Sol-Ark 12k Max Continuous AC On-Grid

[chuckyboy81070]

Hi everyone,

I'm still researching stuff. This forum has been very helpful.

The spec sheet for the Sol-Ark 12k states 15120W 63A L-L (240V) for the Max Continuous AC On-Grid (or generator) and a Surge AC Power (10 Seconds) of 16,000VA L-L (240V).

Forgive the beginner question, but does that mean that even while the grid is connected and functional, that any draw above that value could potentially overload the inverter?

Our house here in Texas has a 5-ton ac unit (soft-start), electric oven, and induction stovetop. The dryer is gas. While the grid was on and I were to be cooking a multi-burner dinner on the stovetop while baking a turkey and the air conditioner running (a pretty common combo during the summer), am I rolling the dice if you take into account the additional power draw coming from the rest of the house that could itself be 2 or 3 kW?

Only the 120v stuff would be on the critical load subpanel, if that matters.

 

[Lt.Dan]

Anything over the 15120w load will trip an overcurrent fault and shut down. If you are worried about tripping it because the AC, then I would move it to a separate panel that is power from the grid, and have a "Critical loads" panel that the Sol-Ark powers.

That is how mine is wired.

 

[chuckyboy81070]

I wanted to avoid moving the AC to a grid-only panel for the simple reason that the air conditioner is responsible for well over half of the monthly electric draw for 2 or 3 months out of the year. It's a relatively new (2 years old) and efficient unit, but it's very hot and very humid here in Houston. It seems that keeping it on the grid would still amount to a sizeable monthly electric bill for a few months. The solar buy back options here are pretty weak so even though I would be able to sell back the extra energy from PV, the return is not that much. But maybe I need to redo the math.

Would the Sol-Ark 15K still have that ceiling since it has that 200A breaker and can sit between the meter and breaker box? And does that complicate subpanel issue of just having the 120v stuff on critical load?

 

[zanydroid]

I'm pretty sure all the SolArks are able to use CTs (current transformer) to push out power to compensate for power demands from a grid only panel that is sitting on the correct side of the CT relative to the inverter. If wired appropriately, in terms of where you put the CT sensors and the loads. In this way there cannot be an overload situation.

The limitations would be that these loads would not be available when running with grid down. Unless you add some external switches to switch the loads to the critical loads panel in an emergency. Also if your instantaneous demand exceeds the AC out of the inverter you can't compensate it, but I hardly think this will affect your ROI.

 

[Lt.Dan]

I'm pretty sure all the SolArks are able to use CTs (current transformer) to push out power to compensate for power demands from a grid only panel that is sitting on the correct side of the CT relative to the inverter. If wired appropriately, in terms of where you put the CT sensors and the loads. In this way there cannot be an overload situation.

The limitations would be that these loads would not be available when running with grid down. Unless you add some external switches to switch the loads to the critical loads panel in an emergency. Also if your instantaneous demand exceeds the AC out of the inverter you can't compensate it, but I hardly think this will affect your ROI.

This is exactly how mine is. This way when the AC kicks on, the surge is taken care of by the grid, but the SolArk can backfeed the same amount the AC is drawing. If the backfeed is greater than the inverters output, the inverter will just output its max, and the grid will supply for the rest.

My house has routinely seen 20kW load in the last few months with AC usage, car charging, clothes drier, etc, and the SolArk just maxes out at 9kW and the rest comes from grid.

 

[chuckyboy81070]

I have to admit the use of "AC" for two things has thrown me a little bit.

 

[chuckyboy81070]

This is exactly how mine is. This way when the AC kicks on, the surge is taken care of by the grid, but the SolArk can backfeed the same amount the AC is drawing. If the backfeed is greater than the inverters output, the inverter will just output its max, and the grid will supply for the rest.

My house has routinely seen 20kW load in the last few months with AC usage, car charging, clothes drier, etc, and the SolArk just maxes out at 9kW and the rest comes from grid.

Hi @Lt.Dan Would you mind describing yours in more detail? I think I follow what is being described, but I want to be sure. If I can get away with using the 8K and not risk overloading it, then that would be OK. My air conditioner, stovetop, and oven would probably be the only things not on the critical loads panel.

I'm also willing to go with the 15K if that makes everything easier. I just feel like it may be overkill, but the very fact that I'm asking this question may mean it's not.

 

[Lt.Dan]

Hi @Lt.Dan Would you mind describing yours in more detail? I think I follow what is being described, but I want to be sure. If I can get away with using the 8K and not risk overloading it, then that would be OK. My air conditioner, stovetop, and oven would probably be the only things not on the critical loads panel.

I'm also willing to go with the 12K if that makes everything easier. I just feel like it may be overkill, but the very fact that I'm asking this question may mean it's not.

