EG4 18KPV Design/Configuration Help for 16,000kWh PV, 400A service, new build, Net Zero Home in Vancouver, BC

[NovicePV]

Hi everyone,
Lots of info in the forum here that I've been reading through but I (definitely!) could use some advice. I've basically taken the Energy Advisor report (and yes, I know it is likely very overstated for energy usage) and designed a (multiple) rooftop/garagetop PV array using Skelion for modeling solar. This is of course, going to be Net Metered.

The electrical service entrance is 400A going to the detached garage, but will split into 3. One 200A panel for the Main Suite, 100A for the Secondary Suite, and 100A for the Garage. (Leviton Smart Panel doesn't have "in-between" ampacity sizes, unfortunately.) One important note here is that the 200A and 100A panels will be in house in their respective suites/areas and the 100A would be in the detached garage.

In the longer run, I'd like to be able to battery back everything (more or less) with Smart Breakers installed in circuits for large loads that I'd want to shed: heat pump washer/dryer, combo-oven, EV charger, that sort of thing. The house is all electric with 2 x heat pumps (one for DHW and radiant heat, one dedicated for AC although technically, it can heat as well). Despite this, my suspicion is that I would rarely if ever actually hit over 12KW for any length of time in regular use, less so during an "outage" with loads shed. Another thing to note, I haven't quite figured out yet which panel I should hang my 2 x Heat Pumps since they are right by the garage. The options are of course, placing another panel in the garage that would break out X Amps for heat pumps, before continuing to the main suite panel in the house; or putting them on the garage panel (along with EV). I can probably get away with 4.8KW charging for the EV (actually I could probably get away with L1 charging!) because we don't travel all that much (and an EV is part of future plans...don't have one at the moment).

In any case, would you all recommend 1 x EG4 18K on the 200A Main Suite, and putting the 100A Secondary Suite and 100A Garage Panel on the 2nd (and independent, non-slaved) 18KPV. If I do this and have the heat pumps on the 100A garage panel, am I able to have the 18KPV's share battery banks? Or must I wire batteries completely independently to each 18KPV?

Or do I can run the full 400A service into 2x18KPV in parallel (or should it be 3 since there's some slight derating necessary?), then output 200A to main suite, 100A to secondary suite, and 100A to the garage? Would I basically follow Page 35 of the EG4 18kPV manual but with larger fuses for the input and output combiners? I'm guessing using 400A capable combiners, transfers etc will be more expensive?

I'm also open to "better ways" of setting this all up. The house isn't large (actually slightly smaller than Vancouver standard lot, 33'x110') but it is getting very "packed" so in some sense, less is more. BTW, I also can't place the Inverter and Batteries outside (like I wanted to) as I have a number of "site hardships" which include a pole mounted transformer (no panels within 6m cylinder) which necessitated shifting my garage over Eastward...meaning inverter/batteries would get a lot of direct sun (albeit Vancouver sun vs. Texas heat) during summer months. So, I'll have to stuff them inside the garage as well...sigh.

Thanks in advance!

 

[NovicePV]

I forgot to add...I think the 2x18KPV Parallel Diagram on Page 35 (below) is confusing me just a little bit as the combiners have 60A fuses to/from each Inverter. Doesn't that effectively limit the load output to 120A? I understand that each 18KPV can supply 50A when off-grid (maybe that's why it's 60A breaker) but should each 18kPV be able to backfeed (I believe that's the correct terminology) the full 200A when on-grid? Isn't this artificially limiting each unit? In the case of a 200A Main Service, wouldn't you want to have 100A per inverter input and 100A ouput?

Then, in a 400A service, 2x 18kPV parallel situation, wouldn't you want to have 200A/inverter in the input/output combiner panel? Then, one would split into whatever panels one wants, after the "optional generator trasnfer switch"?

Thanks again!

 

[NovicePV]

I forgot to add...I think the 2x18KPV Parallel Diagram on Page 35 (below) is confusing me just a little bit as the combiners have 60A fuses to/from each Inverter. Doesn't that effectively limit the load output to 120A? I understand that each 18KPV can supply 50A when off-grid (maybe that's why it's 60A breaker) but should each 18kPV be able to backfeed (I believe that's the correct terminology) the full 200A when on-grid? Isn't this artificially limiting each unit? In the case of a 200A Main Service, wouldn't you want to have 100A per inverter input and 100A ouput?

Then, in a 400A service, 2x 18kPV parallel situation, wouldn't you want to have 200A/inverter in the input/output combiner panel? Then, one would split into whatever panels one wants, after the "optional generator trasnfer switch"?

Thanks again!

View attachment 186163

Bump! @EG4_Jarrett Would you have any idea about this offhand? I also emailed EG4 support using the contact form...

Thanks!

 

[Shimmy]

Generally centralizing is going to have better resource utilization; the caveat is if you have drastically different expectations for each sub-panel.

