Sol-Ark 15K All in One Inverter Released.

[Lt.Dan]

Does anybody know if there are any other features new to the 15k compared to the 12k other than the rated output?

Does anybody have any info on this? Still debating and i can't find anything other than higher output and higher pv rating.

 

[Lt.Dan]

Who's your utility? SCE? If so, line side taps appear to be allowable if they're engineered correctly, the local inspection authority confirms, and signs off on them.

https://runonsun.solar/~runons5/blogs/media/blogs/a/Line-side%20tap%20letter.pdf?mtime=1376407936

Yes, im with SCE. Like I said before, the installer is probably just trying to get out of it, and doesn't want to do it. I also am trying to keep out of running 4/0 SER for 150 feet just to get the full 200a of bypass. Im still trying to keep my costs somewhat low lol.

SolArk can only ever output 200A? To its output? Or to its input?
It can pass grid through relay to loads, probably needs 200A breaker feeding it. No issue there.

From what I can understand, the Solark 15k even with battery, pv, and grid all connected, cannot exceed 200a of output. Thus, a 200a breaker shouldn't ever exceed 100% correct?

Although I might not be understanding it all that well, as there isn't a whole lot of documentation on it.

How much current can it backfeed into grid? Something like 12kW/240V = 50A? Maybe plus AC coupled PV?
50A x 1.25 = 62.5A, feed with 70A breaker. If main panel has 200A breaker plus 70A backfed PV breaker, 270A.
If main panel has 200A busbar, 120% rule is 240A, so limit of 40A backfed PV breaker for SolArk.
If main panel has 225A busbar and 200A main breaker, 120% rule is 270A, so 70A breaker for SolArk is OK.
(But that won't take advantage of SolArk's 200A pass-through capability. What you would like is to insert SolArk between utility meter and main panel.)

The 120% rule is about current into a panel from the grid plus current into same panel from PV. With backfed PV breaker located at far end of panel there at first appears to be no issue, even if you reached 200% instead of 120%, e.g. 200A from grid and 200A from a massive PV system, because busbar doesn't every carry 400A; it carries 200A from each end in opposite directions and drops to zero A where they meet. But I have figured out that Neutral busbar could end up carrying 400A.

Yes but I think this only applies when the PV feeds the panel through its own dedicated breaker, which the 15k doesn't do. All of the PV (DC or AC coupled) runs through the inverter before going to the main panel, which means no more than 200a will ever go through it.

 

[robby]

Does anybody have any info on this? Still debating and i can't find anything other than higher output and higher pv rating.

There are no other differences that I have heard about. It's just a lot more power in every area!

 

[Lt.Dan]

There are no other differences that I have heard about. It's just a lot more power in every area!

Damn, in this case, the 12k still supports all my loads and the PV i will be using.

 

[robby]

Damn, in this case, the 12k still supports all my loads and the PV i will be using.

Get the 12K then. I am in the same boat and could upgrade but I just cannot justify it.

 

[Hedges]

Yes but I think this only applies when the PV feeds the panel through its own dedicated breaker, which the 15k doesn't do. All of the PV (DC or AC coupled) runs through the inverter before going to the main panel, which means no more than 200a will ever go through it.

Power from grid goes through 200A breaker, main panel, then through SolArk, to downstream loads.
Power from PV attached to SolArk, if backfeeding, goes through main panel, 200A breaker, to grid.

Is that what you mean?

Up to 200A from utility grid can enter one end of main panel. Whatever amperage SolArk (an AC coupled GT PV if used) produces can enter other end of main panel.
Following 120% rule, that might be max 40A breaker allowed for SolArk, 200A main breaker, for 200A load panel.
In this case, I say that only 200A will ever flow in utility L1 or L2. But I could cause 240A to flow in utility Neutral.
If 200A rather than 100A breaker used for SolArk (or 125A, the largest branch breaker I can get for my panel), then I could make 200 + 200 = 400A flow in neutral, or at least 200 + 125 = 325A. Assuming SolArk could backfeed 125A.

