EG4 18kpv stopped AC coupling

[Coopy]

Hello all,

My 18k PV stopped AC coupling this morning. Yesterday everything work great as usual. This morning around ten o’clock I checked my PV system had a warning light not connected to grid. I checked for power at the Gen Input nothing. I wasn’t sure if it was my inverter or the EG4. I reconnected my PV system back to my electrical panel and it came on. For some reason the 18k is not connecting my PV to the grid. The system has been working flawlessly. I checked the settings for AC coupling they look correct. Any ideas?

Thank you,

 

[Ampster]

AC coupling is a confusing process and I cannot tell if your problem is when the grid is down or when the grid is up? When the grid is up the GT inveters should sync to the grid and that is not technically AC coupling. What is the status now? Is the grid up?

 

[1201]

Hello all,

My 18k PV stopped AC coupling this morning. Yesterday everything work great as usual. This morning around ten o’clock I checked my PV system had a warning light not connected to grid. I checked for power at the Gen Input nothing. I wasn’t sure if it was my inverter or the EG4. I reconnected my PV system back to my electrical panel and it came on. For some reason the 18k is not connecting my PV to the grid. The system has been working flawlessly. I checked the settings for AC coupling they look correct. Any ideas?

Thank you,

Hi do you have CTs at the meter?

 

[Coopy]

Yes CT’s at the meter. The inverter is showing the back feed into the grid. There is a problem with the generator connection at the inverter not connecting with the grid.

 

[1201]

Yes CT’s at the meter. The inverter is showing the back feed into the grid. There is a problem with the generator connection at the inverter not connecting with the grid.

So with your grid tie inverter connected straight to grid and not the 18kpv , the 18kpv sees any export and diverts that to battery or loads correct?

 

[Coopy]

AC coupling is a confusing process and I cannot tell if your problem is when the grid is down or when the grid is up? When the grid is up the GT inveters should sync to the grid and that is not technically AC coupling. What is the status now? Is the grid up?

So with your grid tie inverter connected straight to grid and not the 18kpv , the 18kpv sees any export and diverts that to battery or loads correct?

no I am no longer able to charge my battery using solar through the eg4. The eg4 has two terminals for a generator feed. It can also be configured to ac couple with your existing grid tied inverter. By doing so now you can charge the battery and feed excess power to the grid through the eg4. You have to chang the settings from generator to ac coupling.

 

[1201]

no I am no longer able to charge my battery using solar through the eg4. The eg4 has two terminals for a generator feed. It can also be configured to ac couple with your existing grid tied inverter. By doing so now you can charge the battery and feed excess power to the grid through the eg4. You have to chang the settings from generator to ac coupling.

Correct I understand that but what I'm saying is that the 18kpv should be smart enough to see when your grid tie system is exporting to grid (via the CTs) and use that power to charge the battery.

You're saying it doesn't?


As far as the gen output not producing any power. Have you checked to make sure all breakers are closed?

Can you post screen shots of your current ac couple settings?

 

[Coopy]

Yes that’s what I’m saying. The CT’s are monitoring the back feed to the grid. They are located at my meter.

My eg4 is tied into the buss bar of my service panel. The way I had it wired was my Sunny Boy existing grid tied inverter was wired into the eg4 generator terminals. This way the PV ran into the eg4 then I had it set to charge the battery first then send the excess back to the grid. Everything was working fine the battery would charge then in the evening we would run off it. I didn’t change anything it just stopped working. I don’t see any breaker for the gen terminals.

 

[timselectric]

Sounds like a glitch.
First, I would cycle the gen port setting.
Second, I would try a reboot.
Good luck.

 

[1201]

Paging @EG4TechSolutionsTeam

 

[EG4TechSolutionsTeam]

The OP has sent us a DM, and we are looking into it.

 

[Coopy]

The OP has sent us a DM, and we are looking into it.

Thank you!!

 

[theonlydave]

The OP has sent us a DM, and we are looking into it.

Hi all, I will piggy back off of this thread as it is related to an 18K with AC coupling. When the grid is on it works perfectly. I managed to get the enphase system to work, having it measure the inverter LOAD as the consumption. The Microgrid is providing power to the GEN port flawlessly when the grid is on. However! when the grid goes, so does the AC coupling. I can then set it to off grid mode and the AC coupling will once again work. I need logic built into the system so that I don't have to do this manually. It would be should be something like:

When GRID present - AC Coupling with Sell Back ON then GEN PORT outputs power
When NO GRID present - Switch AC Coupling to Off Grid mode THEN GEN PORT outputs power

Two screenshots included 1 with Grid and 1 without.

Kindly let me know if this can be accomplished as the whole point of getting the 18K was to ensure the microgrid system would work constantly.

 

[Joeyjoeyjoey01]

I have a 12kpv the only way I got the ac couple no grid to work was to turn on grid sell back ..

 

[Ampster]

I have a 12kpv the only way I got the ac couple no grid to work was to turn on grid sell back

If I understood you correctly, then it was connected to the grid, which was technically not AC coupling because it was just pass through the inverter to the grid. I had to put a big load on my system to get my 8kW of Enphase micros to produce anything when the grid was down. I have not tried it when my batteries were at 60% but that creates a 5kW load that would probably be enough to fire up the micros.

 

[theonlydave]

Hi all, I will piggy back off of this thread as it is related to an 18K with AC coupling. When the grid is on it works perfectly. I managed to get the enphase system to work, having it measure the inverter LOAD as the consumption. The Microgrid is providing power to the GEN port flawlessly when the grid is on. However! when the grid goes, so does the AC coupling. I can then set it to off grid mode and the AC coupling will once again work. I need logic built into the system so that I don't have to do this manually. It would be should be something like:

When GRID present - AC Coupling with Sell Back ON then GEN PORT outputs power
When NO GRID present - Switch AC Coupling to Off Grid mode THEN GEN PORT outputs power

Two screenshots included 1 with Grid and 1 without.

Kindly let me know if this can be accomplished as the whole point of getting the 18K was to ensure the microgrid system would work constantly.

For anyone wondering, AC coupling can work with no grid on the 18K you just have to set the start % at 99% and end % at 100%.

Once this setting is set as such it enables frequency shifting, which allows AC coupling to work both with and without grid!

Below from the manual:

"After the AC couple function is enabled:
When the grid is on, the GEN terminal is connected to the GRID terminal inside the inverter. In this case,
the hybrid inverter will bypass the interactive inverter AC to the GRID and LOAD. Any remaining energy
will be exported to the grid.
When the grid is off, the GEN terminal is connected to the LOAD terminal inside the inverter. In this
case, the hybrid inverter will work as a power source for the grid-interactive inverter to synchronize
and feed power to the micro-grid. The loads will be supplied by solar power first. If solar panels are
generating more power than load consumption, the excess solar power will be stored in the batteries.
When solar power exceeds the sum of load power and max battery charging power (e.g., when the
batteries are nearly full), the inverter will signal the grid interactive inverter to reduce power via the
frequency-shifting, power-reduction mechanism, thus maintaining the balance of generation and
consumption of the micro-grid system."

Proof that it works, as you can see there is 0 volts/watts/hertz coming from the grid, yet AC coupling is on.
This is a great win for micro-grid setups.