EG4-6500EX with Grid Backup

[Henderson]

Hi all, I'm wondering of all the folks with the EG4-6500EX who have these connected to the grid as backup, how is this configuration working for you since the various firmware upgrades for these models have been released? I have 2 of these inverters and have a choice of setting these up as fully off-grid (off-grid with no grid backup) or off-grid with grid-backup, so would appreciate persons feedback.

I do have a manual transfer switch where I can completely bypass the solar setup and feed the house with power from the grid if I need to, but would be ideal to run the grid into the inverters so the inverters can automatically switch to bypass mode if the need arises. Will still use the manual transfer switch in case I need to take the entire solar system offline for maintenance.

Thanks in advance.

 

[Adam De Lay]

I've been running my house in battery mode as long as I have capacity, but when my SOC drops down to 30%, I switch over to grid and let grid supply the power till my batteries can recharge to 60% then everything switches back to battery.

I will say that a lot of my documented issues (issues/annoyances/bugs) have revolved around grid-bypass mode, but none of them have prevented the inverters from running in grid-bypass. Issues like when running in grid-bypass (SUB) the inverter doesn't supply all incoming solar to the loads before pulling from the grid (known issue that SS is aware of).

I live in MI and we're still in that phase where the weather doesn't know what season it's supposed to be (it's always in that phase in MI ? ) so there will be days when the sun doesn't shine. I don't have enough battery capacity to last till the sun starts shining again, so I fall back to grid power.

 

[Henderson]

Where you mention about being in grid bypass and the inverters not using all the PV to supply to the loads....isn't that how it's support to work? I thought as these are off grid inverters, they will either pull all power from PV, or all power from PV and battery or all power from grid. What you are referencing I thought only hybrid inverters provide that functionality.

 

[Adam De Lay]

Where you mention about being in grid bypass and the inverters not using all the PV to supply to the loads....isn't that how it's support to work? I thought as these are off grid inverters, they will either pull all power from PV, or all power from PV and battery or all power from grid. What you are referencing I thought only hybrid inverters provide that functionality.

So if you look at the manual (https://eg4electronics.com/wp-content/uploads/2023/03/EG4_6.5_Manual_2.3.1.pdf) on page 40, you'll see option 1 (output source priority) and it defines what each priority is supposed to do.

SUB -"Solar energy provides power to the loads as first priority. If solar energy is not sufficient to power all connected loads, Utility energy will supply power to the loads at the same time."

It's the same thing in SBU mode when your inverter switches to Utility due to option 12 being triggered.

So when in SUB mode, solar should provide power to the loads and only draw from utility if there's insufficient solar power available. This doesn't seem to be the case. I have seen this happen many times where I'm pulling in a few kw of PV on each inverter and I'm still drawing from utility. There seems to be some threshold, but I can't figure out what it is. Sometimes if the load is really small, it will get covered by PV. Sometimes if the load is close to the same amount of PV coming in, it will be fully covered.

I told SS about this last Nov/Dec and they're supposed to be working on a firmware fix.

 

[Henderson]

So if you look at the manual (https://eg4electronics.com/wp-content/uploads/2023/03/EG4_6.5_Manual_2.3.1.pdf) on page 40, you'll see option 1 (output source priority) and it defines what each priority is supposed to do.

SUB -"Solar energy provides power to the loads as first priority. If solar energy is not sufficient to power all connected loads, Utility energy will supply power to the loads at the same time."

It's the same thing in SBU mode when your inverter switches to Utility due to option 12 being triggered.

So when in SUB mode, solar should provide power to the loads and only draw from utility if there's insufficient solar power available. This doesn't seem to be the case. I have seen this happen many times where I'm pulling in a few kw of PV on each inverter and I'm still drawing from utility. There seems to be some threshold, but I can't figure out what it is. Sometimes if the load is really small, it will get covered by PV. Sometimes if the load is close to the same amount of PV coming in, it will be fully covered.

I told SS about this last Nov/Dec and they're supposed to be working on a firmware fix.

Ok thanks, I think I was getting the modes mixed up.

 

[Adam De Lay]

Ok thanks, I think I was getting the modes mixed up.

No worries.