Is your concern you want to connect 200A breaker to SolArk because the 15k model has 200A relay, but 120% rule limits you to something like 40A?

I think a 200A 15k model is meant to go between meter and main panel. No such limit then.


"only applies when the PV feeds the panel through its own dedicated breaker, which the 15k doesn't do"

Instead of a dedicated breaker just for GT PV, SolArk is fed by a breaker which is backfed with GT PV coming out of SolArk (either directly from its PV panels or any DC coupled PV), and in addition any AC coupled GT PV you add to SolArk. But it also draws current through the breaker when grid feeds your loads. If a 200A breaker is used bidirectionally, 200A is the only limit on backfeed (assuming so much PV available.)

 

[Bits-N-Nibbles]

If you put PV array at the garage, and SolArk at the garage, you don't have any backup power for house where main panel is located.

Excuse my ignorance, but why not? I would always be backfeeding the main panel from the subpanel/Sol-Ark in garage, whether I have active grid power or it goes down, no?

 

[Ampster]

I would always be backfeeding the main panel from the subpanel/Sol-Ark in garage, whether I have active grid power or it goes down, no?

The SolArc has the automatic transfer switch to isolate from the grid when power goes down. How do you plan on isolating the Main panel from the grid when you backfeed the main panel? Are you putting the SolArc between the main breaker and the main panel? Is the main breaker at the meter and the main panel fed from there?

 

[Hedges]

Excuse my ignorance, but why not? I would always be backfeeding the main panel from the subpanel/Sol-Ark in garage, whether I have active grid power or it goes down, no?

Technically, yes, that is possible.
Not much different from a "suicide cord", an extension cord with male plugs on both ends. One goes in your generator, one in your dryer outlet. You can now power your house during a grid outage! (but you will run into problems, including possibly killing someone, if you forget to turn off main breaker. Even if the lineman survives this, when power returns it will blow up your generator.)

It is easier if the generator or inverter is near your main panel. You can install an interlocked "generator" breaker and run extension cord from generator or inverter to it. The interlock ensures you have to turn off main breaker before turning on backfed generator breaker. I have this hardwired.

It isn't so convenient for the case where SolArk is 120' away in garage. It requires a second wire run back to the main panel.

This situation is better suited to AC coupled GT PV inverter at garage, and battery inverter at the house, controlling PV inverter by frequency shift.

 

[Ampster]

This situation is better suited to AC coupled GT PV inverter at garage, and battery inverter at the house, controlling PV inverter by frequency shift

That would eliminate the need for a second set of wires from the garage to the main panel. If the SolArc were near the main panel the garage could be fed as a sub panel, The GT PV could flow back to the SolArc and serve the loads on the main panel with the balance going to the grid.

 

[Lt.Dan]

Power from grid goes through 200A breaker, main panel, then through SolArk, to downstream loads.
Power from PV attached to SolArk, if backfeeding, goes through main panel, 200A breaker, to grid.

Is that what you mean?

Up to 200A from utility grid can enter one end of main panel. Whatever amperage SolArk (an AC coupled GT PV if used) produces can enter other end of main panel.
Following 120% rule, that might be max 40A breaker allowed for SolArk, 200A main breaker, for 200A load panel.
In this case, I say that only 200A will ever flow in utility L1 or L2. But I could cause 240A to flow in utility Neutral.
If 200A rather than 100A breaker used for SolArk (or 125A, the largest branch breaker I can get for my panel), then I could make 200 + 200 = 400A flow in neutral, or at least 200 + 125 = 325A. Assuming SolArk could backfeed 125A.

Is your concern you want to connect 200A breaker to SolArk because the 15k model has 200A relay, but 120% rule limits you to something like 40A?

I think a 200A 15k model is meant to go between meter and main panel. No such limit then.


"only applies when the PV feeds the panel through its own dedicated breaker, which the 15k doesn't do"

Instead of a dedicated breaker just for GT PV, SolArk is fed by a breaker which is backfed with GT PV coming out of SolArk (either directly from its PV panels or any DC coupled PV), and in addition any AC coupled GT PV you add to SolArk. But it also draws current through the breaker when grid feeds your loads. If a 200A breaker is used bidirectionally, 200A is the only limit on backfeed (assuming so much PV available.)

