Open Ground Fault on EG4 3K EHV-48

[Beeralph]

Hi, I am new to solar system DIY and am trying to install an EG4 3000 EHV-48 inverter to 2 EG4 Lifepower4 Rack mounted 48V 100 Ah batteries. I have them connected to 4 solar panels in series producing 120-160vdc. The system works to power a heat gun with the AC 120v power, but when I check the outlet with a plug in fault detector it gives an open ground fault. The fault goes away if I plug 120vAC from the house to the inverter. I intend to use this to recharge my 2020 Ford Fusion plug in Hybrid. It takes 9kw to get to work and back and I have 10kw of batteries. When I plug the charger cord in I get a fault light. I have contacted signature solar and they are supposed to be having a level 2 tech contact me, but it has been over a week and no joy. I have attached a hand drawn wiring diagram. There will be more circuits eventually, but I want to get the desired result before I expand the system. Any help will be appreciated.

 

[Dave in AZ]

Sounds correct to me... without being plugged into 120 wall power, your ground is not bonded probably. There should just be 1 ground neutral bond in a total system, so there isn't one set in your eg4 as it assumes wall power provides that probably.

In mobile systems, you actually need to switch the ground neutral bond on and off when you upplug shore power or plug it in.

Go look at Wills recent video of the eg4 3000, he actually did an update because of this bonding issue and peole found errors with his setup due to the way he had it bonded, since the device doesnt automatically switch this.

 

[Beeralph]

Thanks for the info. I'm assuming Willis is a member of this forum?

 

[42OhmsPA]

Thanks for the info. I'm assuming Willis is a member of this forum?

The man, the myth, the legend and the forum owner; @Will Prowse

 

[Beeralph]

I can't find the video you mentioned. Could you post a link?

 

[Beeralph]

Here is an update on the open ground issue. I found a thread on workarounds with EG4 3k programming on this site. I would like to thank that guy, but I can't find the thread again. His advice to enable setting # 28 to SIG worked. I was locked out of the single inverter setting for some reason. On his advice, I plugged in ac house power, then I was able to select SIG. This got rid of the open ground fault with my tester on my AC outlet. My car charger was still giving a fault light though. I reset setting # 1 from SOL to SUb. This setting allows solar as first priority and utility as secondary. That enabled me to plug in my car charger without a fault light when house power was plugged in. My car is fully charged right now, but tomorrow I plan to see if I can charge it from the batteries this way. My fear is that it will just charge straight from the utility instead of using battery power. I tried setting it at SbU but my car charger gave me the fault light. If it just charges straight from the grid when there is no solar, my plan will have been defeated.

 

[Dave in AZ]

Well, if it doesn't work you can always add a switch to connect and disconnect a ground to neutral bond wire. Just to solve your ground fault issue. For battery, disconnect wall power, throw switch to bond ground to neutral, should be good. Reverse to use wall power.

This is something that RV amd campers have to deal with every single time they plug into an RV shore power socket or unplug. Well, if they know what they are doing and doi g it correctly...

 

[Beeralph]

Thanks Dave. Not sure if that will work. One of the first things I tried was to jumper a ground to AC neutral. That didn't solve the open ground, but that was before I changed the SIG setting.

 

[Beeralph]

I have been in email correspondence with signature solar for quite a while now. So far I am the one coming up with solutions. I have inverter to the place where it will charge partially with solar and the rest with utilities. I still can't set the inverter to sbu (solar, battery,utility) without getting a fault code on my car charger. This means I can't use the batteries to charge my car.
When I test with my plug in tester it says open hot. Even the though it says that, everything but my car charger works just fine. Even my mini split works in heat mode. That is impressive because it always trips breakers on the 20 amp plugs at campgrounds. It works at home just fine, but I have to use a 30 amp adapter cord at most campgrounds.
In order to see how the neutral in relay latched( hot or neutral trigger) I disconnected the hot input to the inverter with the neutral still connected. The AC out showed a fault on my car charger. This tells me that the AC hot wire input is the one that latches the relay to connect neutral. I informed my tech support about that last Friday. I have not heard anything from them since then. I don't think there's a way to get my batteries to charge my car with this inverter. Today I emailed tech support and asked them to solve this or refund my purchase so that I can try something else. I have not heard back.