Personally I hate the smart breakers. I would prefer higher level load shed, like a smart washer/dryer where you schedule loads rather than shed them.

 

[NovicePV]

Hrm...so parallel 18KPV system with a shared pool of battery power, at least until I start loading up more than 5X PowerPro's which would be quite a while down the line I would think? I think what I can't quite get my head around (some missing "link" somewhere) is if I run parallel where I would "split" the 400A service. Would I feed the 400A service into 200A + 200A combiner which then goes to each inverter, then at the output combine back into 400A before then splitting it into 200A, 100A, then 100A? From what I've been reading here on the forums, this is generally not preferred as the 400A rated "accessories" are far more costly than the 200A rated stuff.

As for expected loads, the secondary suite would be rather tiny. The largest would be a standard washer/dryer, and electric stove, and refrigerator--the only item I would want to actually "backup." The "main suite" would be the energy "hog" relatively speaking. 2 x Heat Pumps w/electric element boost/backup DHW heater so that I can run the HP in it's efficiency range, 1 X Heat Pump Washer/Dryer, 2 x combo-ovens, Induction Stove (that's a big big hog potentially), not to mention various computer/network gear. Again, the only things I'd really like to back up here are the 2 x Heat Pumps, the refrigerator, computer/network gear and maybe a few more "useful" LED lights here and there.

I thought about using an emergency load panel but because both my suites have to have their own panels, I'd have to split out into 2 separate emergency panels--not a deal breaker, but certainly more than I anticiapted and somewhat overkill as literally, only the refrigerator on the secondary suite needs to be backed up. It also doesn't allow for as much flexibility as breaker level control.

As for the smart breakers...well, the only choice we have here are Leviton smart breakers (which are rather pricey actually) or something like Shelly's. SPAN aren't certified for use here in Canada anyways...neither are things like oh...EcoFlow's Smart Home Panel (1 or 2) and pretty much any other panels you can name. I take it with ~33M people, Canada is a "tiny market" compared to the USA. In all honesty though, our power doesn't go out very often. A few minutes if even that, per year. BC Hydro has a surprisingly robust grid and their crews are pretty fast at repairing things.

I suspect at the end of the day, I'm drastically overthinking things and I should probably just start off backing up the 200A main suite panel if I want to save some money upfront. I can then "expand outward" from there down the line when I have additional $ to throw at the project. As I saw from many others commenting on their own houses that they rarely, if ever, have >=10KW instantaneous power draws.

All that said, I'd still like to figure out why the parallel diagram above uses 60A instead of 100A breakers as that seems to be artificially limiting input/output while on grid.

Thanks!

 

[PeteYates]

Hrm...so parallel 18KPV system with a shared pool of battery power, at least until I start loading up more than 5X PowerPro's which would be quite a while down the line I would think? I think what I can't quite get my head around (some missing "link" somewhere) is if I run parallel where I would "split" the 400A service. Would I feed the 400A service into 200A + 200A combiner which then goes to each inverter, then at the output combine back into 400A before then splitting it into 200A, 100A, then 100A? From what I've been reading here on the forums, this is generally not preferred as the 400A rated "accessories" are far more costly than the 200A rated stuff.

As for expected loads, the secondary suite would be rather tiny. The largest would be a standard washer/dryer, and electric stove, and refrigerator--the only item I would want to actually "backup." The "main suite" would be the energy "hog" relatively speaking. 2 x Heat Pumps w/electric element boost/backup DHW heater so that I can run the HP in it's efficiency range, 1 X Heat Pump Washer/Dryer, 2 x combo-ovens, Induction Stove (that's a big big hog potentially), not to mention various computer/network gear. Again, the only things I'd really like to back up here are the 2 x Heat Pumps, the refrigerator, computer/network gear and maybe a few more "useful" LED lights here and there.

I thought about using an emergency load panel but because both my suites have to have their own panels, I'd have to split out into 2 separate emergency panels--not a deal breaker, but certainly more than I anticiapted and somewhat overkill as literally, only the refrigerator on the secondary suite needs to be backed up. It also doesn't allow for as much flexibility as breaker level control.

As for the smart breakers...well, the only choice we have here are Leviton smart breakers (which are rather pricey actually) or something like Shelly's. SPAN aren't certified for use here in Canada anyways...neither are things like oh...EcoFlow's Smart Home Panel (1 or 2) and pretty much any other panels you can name. I take it with ~33M people, Canada is a "tiny market" compared to the USA. In all honesty though, our power doesn't go out very often. A few minutes if even that, per year. BC Hydro has a surprisingly robust grid and their crews are pretty fast at repairing things.

I suspect at the end of the day, I'm drastically overthinking things and I should probably just start off backing up the 200A main suite panel if I want to save some money upfront. I can then "expand outward" from there down the line when I have additional $ to throw at the project. As I saw from many others commenting on their own houses that they rarely, if ever, have >=10KW instantaneous power draws.

