Sol-Ark 15k Install Recommendations

[Idratherski]

Hi,

I am looking for recommendations on Sol-Ark 15K installation configuration for my situation.

My starting configuration and goals are:

My installer configured the system as shown here:

I am not certain this is the best configuration for my situation because I am not able to enable “Limit to Home” mode because the CT sensors are not installed. Also, the Fronius 5kW is not available when the grid is down and I am not able to load Panel #1 when the grid is down.
To improve this, I am thinking that it should be configured as shown below. What do the experts here think? How would you configure this to best achieve my goals?

Thanks for any help,
Mark

 

[Danke]

What service do you have 200 amp 400 amp?

Sol-Ark has 200 amp pass-through, so I’m not sure why you separate two main panels with one coming directly from the grid.

 

[Idratherski]

I *believe* that I have a 400A service which is why there are (2) 200A main panels in my house prior to the upgrade. Are you asking why my 200A main panel #1 is on the grid side of the Sol-Ark while the critical loads panel is on the load side? Since the Sol-Ark has a 200A feed through, this is the same question I am asking myself and the installer. Why shouldn’t I put the main panel # 1 on the load side as shown in my proposed redline diagram. This change allows the main panel #1 loads to be powered during grid down by the solar and/or battery. This also makes the loads on main#1 to be sensed by the Sol-Ark.

I may be misunderstanding your question.

 

[Danke]

Why not put the grid into the ATS along with the generator. And ATS out going to the Sol-Ark grid input?

Or is ATS limited to only 80amps, not a 200amp ATS?

 

[Idratherski]

Correct, the ATS I have is rated for 80A.

I think that would be better though. It would allow for generator supply to the 200A panel and allow the generator to charge batteries through the Sol-Ark for grid-down situations.

 

[Think About It]

I'd like to commend you for posting those diagrams.

When you say "increase solar to 20KW" is that the ideal (max) capacity? Sol-Ark 15 can handle 19,500 W of PV. Why not connect all the PV directly to the Sol-Ark?

Since you are going to have batteries and a generator, why not do away with the "Critical Loads" panel and tie the generator into the Gen port of the Sol-Ark?

Some users prefer to put their generator and a 200A auto x-fer switch ahead of the Sol-Ark in line with the grid.

I put my gen on the gen port. I repurposed my 200A auto-transfer switch to a manual x-fer switch and use to bypass the Sol-Ark if I ever need to. This is strongly recommended.

 

[Idratherski]

Thanks, Think About It, the diagrams make it much easier to discuss.

Yes, in theory the Sol-Ark max PV input would allow the addition of my original 5kW of PV to be DC coupled into it. The only reason I didn’t do it that way was to avoid having to touch any of the existing wiring from the 5kW array (which is in a completely different location on the property) by AC coupling it instead. Also, stringing the 5kW array (which is older different panels) together with the new 16kW might have been difficult since I am using all of the MPPT inputs for the new 16kW array. The AC coupling capability of the Sol-Ark was one of the reasons I wanted to use the Sol-Ark.

I like the idea of using the Sol-Ark GEN input for the generator which would also eliminate the ATS by using the Sol-Ark, however, that means I need another way to couple the old 5kW array. If I understand the Sol-Ark manual correctly, I can’t use the GEN input at all if I AC couple the 5kW array per this diagram below.

I also like the idea of putting the generator with a transfer switch on the grid input of the Sol-Ark. As I said earlier, my only issue is that this requires me to upgrade the ATS from 80A to 200A.

Regarding the manual bypass of the Sol-Ark, is it common to have problems with the Sol-Ark requiring use of the bypass? In my current configuration, if I had a problem with the Sol-Ark, I could run on just my critical loads panel by manually actuating the ATS until I got the Sol-Ark fixed. That wouldn’t work for my proposed configuration and would need an additional manual bypass, as you are recommending. I will have to think about adding that.

 

[Danke]

For my set up, I’m using distribution blocks. I feed my circuit breaker panels from those distribution boxes. So if I ever need to remove the Sol-Ark, I just put the L1 & L2 wires that were going into the Sol-Ark and feed them into the those distribution blocks directly.

 

[Think About It]

I like the idea of using the Sol-Ark GEN input for the generator which would also eliminate the ATS by using the Sol-Ark, however, that means I need another way to couple the old 5kW array. If I understand the Sol-Ark manual correctly, I can’t use the GEN input at all if I AC couple the 5kW array per this diagram below.

You could either leave your existing AC Coupled Inverter as is - Main Load Center #1, or connect it into Main Load Center #2. This would leave the Gen port open for the Generator.

Again, I'm not sure that you need a "Critical Loads" panel.

