Sounds about rightOk so when grid is up the gen is connected to grid which is connected to load?
So all three are connected together. Otherwise it would be impossible for load to get power from ac coupled pv while on grid
Sounds about rightOk so when grid is up the gen is connected to grid which is connected to load?
So all three are connected together. Otherwise it would be impossible for load to get power from ac coupled pv while on grid
That sounds like a good solution and consistent with what my SolArk does, subject to the limitations of total throughput determined by the breaker serving the inverter. Thanks for the update.the AC coupled array should be able to sum to the 12 kwh....and the grid as well.....).....
With AC Couple, you get up to 12 PV from the 18, all of the PV from AC Coupled system and grid.Right after the first email exchange explaining my actual config, what i do plan to add and my goals, SS told me that AC coupling with the GEn port was the solution. They did not offer any alternatives. Now, i am waiting for the feedback of the representatives after they told me about the weird limitation of the 12 kwh of power no matter what (because as Millsan1 said, the 12 kwh limit is for the inverted power.....the AC coupled array should be able to sum to the 12 kwh....and the grid as well.....).....
Right after the first email exchange explaining my actual config, what i do plan to add and my goals, SS told me that AC coupling with the GEn port was the solution. They did not offer any alternatives. Now, i am waiting for the feedback of the representatives after they told me about the weird limitation of the 12 kwh of power no matter what (because as Millsan1 said, the 12 kwh limit is for the inverted power.....the AC coupled array should be able to sum to the 12 kwh....and the grid as well.....).....
I think the op thinks that if you have ac coupling on the gen port then that power is not available to the loads port.So as I RTFM . . . If you AC-couple you get up to 90A of cruft from the micro-inverters + another 50A from the PV. The only limitation is PV->grid which is 50A (12KW). Thus assuming you have a beast set of micro-inverters, and direct PV coming out your behind, with a single 18kpv you can push 30+KW back towards the grid lugs/panel. Assuming you've properly configured your export settings and installed the CT's properly you should be golden.
I'm not sure where the problem is, perhaps there is a mis-communication as the thread gets deep. Put the Enphase stuff on the gen lugs, turn on AC coupling. You have access to all the power, sans any direct PV over 12K, which can go to the batteries I think. Do you actually have > 12KW of direct panel output on a single unit?
At some point you have to buy more hardware and/or re-engineer, and frankly I would never run my stuff constantly at the edge of it's capability. YMMV. My 32 panel array of 4x8x455w has hit over 12, theoretically it's a little under 15, but I have it split between two. I mean if you want to mix 20 different types of solar equipment more power to you but you seemed to indicate you have ~18K of micro-inverter stuff, which should work in cahoots with the 18kpv as documented in the manual. If you are trying to get creative and use it in an undocumented manner, that is generally unwise.
From the manual:
View attachment 205165
Not what the issue is.I think the op things that if you have ac coupling on the gen port they that power is not available to the loads port.
That's wrong of course but op says that's what ss is telling them
Power can't be limited to 12kw if ac coupled.Not what the issue is.
Power is limited to 12Kw when AC coupled to the gen port.
The reason? A relay is present on the gen port to cut power from the AC coupled GT array as frequency shift isn't fast enough. The relay is limited to 12Kw.
That is how I see it. And Hedges explained it here.
I know from testing the gen ports can (will) bridge to load/grid/bus with relays. So, power to the load lugs should be limited to ~50A, but not to the grid side/backfeed. The inverter was engineered to deliver 50A to the load lugs (12klv). If you need more than that you would want to parallel units. More of an engineering issue. If your critical loads panel is > 50A, you'll neet to get more AIO's. That output is not designed to be shared with another power source unless it's another eg4 inverter. You might get it to work with something else, but you may run into phasing issues.Not what the issue is.
Power is limited to 12Kw when AC coupled to the gen port.
The reason? A relay is present on the gen port to cut power from the AC coupled GT array as frequency shift isn't fast enough. The relay is limited to 12Kw.
That is how I see it. And Hedges explained it here.
