Common Neutral Split Phase and Neutral-Ground-Bond EG4 Six Inverter Installation

[timselectric]

As a contractor, I feel the same about all of my customers. I'm picky about the products and equipment I install for them.
I don't mind experimenting for my own personal projects. But customer warranty work costs me money, even if I'm not to blame for an issue.

 

[JCSchwarb]

As a contractor, I feel the same about all of my customers. I'm picky about the products and equipment I install for them.
I don't mind experimenting for my own personal projects. But customer warranty work costs me money, even if I'm not to blame for an issue.

Tim - that is very respectable and is why your reputation proceeds you. I run a fruit tree farm and nursery as my side fun job. I like to experiment with trees that will thrive in our local climate, so our farm is part educational too. So much of what gets sold in nurseries doesn’t do well for a number of reasons, but they don’t care as long as they make $$.

 

[PreppenWolf]

It's only an issue when in bypass mode. (Grid powering the loads, through the inverter)
And only if the inverter bonds N/G in bypass mode.

My units are currently in bypass supporting loads and charging my banks. Reminder I have NG bond screws still in both units. Load (offgrid) panel not bonded.



I just checked and currently with a 2kW load in house I am seeing 0.3A flowing on my ground wire from offgrid load panel. So there is some current.

When it finishes charging my bank I will turn off the AC inputs and recheck what my grid panel normally has flowing on ground for a comparison.

 

[JCSchwarb]

My units are currently in bypass supporting loads and charging my banks. Reminder I have NG bond screws still in both units. Load (offgrid) panel not bonded.

View attachment 126637

I just checked and currently with a 2kW load in house I am seeing 0.3A flowing on my ground wire from offgrid load panel. So there is some current.

When it finishes charging my bank I will turn off the AC inputs and recheck what my grid panel normally has flowing on ground for a comparison.

Thank you for the update and feedback. That is not good. I will do some testing on mine. I bought a whole house monitor as I can’t figure out my demands right now, loads are not adding up.

 

[timselectric]

My units are currently in bypass supporting loads and charging my banks. Reminder I have NG bond screws still in both units. Load (offgrid) panel not bonded.

View attachment 126637

I just checked and currently with a 2kW load in house I am seeing 0.3A flowing on my ground wire from offgrid load panel. So there is some current.

When it finishes charging my bank I will turn off the AC inputs and recheck what my grid panel normally has flowing on ground for a comparison.

Test the ground conductor on the AC input side of the inverters. While it's running now. This can help narrow down the issue location.

 

[PreppenWolf]

Only just over 1kw load right now.

It is 0.2A on the offgrid to grid ground line.

It is 0.2A on AC In ground to 2P1 & 0.1A on the AC In ground line to 2P2

2P1 AC out to Offgrid panel has 0.2A on the ground.

2P2 AC out to Offgrid panel has 0.1A on the ground.

 

[PreppenWolf]

My Main panel to grounding rod has 0.7A going to it at the moment. I know some if this existed before I installed the EG4s because I found it was happening when I ran a new subpanel to garage and dug it up.

I'm using a Fluke a3000 FC FYI. So I only have one decimal place.

 

[PreppenWolf]

I am working down here for at least another hour, maybe two. If you have things you want to check let me know. It should remain on bypass for a few hours charging batts.

 

[John Frum]

If I had .7 amps going to the dirt I would want to know why.
After the batteries charge, can you turn everything off and see how much current goes to the dirt?

 

[PreppenWolf]

Ok I forced back to battery and turned off the AC input breakers (Grid panel).

I now have 0.0 Amps on the offgrid to grid ground line. I still have 0.5A going to the ground rod.

Maybe it's going from my ground rod at garage subpanel, through the ground to main panel ground rod? The rods are 12ft apart (detached garage). The subpanel in garage is not bonded.

 

[John Frum]

Maybe it's going from my ground rod at garage subpanel, through the ground to main panel ground rod?

Could be.
It could also be coming from up or going down to a neighbor's ground rod.

 

[PreppenWolf]

Nevermind. That doesn't really make any sense because I moved the garage to the offgrid panel and the garage ground wire has 0A on it right now.

 

[PreppenWolf]

My neighbors are far way. The closest one is over 100 yards.

 

[PreppenWolf]

I suppose tomorrow I could go outside and measure for a voltage difference between the ground rods anyway.

 

[John Frum]

Can you turn off your service disconnect?

 

[PreppenWolf]

I can try that tomorrow when I warn everyone and the wife is awake. If I do it now the UPSs will all beep and she'll wake up.

 

[timselectric]

Only just over 1kw load right now.

It is 0.2A on the offgrid to grid ground line.

It is 0.2A on AC In ground to 2P1 & 0.1A on the AC In ground line to 2P2

2P1 AC out to Offgrid panel has 0.2A on the ground.

2P2 AC out to Offgrid panel has 0.1A on the ground.

If I'm following your terminology. The problem appears to be at or after your "off grid panel". Is this the sub panel in the garage?

My Main panel to grounding rod has 0.7A going to it at the moment. I know some if this existed before I installed the EG4s because I found it was happening when I ran a new subpanel to garage and dug it up.

I'm using a Fluke a3000 FC FYI. So I only have one decimal place.

This current is more than likely flowing from earth to the main service panel ground and through the N/G bond.

Ok I forced back to battery and turned off the AC input breakers (Grid panel).

I now have 0.0 Amps on the offgrid to grid ground line. I still have 0.5A going to the ground rod.

Maybe it's going from my ground rod at garage subpanel, through the ground to main panel ground rod? The rods are 12ft apart (detached garage). The subpanel in garage is not bonded.

In this mode, that would be return current flowing from the earth to the N/G bond in the inverters.
This confirms that the problem is at or after your "off grid panel". (I'm guessing after)
Turn off breakers (1 at a time) and monitor current coming from the ground rod.
Somewhere on one or more circuits, there is a connection between neutral and ground.

 

[PreppenWolf]

Ok, here's what I got.

First, with solar on, but its dark out, when you toggle the inverter from battery to AC bypass I get a momentary surge of 2A on the offgrid to grid panel and the ground rod. Then it settles to 0.2-0.3A (lack of resolution on my meter, it jumps between the two). Regardless of load. I tried pumping the load up with a big heat gun. No change.

Second, I've identified the circuit in my house responsible for the other 0.3A-0.5A. I haven't dug into the wiring yet, but I will.

 

[timselectric]

Regardless of load.

Even with no load?

 

[PreppenWolf]

Even with no load?

I haven't tested no load. I'll need to wait until everyone goes out for the day to click through breakers. I have all the critical stuff on the offgrid panel. I'll try to force it to AC charge when I do that to test it.

It's possible there's another dorked circuit with what I moved over to the offgrid panel. I hate gremlins....