I was explaining as if the Solark 15k was in between the meter and main panel, like you explained about half way down your post, which means that the only power going into the main panel would be from the sol-ark, and if it is limited to 200a, then there is no way to overload the 200a main panel. You already explained it though, I think we are on the same page.

Thanks for all the help guys, I think I'm going to continue with the design I posted in Post 349 and Post 352

 

[Ampster]

Deleted

 

[Hedges]

Im at an impasse because of the restrictions of how I have to install the inverter. This is basically my best option right now:


View attachment 100733

So because of this, I cannot fully utilize the 200a bypass, and I can't even feed everything in my home if power goes out. The sub-panel does have all the breakers for all the lights and receptacles in the home. The only thing I would want to move from the main breaker panel to the sub panel is the refrigerator (dunno why its not in the sub panel already, the refrigerator is less than 20 feet away from the sub panel, but its about 80 feet from the main panel?).

So because of this, I'm thinking about going with the 12k. But is it worth it to just spend the extra ~$1300 and get the 15k?

EDIT: I'm also in California, where I'm going to most likely have to wait until August (more than likely even later than that) to even get permits approved to install it. Whereas the 12k I can get installed right now.

In this drawing, you have 100A backfed breaker (for SolArk) next to 200A main breaker in main panel.
Grid can feed 200A into the panel, SolArk can feed 100A, 300A can flow through busbars of main panel to loads.
1.5x rated current, 1.5^2 = 2.25x the heating and temperature rise.
This is why 120% rule, and why backfed breaker belongs at far end of panel.
(But I've figured out how to overload the neutral bar even with backfed breaker at far end.)

 

[Lt.Dan]

In this drawing, you have 100A backfed breaker (for SolArk) next to 200A main breaker in main panel.
Grid can feed 200A into the panel, SolArk can feed 100A, 300A can flow through busbars of main panel to loads.
1.5x rated current, 1.5^2 = 2.25x the heating and temperature rise.
This is why 120% rule, and why backfed breaker belongs at far end of panel.
(But I've figured out how to overload the neutral bar even with backfed breaker at far end.)

Ooh you are right, I originally drew that when I was going to use the 15k which would then require a breaker derating, but now I am using the 12k. The manual for the Sol-Ark 12k shows the continuous AC power to grid is 37.5a. This means 200a+37.5a is less than 240a total, which means we are under the 120% rule. But just barely.

 

[Lt.Dan]

Ooh you are right, I originally drew that when I was going to use the 15k which would then require a breaker derating, but now I am using the 12k. The manual for the Sol-Ark 12k shows the continuous AC power to grid is 37.5a. This means 200a+37.5a is less than 240a total, which means we are under the 120% rule. But just barely.

Hmm, now I guess here is another question that is probably a gray area:

I will have an 11kw solar array on the house, which is 48.83a @ 240v. Now this will exceed the 120% rule by 8.83a. BUT, if the inverter is only capable of sending 37.5a to the grid, does this mean I am technically under the 120% rule?

Does the electric company care about the actual solar array output? Or the legitimate load that can be placed on the electrical panel itself? These are 2 very different things.

 

[Ampster]

Does the electric company care about the actual solar array output? Or the legitimate load that can be placed on the electrical panel itself? These are 2 very different things.

In most jurisdictions, the AHJ only care about what is behind the meter which includes the 120% rule but Hedges has given you some workarounds for that. All the electric company is concerned with is the capacity that is going to go back to the grid. Behind the meter you have more flexibilty with anything that is not going back through the meter to the grid I presume the Solark can limit what goes back to the grid. So if you have 6kW of grid tie solar but another 6kW DC coupled to the SolArk you can tell the SolArk to only export 6KW but you have the benefit of a 12 kW system.

The 120% rule can be figured out with Sub panels so do not worry about that rule as a constraint.

