I'm thinking of buying the EG4 18k

[rebelrider.mike]

I was all set to buy a different inverter, and found out it didn't have ground fault detection or arc fault interrupt. But the EG4 18k does, and is only just outside my price range, LOL.

The manual is pretty vague about the unit's rapid shutdown capability. Fortunately, EG4 released this video a few days ago:

I guess the fellow is saying that there is a Tigo-compatible RSD transmitter built into the inverter? I'm guessing that it sends the "all clear" signal out through the PV conductors like the Tigo RSD transmitter would do. I'm thinking of getting the CCA, TAP, and the TS4-A-O modules, so that video helped a little. Though, I don't follow exactly how he hooked up the inverters RSD button to the external one, or why.

I'm also following the zero export issue here with interest. I haven't decided whether to sell back to my utility or not. But I do want grid input for when solar isn't plentiful. I'll be outputting to a sub panel rather than the main panel. I needed a sub panel anyway. My old breaker box is full of new breakers as I upgrade the wiring in my house. Ironic, because I'm actually using less electricity as I make those same improvements.

Something I'm not sure of is whether or not this inverter can use solar and grid to power the load at the same time, or if it switches back and forth. From what I've seen, most inverters share the load if solar is not sufficient (at least that's one possible setting). The language in the manual for self-usage mode is this:

"When solar power is not enough to take the load, the solar and battery will take the load together. If the battery is empty, the grid will be used to power the loads."

"Take the load together" vs "the grid will be used". The grid will be used to supplement the solar, or used instead of the solar? Either way, I'm not sure its a deal breaker. More of a curiosity.

 

[FilterGuy]

Though, I don't follow exactly how he hooked up the inverters RSD button to the external one, or why.

They published a paper to go along with the video.

https://eg4electronics.com/wp-content/uploads/2023/08/External-RSD-Switch-Install-v1.01.pdf

The reason to tie it into the inverter is to ensure the inverter does a rapid shutdown at the same time. (Rapid requires shutdown of the AC in some areas).

Something I'm not sure of is whether or not this inverter can use solar and grid to power the load at the same time, or if it switches back and forth. From what I've seen, most inverters share the load if solar is not sufficient (at least that's one possible setting). The language in the manual for self-usage mode is this:

Yes, it is a hybrid inverter and as such it can either fully power the loads by itself or supplement the power coming from the grid.

 

[DIYrich]

I guess the fellow is saying that there is a Tigo-compatible RSD transmitter built into the inverter? I'm guessing that it sends the "all clear" signal out through the PV conductors like the Tigo RSD transmitter would do. I'm thinking of getting the CCA, TAP, and the TS4-A-O modules, so that video helped a little. Though, I don't follow exactly how he hooked up the inverters RSD button to the external one, or why.

A loss of power to the CCA initiates the rapid shutdown. So, wire the power to the CCA on a circuit that would be turned off when RSD is activated. I think the 12v (20v?) off the 18kpv would turn off during RSD. If so, you can use that to power the CCA. TS4-A-O gets the signal from the CCA via the TAP.

 

[rebelrider.mike]

Fantastic! Thanks for the info guys. I see now on their website the link to the RSD paper. So the 24V to which they recommend connecting the CCA, will get its power from the battery. I did not understand before what a "dark start" issue was.

 

[DIYrich]

Dark start is when there is no power available to turn on the CCA so it can tell the panels to turn on. Happens when the inverter turns off when the battery gets low. In that instance the inverter turns off ac, but maintains power to the 24v connector. That assumes there is battery power left. If the bms turns off, then you need to activate the emergency override on the bms to turn on the battery, so it can power the CCA, so it can tell the panels to turn on.

 

[rebelrider.mike]

Just saw the new EG4 wall mounted battery. It may simplify my project quite a bit. I'm looking forward to seeing how it works with the 18k inverter. I hope its as good as its advertised to be.