EG4-18k Grid-tied with 7.6kw Ac-coupled

[djl400]

Replacing two grid tied LVX6048 with a EG4-18Kpv. Going to keep the 4 SOK server rack batteries, 5kw of solar mounted to the top of the shipping container. 10kw ground mount SMA AC coupled system will be connected to the EG4-18k Generator input. Is powering a 100% electric house, and one EV.

Old System

Still a work in Progress, rushed to get online before the hurricane. Waiting on some line side taps so I can clean up the wiring and put the covers on.


Install and setup went smooth, AC coupling was very easy and worked right away after I enabled it. I installed it on a Saturday but had to wait tell signature solar was open on a Monday to call and get the customer code "Signature" so I could register it and setup the app for remote access, they should include the code in the order confirmation E-Mail so you don't have to call them.

The only problem I am having right now is I am running the batteries without comms because the manual doesn't really give any information on what comms settings to use with different brand batteries. Signature solar recommended I E-mail EG4 and ask them about it. I called current connected and they are looking into how to get the comms to work with there batteries.(current connected called me back and said I just need to change the setting on my master battery to "pylon can" , I changed the setting on master battery and the comms are working now.)

I still need to. Feed inverter with line side tap before main breaker box in shipping container than feed container and house breaker box off of inverter load output so it will all be backed up. Going to use a back feed breaker with interlock to feed main panel from inverter so I can bypass inverter if needed.

Once wiring and comms are done I will simulate a grid outage to check the transfer time, see how it does with the 2hp Well, 1hp booster pumps, 2hp air compressor and two air heat pumps. Really interested to see how the AC coupling works when grid is down. I can already tell I need more batteries to be able to run air conditioners off grid over night, will also need more solar during the winter to run the heat pumps. I will post more updates after I do more testing. (Did a quick test of a grid failure and it switched over without interruption everything stayed on and lights didn't flicker. SMA Ac coupled inverter kept working tell I turned the grid breaker back on then the SMA inverter stopped feeding for the 300 second timeout then kicked back on )

 

[Vince Mex]

Hi

Thanks for sharing your experience. I am making plan for a similar system and would like to exchange informations with you. I have a 9,75 kwh grid tie system with a Fronius 11.4 kwh inverter that i plan to connect AC couple (connect the 9.75 kwh to the generator input of the eg4 inverter) to a new 20.9 kwh system with a EG4 18kv and 3 powerpro batteries. I have doubt about the frequency shifting the AG4 is supposed to do when off grid and batteries are full, about the ups function as well and also the charging capacity of "only 250 amp" so 12 kwh that in my case is not enough i think with a 30 kwh array.... i thought to add a charge pro 5 kva directly fed by 9.75 kwh inverter in the hope to have 12 + 5 kwh of charging power but i do not know if and how i can do that.... Did you checked all theses points ?

 

[djl400]

Hi

Thanks for sharing your experience. I am making plan for a similar system and would like to exchange informations with you. I have a 9,75 kwh grid tie system with a Fronius 11.4 kwh inverter that i plan to connect AC couple (connect the 9.75 kwh to the generator input of the eg4 inverter) to a new 20.9 kwh system with a EG4 18kv and 3 powerpro batteries. I have doubt about the frequency shifting the AG4 is supposed to do when off grid and batteries are full, about the ups function as well and also the charging capacity of "only 250 amp" so 12 kwh that in my case is not enough i think with a 30 kwh array.... i thought to add a charge pro 5 kva directly fed by 9.75 kwh inverter in the hope to have 12 + 5 kwh of charging power but i do not know if and how i can do that.... Did you checked all theses points ?

Sorry for the late repIy, I have been having problems with the inverter since august but EG4 has not updated the software to fixed the issues yet and I have not gotten any reply's from them since November. I am going to try getting in touch with there customer service again. Inverter Hardware is nice but the software is not finished and has a lot of bugs with AC coupling. I will reply if the issues get resolved.

The 12wh of charging should be enough for you system. I would try the 12wk for a winter and summer and see if you really need more charging power. You will probably not want to let the batteries get bellow 20% just in case the grid goes down so at 12kw you will have 100% batteries in 3 hours.

 

[Scotts954]

Sorry for the late repIy, I have been having problems with the inverter since august but EG4 has not updated the software to fixed the issues yet and I have not gotten any reply's from them since November. I am going to try getting in touch with there customer service again. Inverter Hardware is nice but the software is not finished and has a lot of bugs with AC coupling. I will reply if the issues get resolved.

The 12wh of charging should be enough for you system. I would try the 12wk for a winter and summer and see if you really need more charging power. You will probably not want to let the batteries get bellow 20% just in case the grid goes down so at 12kw you will have 100% batteries in 3 hours.

What are some of the issues you are having? Is the comms with the SOK batteries stable? I have the same batteries and considering upgrading from a 6548 to the 18kpv

 

[djl400]

What are some of the issues you are having? Is the comms with the SOK batteries stable? I have the same batteries and considering upgrading from a 6548 to the 18kpv

The comms work with the SOK batteries but there is a bug in the inverter software that shuts off the solar that is connected directly to the inverter instead of feeding it back to the grid. I have been trying to get EG4 support to fix it since August but but haven't herd anything from them since November. You can see the green line on the trend where the solar keeps cycling on and off when the battery is full. EG4 support changed some settings and updated the firmware last year but it didn't help. The scheduled charge and discharge does not work for me also. So I can not have it automatically charge the batteries from the grid during the winter before peak hour.

Not happy with the customer support at all I would not recommend getting this inverter tell the bugs are worked out.

 

[zanydroid]

Can you get better behavior if you stop at 95%?

Is the Gen relay clicking on and off a lot? That would be the only way to curtail AC coupled inverter when on grid.

 

[djl400]

I updated the firmware, the solar shutting off when the batteries are full instead of sending the power back to the grid is fixed now. Installed two EG4 wall mount indoor batteries in parallel with the 4 SOK's and am happy with the system now. Have not done off grid tests but the normal on grid stuff working good.