Sol-Ark 12k AC Coupling Side Load (into sub panel) vs into Gen breaker

Highly unlikely the generator will be stable enough to satisfy the GT inverter requirements. When on generator, the SolArk is slave to generator freq/phase.

When on generator or grid input, the SolArk is not allowed to do freq shifting power control on GT inverter power output.

You could put a disconnect relay on GT feed to remove GT inverter when generator start is attempted.

RCinFLA said:

Highly unlikely the generator will be stable enough to satisfy the GT inverter requirements. When on generator, the SolArk is slave to generator freq/phase.

When on generator or grid input, the SolArk is not allowed to do freq shifting power control on GT inverter power output.

SolArk PV SCC inputs can throttle back their PV production.

You could put a disconnect relay on GT feed to remove GT inverter when generator start is attempted.

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I have a 15k but no AC coupling. From my understanding, you are correct except there is little or no frequency shift on the gen port it’s more of an on/off proposition for control of any AC coupling. So it will prioritize the AC coupling leaving it alone until it can’t. SCC does indeed throttle back as much as possible if that’s not enough then the AC couple is disconnected and the DC follows the load.

I’m pretty sure this is how they are handling the AC coupling across brands and why they are having problems with 100% AC coupling and storage.

My utility requires a 300 sec reconnect time to meet their requirements. So each disconnect take 5 min to return to production. You do the math.

Is the sol-arks AC coupling on load able to charge the batteries greater than 90% is it configurable somewhere? Mine seems to be toggling back-and-forth between 89, 90, 89, 90 and I’d just like to charge up to 98 and then shutdown for until they drop below 90

MaikaiLifeDIY said:

Is the sol-arks AC coupling on load able to charge the batteries greater than 90% is it configurable somewhere? Mine seems to be toggling back-and-forth between 89, 90, 89, 90 and I’d just like to charge up to 98 and then shutdown for until they drop below 90

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Power produced by PV has to go somewhere. If there is no grid to dump to, it must be absorbed by battery or AC output loads.

Frequency shifting control of an external GT PV inverter is slow reacting taking up to a couple of seconds to 1) SolArk recognizing the excess power by 60 Hz AC current detection, 2) SolArk shifting its frequency which it is not allowed to do too quickly 3) GT PV inverter recognizing the freq shift and cutting back its PV output power.

The situation that puts the SolArk at risk of damage is when there is no grid present to dump to and there is a lot of PV generated power being consumed by house loads. Someone turns off a significant house load, immediately creating an overproduction situation. Any excess power is immediately dumped to battery without regards for SoC of battery. If battery voltage rises beyond inverter maximum DC voltage then only option is for SolArk to shut down to save itself from damage.

Battery must be large enough AH size to take the back surge current of excess PV power generation without rising in terminal voltage too much. Common mistake is thinking you don't need a large AH battery because you have so much PV power available.

When AC coupling, most hybrid inverters will not allow a battery to be fully charged to allow some battery absorption safety margin available to absorb excess PV power until freq shifting can get excess under control.

By reconfiguring the Generator input port pass-through relay control and injecting GT PV inverter power through gen port it gives the SolArk an escape route to immediately release the gen port pass-through relay disconnecting the GT PV inverter from SolArk if it gets into an excess PV generation situation.

If the Solark is disconnecting the gen port PV, why does the ac coupled inverter need to be a grid tie inverter?

ArthurEld said:

If the Solark is disconnecting the gen port PV, why does the ac coupled inverter need to be a grid tie inverter?

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Hybrid inverter has to be AC phase sync master. PV GT inverter locks to surrogate grid source phase provided by hybrid inverter when there is no grid connection.

When SolArk is reconfigured to use generator port for PV GT inverter input, the SolArk will not attempt to sync to generator input port AC source like it would if it is configured as normal for an actual generator input.

There is reconfiguration setup required to use gen port for PV GT inverter input. You lose ability to hook up a real generator to gen port.

I am ignorant about this subject. But I think you are saying the Solark won't use the gen port unless it can sync with the frequency of the grid tied inverter or generator.
Thanks for the answer. I want to add some ac coupled PV but I am still deciding how to do it.

ArthurEld said:

If the Solark is disconnecting the gen port PV, why does the ac coupled inverter need to be a grid tie inverter?

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Grid tied inverter can export power to the grid. Sol-ark through gen port, for example.

Off-grid inverter will not backfeed the ac input (sol-ark connection). It can sync to it, like a generator, but it is designed not to backfeed and destroy the generator.

The need to absorb excess power from ac coupled systems is real. I get 1 or 2 spikes a day, especially when the evse is following solar production on a cloudy day.

Hi all, I studied this very informative(!) discussion prior to using my GEN input to expand my system. All 3 PV inputs were already full, so I built a 4.8kW array (using AP DS3 microinverters) and basically plugged it right into the Sol-ark, amazing!

But I have questions about Sol-ark behavior in this setup, hoping someone knows:
1) does the sol-ark add power from the Gen input in the daily solar production totals? It seems like maybe not, can't tell
2) in Limiter settings, I have the Grid Sell set to 9000. I thought this was a maximum value. But I watched the total grid export rise to 9500 today (might go higher in the summer sun). Anyone know why it's not limiting to 9000? does that setting only apply to the PV inputs...?
3) in the "AC in", it shows 0Hz, not 60. Seems weird.

For you question, AC coupling is what it’s called when you add more power/panels using micro inverters to gen or load inputs.

When you put these on the gen input it might not roll into the solar production but you should see it in the gen production. See page 16 of the 15k manual. It might not show on the display but maybe in the PV Pro app.

I’m not familiar with the other questions but when the batteries are full and you have AC coupling the inverter either has to change the frequency to stop the solar input or send a t somewhere else, which might explain why it’s going beyond your setting.

Again I don’t have this configuration in place but I have played around with load based AC coupling between my Enphase system and the Sol-Ark and on the load port it doesn’t report the generation at all.

Riderice said:

But I have questions about Sol-ark behavior in this setup, hoping someone knows:
1) does the sol-ark add power from the Gen input in the daily solar production totals? It seems like maybe not, can't tell

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Yes and the is the benefit of adding AC coupling through the Gen input so all you production can be monitored.

Riderice said:

2) in Limiter settings, I have the Grid Sell set to 9000. I thought this was a maximum value.,,,,,,

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The solArk can only limit its own DC coupled solar production since it would have to use frequency Watt to control the AC coupled solar. When the grid is up the frequency passes through the SolArk and it can not modify the grid frequency. The Grid Sell only applies to DC coupled output not AC coupled output.

Riderice said:

3) in the "AC in", it shows 0Hz, not 60. Seems weird.

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I have not experienced that when the grid is up. Is that in a grid down scenerio, which would seem normal if the grid is down?

@Ampster Thank you for that info!! For #1, I realized it does seem to be adding it to the daily production. For #2, yep, that makes sense. For #3, yes the grid is up...