portable power station to one of my UPSs for my computer. It throws a fit because it can’t detect a proper ground.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
If it's not connected to the grid. How is it charging from the grid?
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
This is on a vehicle?
Think of it as the "RV" use case. Sometimes there is a grid connection for charging, sometimes the vehicle is stand alone (with batteries).
Yea, probably. Course, whole house generators and RV generators are done w/o a grid connection or ground fault problems. So I'm asking about the specifics of this case. As I understand it currently, I need to install a N/G bond on the primary inverter and run "mobile" firmware, but I'm looking for some corroboration.
There are also these instructions which talk about bonding N/G at the panel when operating off grid.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
Then yes, you need to be setup as a mobile installation. Because you have no ground when not connected to grid.
Tim, what does that look like typically? In the RV case is the N/G bond typically at the generator / inverter? I'm familiar with residential, not mobile.
timselectric
If I can do it, you can do it.
- Joined
- Feb 5, 2022
- Messages
- 24,669
It's called dynamic bonding.
It happens inside the AIO, automatically.
When it switches to inverting from battery, it creates a N/G bond with an internal relay.
Got that. I think what I'm looking for, confirm if wrong:
The "source" is typically N/G bonded. Source might be:
- Main panel (if grid tied)
- Generator (if RV) or if in a scenario with a "whole house" generator
- AIO where it's in "mobile" mode
Some confusion for me where I see EG-4 cases where they are powering a panel and indicating to ground at the panel.
For Later EG-4 6500s (I think after 2/2023) there is no N/G bond screw installed. You need to install it and install mobile firmware.
Adam De Lay
Solar Wizard
I believe this is for a split phase setup where there's no AC In at all. The recommendation is to create the G/N bond in the sub-panel where you combine your AC Out from your two inverters (your first means of disconnect).
The screw was removed in units as far back as 10/22 from what I've seen. Regardless you would want to check and see if it's there (just to be sure).
Similar threads