 

[RCinFLA]

It is good idea to have the ability to bypass inverter if something goes wrong with inverter and there is no pass-through power. I am talking about a setup that a non-technical person can do with simple instructions over the phone or following a posted instruction sheet by inverter, in case you are not there.

 

[Think About It]

Regarding the manual bypass of the Sol-Ark, is it common to have problems with the Sol-Ark requiring use of the bypass?

No, it's not common. With the bypass in place, the Sol-Ark still has Grid power, software updates can be done. In fact, the software updates take a while and then the Inverter reboots. So power is interrupted for a little bit.

When you are away at Vail, CO skiing and something happens to your inverter, as @RCinFLA says, you want something very simple that anyone could use to bypass the inverter. Otherwise your ski trip could be cut short.

 

[Idratherski]

No, it's not common. With the bypass in place, the Sol-Ark still has Grid power, software updates can be done. In fact, the software updates take a while and then the Inverter reboots. So power is interrupted for a little bit.

When you are away at Vail, CO skiing and something happens to your inverter, as @RCinFLA says, you want something very simple that anyone could use to bypass the inverter. Otherwise your ski trip could be cut short.

After some thought about a manual bypass, I think it is not a must-have because in that kind of emergency, I can turn off the input to the ATS and run on the generator to repair the Sol-Ark. I think this would only be a serious problem if repairing or replacing the Sol-Ark was going to take a long time.

Thanks for all the advice — super helpful.

 

[Idratherski]

You could either leave your existing AC Coupled Inverter as is - Main Load Center #1, or connect it into Main Load Center #2. This would leave the Gen port open for the Generator.

Unless I am misunderstanding the Sol-Ark manual, I cannot AC couple to the load side of the Sol-Ark AND use the GEN connection.

I can, however, AC couple to the grid side (my current config) of the Sol-Ark AND use the GEN connection. The drawback of this is that the 5kW PV is not available to charge batteries when the grid is down and the 5kW PV is not measured by the Sol-Ark.

 

[Think About It]

Unless I am misunderstanding the Sol-Ark manual, I cannot AC couple to the load side of the Sol-Ark AND use the GEN connection.

Correct, I forgot about that. Can't use Gen port with AC Coupling on Load side.

 

[RCinFLA]

The Grid port and Gen port have just two independent pass-through relays to inverter/AC output connection along with AC voltage and current sensing on each port.

In normal operation, only one port is allowed to be active and default is Grid port if there is AC present on it. Current sensing on Gen port will prevent backfeeding a generator.

For AC coupling mode into Gen port the SolArk is just using the Gen input pass-through relay to provide a quick disconnect from grid tie inverter if SolArc inverter gets into trouble from too much sudden PV overgeneration.

This can happen during no grid presence or off grid if you have a heavy house load that is switched off while PV is producing a lot of power. The freq shifting cannot react fast enough to avoid inverter damage so SolArk 'pulls the plug' on grid tie inverter by opening Gen relay. If you AC couple connect grid tie inverter directly to inverter AC output you lose this quick disconnect safety feature for sudden overproduction.

You give up generator input when using Gen input port for grid tie inverter AC coupling input. I would not recommend injecting AC coupled grid tie inverter directly to AC output of inverter unless the PV array is less then one or two kW's. In the worst case the battery has to suck up any excess PV power for the time it takes for freq shifting to get grid tie inverter to reduce its power. If battery is too full it can cause inverter overvoltage on battery DC input causing a shutdown.

 

[Idratherski]

The Grid port and Gen port have just two independent pass-through relays to inverter/AC output connection along with AC voltage and current sensing on each port.

In normal operation, only one port is allowed to be active and default is Grid port if there is AC present on it. Current sensing on Gen port will prevent backfeeding a generator.

For AC coupling mode into Gen port the SolArk is just using the Gen input pass-through relay to provide a quick disconnect from grid tie inverter if inverter gets into trouble from too much sudden PV overgeneration.

This can happen during no grid presence or off grid if you have a heavy house load that is switched off while PV is producing a lot of power. The freq shifting cannot react fast enough to avoid inverter damage so SolArk 'pulls the plug' on grid tie inverter by opening Gen relay. If you AC couple connect grid tie inverter directly to inverter AC output you lose this quick disconnect safety feature for sudden overproduction.

You give up generator input when using Gen input port for grid tie inverter AC coupling input. I would not recommend injecting AC coupled grid tie inverter directly to AC output of inverter unless the PV array is less then one or two kW's. In the worst case the battery has to suck up any excess PV power for a the time it takes for freq shifting to get grid tie inverter to reduce its power. If battery is too full it can cause inverter overvoltage on battery DC input causing a shutdown.

Thanks for that explanation, very helpful to understand how the Sol-Ark works.