 

[Balthazar-B]

In most jurisdictions, the AHJ only care about what is behind the meter which includes the 120% rule but Hedges has given you some workarounds for that. All the electric company is concerned with is the capacity that is going to go back to the grid. Behind the meter you have more flexibilty with anything that is not going back through the meter to the grid I presume the Solark can limit what goes back to the grid. So if you have 6kW of grid tie solar but another 6kW DC coupled to the SolArk you can tell the SolArk to only export 6KW but you have the benefit of a 12 kW system.

The 120% rule can be figured out with Sub panels so do not worry about that rule as a constraint.

Both the 12K and 15K are configurable with an upper limit to what is backfed to the grid. As well as manage the balance between production and load demand.

 

[Hedges]

The manual for the Sol-Ark 12k shows the continuous AC power to grid is 37.5a. This means 200a+37.5a is less than 240a total, which means we are under the 120% rule. But just barely.

I will have an 11kw solar array on the house, which is 48.83a @ 240v. Now this will exceed the 120% rule by 8.83a. BUT, if the inverter is only capable of sending 37.5a to the grid, does this mean I am technically under the 120% rule?

The rule is breaker size, not actual amps drawn.
Of course, busbar heating from actual amps. Adequate from an ampacity perspective but not code. So as Balthazar says the export current could be programmed low enough while allowing more import. (Maybe not programmed lower than any AC coupled PV.)

I used to have mine connected through Square-D QO panel, which has 225A busbar and 200A main. That allowed 70A backfed breaker for PV (and Sunny Island)

Now I have something like a line-side tap, except that there is another 200A breaker right after the meter. No more than 200A can enter 2/0 wire connector from grid, no more than 100A more can enter it from fused disconnect for Sunny Islands, but no more than 200A can enter main panel, because all branches have OCP. There would be 300A available to a length of wire, but it can only short to enclosure (tripping OCP) or feed a 200A breaker.

It is possible to have more than 3 branches. In that case, if multiple forks occurred in the wire, a length could exceed 200A, would need larger gauge for that section. But with a 400A rated Polaris connector, could have 5 branches in a star or "Y" connection and all wires are protected. (Unlike a busbar, which daisy-chains many loads. The Polaris is the busbar.)

With a line-side tap, load on their wires is sum of the multiple circuits (except if there is one more breaker at the meter.) When line-side tap is only GT PV, only decreases current doesn't increase. With a battery inverter & loads, utility wires could cause sum of both.

Does the electric company care about the actual solar array output? Or the legitimate load that can be placed on the electrical panel itself? These are 2 very different things.

Solar array & inverter they put limits. Generation has to match load, and excessive consumer PV is unregulated, can destabilize grid. So they have limits.

Load of course is current, and usually adds up to more than PV generation.

A utility transformer can be fused on the primary, protecting transformer and wires downstream.
Sum of consumer 200A breaker panels may exceed capacity, but not all at 100% load at same time, and if they are fuses protect.
If enough consumer PV connected, say 70A per panel, all that power plus transformer are available to feed wires to houses further from transformer. This can exceed, in the wires, what 120% rule would limit panels to. And it isn't at far end of the wires. A utility run down the street could have 200%, twice the current available to it that it can carry. If consumer load aren't balanced between L1 and L2, the Neutral wire can carry more than Line; 2x the 240V current from PV plus current from transformer.

 

[Wet1]

But using the SA software to limit the back-feed gets back to that same concern that was recently mentioned in the microinveeter thread. Some power companies might have an issue with that. (Not that Im agreeing with them, but i get their agruement.)

 

[niktak11]

I finally did some off-grid load testing of my unit. The hardest test was starting my 3HP well pump while powering 3 upright freezers and charging my car at 32A. During startup that should be around 100A total at 240V. It started it up fine although I only did that once. The one surprising thing is that the output voltage reported by the Sol-Ark itself was only 215V even while the load had settled down to 52A or so. My incoming PV was over 3kW so that was only at about 75% of the stated max output specs.