This is exactly how mine is wired. The critical loads sub panel was already in my garage, with all my light loads, outlets, and lights on it. The main panel just has the heavy 240v loads, such as the Air Conditioner, Clothes Drier, Hot tub, etc. This means that in the event of a power outage, I will only be able to have power at the critical loads panel.

 

[DIYrich]

Get the 15k and don't worry about it. It also comes with an isolation circuit so it can island when grid down. If price is an issue, go with the eg4 18kpv.

 

[Bkord]

I have an all electric house, and a 12k sol ark. Half the house is on a critical loads panel, the other half is the main. I have not had an electric bill in 4 months. I am net metering but the sol ark can back feed the main without exporting to the grid. I think it’s called “limit to home”

 

[Solar Newbee]

Lt. Dan, in the diagram above that you showed, is the critical loads sub panel connected back to the main breaker panel directly or is the connection made thru the Sol-Ark( I'm new to Sol-Ark)? Does the Sol-Ark act as a transfer switch between the main breaker panel and the critical loads sub panel?

 

[Lt.Dan]

Lt. Dan, in the diagram above that you showed, is the critical loads sub panel connected back to the main breaker panel directly or is the connection made thru the Sol-Ark( I'm new to Sol-Ark)? Does the Sol-Ark act as a transfer switch between the main breaker panel and the critical loads sub panel?

The sub panel does not connect back to the main. The power is fed through the SolArk and it has an internal transfer switch.

 

[Solar Newbee]

So presently, my friend has AC from the grid coming into his home. So the setup diagram (from Sol-Ark) to follow is AC coupling?

Can this Sol-Ark be setup in an off grid setup?

 

[BrianVeg]

@Lt.Dan Love the diagram. It’s something I think I want model. I’m confused by the generator connection. What is connected to the junction box in the lower right?

 

[Lt.Dan]

@Lt.Dan Love the diagram. It’s something I think I want model. I’m confused by the generator connection. What is connected to the junction box in the lower right?

Thanks, the diagram isn't mine, its out of the Sol-Ark 12k manual. The generator input is the AC Coupled PV. In this diagram its called a "Junction Box", but in my actual use case, its a Growatt Grid Tie Inverter. The black line across the top:


Is just the daisy chain cables that typically go from Microinverter-to-Microinverter.

Did that answer your question?

 

[Nobodybusiness]

Hi everyone,

I'm still researching stuff. This forum has been very helpful.

The spec sheet for the Sol-Ark 12k states 15120W 63A L-L (240V) for the Max Continuous AC On-Grid (or generator) and a Surge AC Power (10 Seconds) of 16,000VA L-L (240V).

Forgive the beginner question, but does that mean that even while the grid is connected and functional, that any draw above that value could potentially overload the inverter?

Our house here in Texas has a 5-ton ac unit (soft-start), electric oven, and induction stovetop. The dryer is gas. While the grid was on and I were to be cooking a multi-burner dinner on the stovetop while baking a turkey and the air conditioner running (a pretty common combo during the summer), am I rolling the dice if you take into account the additional power draw coming from the rest of the house that could itself be 2 or 3 kW?

Only the 120v stuff would be on the critical load subpanel, if that matters.

For a few dollars more I would get the 15k unless you already have the 12k.

 

[BrianVeg]

Thanks, the diagram isn't mine, its out of the Sol-Ark 12k manual. The generator input is the AC Coupled PV. In this diagram its called a "Junction Box", but in my actual use case, its a Growatt Grid Tie Inverter. The black line across the top:
View attachment 170654

Is just the daisy chain cables that typically go from Microinverter-to-Microinverter.

Did that answer your question?

Yes - thank you!

 

[BrianVeg]

I’ve spent most of my time researching Victron 5K and Charge Controller ans then I’ve come to realize a Sol-Ark 15k would give me more and cost less.

Didn‘t know.

Time to switch gears.

 

[zanydroid]

I’ve spent most of my time researching Victron 5K and Charge Controller ans then I’ve come to realize a Sol-Ark 15k would give me more and cost less.

Didn‘t know.

Time to switch gears.

I mean in the US buying victron also means you pay extra for the privilege of not having gear capable of being 100% on-grid, residential structure code compliant, so there’s a lot of reasons to be skeptical of victron this side of the pond.

 

[BrianVeg]

@Lt.Dan Looking at the diagram you/Sol-Ark provided I created my own. Doing a drawing like this helps me figure things out. Phase 1 will be Battery's. I'm trying to solve for two things with Phase 1:

1. Protect against power outages
2. Reduce electric costs by using batteries when electric rates are high

I'd like to run as much of the critical loads panel during the day off of battery power and use the grid to charge the batteries at night when electricity is cheaper.

I will add Solar Panels in Phase 2.

Thoughts?