I know from testing the gen ports can (will) bridge to load/grid/bus with relays. So, power to the load lugs should be limited to ~50A, but not to the grid side/backfeed. The inverter was engineered to deliver 50A to the load lugs (12klv). If you need more than that you would want to parallel units. More of an engineering issue. If your critical loads panel is > 50A, you'll neet to get more AIO's. That output is not designed to be shared with another power source unless it's another eg4 inverter. You might get it to work with something else, but you may run into phasing issues.
If you are just trying to save money you can dump all of the excess back to the grid side and whatever you have connected there.
The inverter was engineered to deliver 50A to the load lugs (12klv). If you need more than that you would want to parallel units.
The 18Kpv shifts frequency to reduce power from the AC coupled inverters only when grid is off.
Ok- the grid is on, export is enabled- and there is 18kw of ac coupled power at the gen port. There is 14kw of load at the load port - what happens?The 18Kpv shifts frequency to reduce power from the AC coupled inverters only when grid is off.
However, when grid is on, grid controls the frequency and thus the 18Kpv can only reduce power from AC coupling by turning off the relay in the generator port.
@FilterGuy explains it in this post.
Ok- the grid is on, export is enabled- and there is 18kw of ac coupled power at the gen port. There is 14kw of load at the load port - what happens?
What do you mean? I posed a scenario and asked a question. I'm waiting for your thoughts on what you believe would happen in that scenario."EG4 just told me (and thanks for them for being honest) that in that case the system can not use the 200 amp pass through when ac coupled and then you are always limited to....12 kwh output of the 18K....and that you can not export to the grid as well because "The 18K has a 2 poles internal relay that switches back and forth btw GRID IN, GEN IN and LOAD OUT. It is able to utilize 2 of these simultaneously : GRID/GEN (well you can only charge up batteries then, not your load...), GRID/LOAD (ok but then the 9.75 kwh array power....is lost) or GEN/LOAD (Nice you enjoy the power of the grid tie system, the new system.....but are limited to 12 kwh of total output....)"
So, which 2 relays will be switched on?
Ok- the grid is on, export is enabled- and there is 18kw of ac coupled power at the gen port. There is 14kw of load at the load port - what happens?
Thanks for clarifying a few important thingsI will assume the inverter is configured for AC coupling at the Gen port.
In this case, the 4K of 'extra' power from the AC coupling will be used for charging the battery and/or exporting to the grid....depending on other settings in the system. (The good news is that the 18Kpv is highly configurable. The bad news is that the answers to seemingly simple questions have to be qualified with the dependency on the configuration)
I assume the above is all about KW, not KWh.Grid is ON, total load is 15 kwh, ac coupled array is giving 3 kwh, 18k array is giving 5 kwh and batteries are dead or at SOC that does not permit any power draw. What happen ? Does the 18k can draw power from the grid in grid assist kind of mode ?
If you have zero Export on and the grid is up, the AC coupling will be turned completely off. 8KW will be going to the load and up to 7KW will go to charging the battery. If the battery can not take the whole 7KW, the MPPT will throttle the 18K array down to whatever is needed by the load and the battery.Case 2 : Grid export is NOT permitted.
Grid is ON, total load is 8 kwh, AC coupled array is giving 7 kwh, 18k array 15 kw what is happening ?
In this case, the 4KW from the arrays will go to the load and an additional 2KW will come from the Grid. The system will also be able to charge the batteries from the grid at the same time. (Assuming the system is configured to charge the batteries from the grid)If load is 6 kwh, AC couple array is giving 1 kwh, 18 k array 3 kwh and batteries are dead, does the grid assist works ?
And if the loads are low enough all the AC coupled solar plus some of the 12kW from the inverter that doesn't have to cover remaining solar gets exported. Is that correct?then that power as available for loads in addition to the 12kw of the inverter
That's correct. Assuming battery is full it will sell the ac couple power up to 21.6kw plus excess DC couple pv up to 12kw to the grid.And if the loads are low enough all the AC coupled solar plus some of the 12kW from the inverter that doesn't have to cover remaining solar gets exported. Is that correct?