All that said, I'd still like to figure out why the parallel diagram above uses 60A instead of 100A breakers as that seems to be artificially limiting input/output while on grid.

Thanks!

I am trying to navigate similar design issues with a 400A main and 2 200A branches with the second panel remote from main. I have 3 A/C units hanging off each branch and during summers in AZ, all 6 could be turning on simulateously.SS had advised they were working on the 'design' for this scenario and I guess page 35 is their first pass.

Sol-Ark have their version of this design (attached for comparison). They use a combiner panel and shared battery design.

Like you i am considering just doing the install on the branch that has the main load during peak hours (my predominant ROI is peak shaving) and then expanding to the second branch at a later date. However, I am concerned about the upgrade path and hence have not finished my due diligence.

All advice welcome

 

[NovicePV]

I am trying to navigate similar design issues with a 400A main and 2 200A branches with the second panel remote from main. I have 3 A/C units hanging off each branch and during summers in AZ, all 6 could be turning on simulateously.SS had advised they were working on the 'design' for this scenario and I guess page 35 is their first pass.

Sol-Ark have their version of this design (attached for comparison). They use a combiner panel and shared battery design.

Like you i am considering just doing the install on the branch that has the main load during peak hours (my predominant ROI is peak shaving) and then expanding to the second branch at a later date. However, I am concerned about the upgrade path and hence have not finished my due diligence.

All advice welcome

WHOA! 6xA/C units...but I guess you're in AZ after all. And here I am worried about having to place my heat pumps on the "sunny west side" and the potential reduced efficiency.

The shared battery shouldn't be an issue with the paralleled hybrid Inverters because presumably, communications happen between the batteries and the 18KPV AND the 2 x 18KPV. What I'm not sure about is whether one can share banks if the 18KPV's are both in "Master" (independent) modes, with each outputting to their separate 200A panels. My suspicion based on everything I've read is "no."

The Sol-Ark diagram you attached is exactly what I think EG4/Luxpower/Signature Solar is going to eventually recommend. Split the 400A from main into 2x200A breakers, parallel the inverters, re-combine the output and then split again into 200A panels. This would allow for 100A (well, let's say 90A since it's probably a good idea to de-rate slightly) maximum output in grid-out scenario with the flexibility of "whichever 200A branch" drawing what it needs of the available max. So, a branch could have 10A load and the other branch could suck up 80A and it would "still work."

I would hazard a guess that one could chose to not use the output combiner and instead feed the outputs to their own 200A branch panels. The downside to that of course, is you lose the inherent flexibility of the paralleled and shared 90A max output of the 2 x 18KPV being utilized by whichever branch needs it, and instead restrict each branch panel to 50A.

@EG4_Jarrett @SignatureSolarJames @Luxpower_Gilbert Any comments/thoughts on this? I highly suspect as we all tend to move into a more "electrified future," these 400A questions are going to get far more common!

Thanks!

 

[PeteYates]

response from sol ark

2. If the inverters are paralleled together and communicating, the emergency stop button connecting to the master will also signal the other connected inverters to shutdown as well. If inverters are not paralleled, then each inverter would need its own emergency stop button.

3. For PV input, strings can run directly to each inverter. For the battery, there would need to be a combiner so that the inverters can share the battery.

4. A lot of installs use simple polaris terminals or something similar for systems that only have two inverters to combine each AC line. If you were to use a combiner panel it would need to be rated for the total pass-through that you need. For 400A of pass-through, then you would need a 400A combiner to support both 200A panels.

5. The breakers would need to be 200A for the full 200A pass-through for each inverter.

 

[EG4_Jarrett]

Bump! @EG4_Jarrett Would you have any idea about this offhand? I also emailed EG4 support using the contact form...

Thanks!

Just so I have mentioned it, our email inbox is absolutely crazy right now, so if you are still waiting on a response, bear with us please. Even I am in there answering emails, so we aren't ignoring you, we just havent made it to your email yet. I am also working on getting some automation put in place to let people know that we have received their request and are working on getting a response out to you.

Bump! @EG4_Jarrett Would you have any idea about this offhand? I also emailed EG4 support using the contact form...

Thanks!

So, just to clarify, these are not the only ways to install the inverters and are just some of the ways that you can do it. It can be used as an instructional guide or as a guideline. In the example you posted, the PV interactive fused disconnect stated that it should be >=120a. This example shows it at its lowest value, but that fuse size can be increased to cover what you need. The breaker size can also be increased at that point as well. So yes, in this example it does limit the amount of power that can used in the bypass, but that's because it's limited to the size of the fuse. You also need to make sure that you are sizing your wire and the BUS on the panel accordingly as well. Let me know if this answers your question. There were a lot of questions here and I want to make sure that I get to all of them.

As far as the 400a service, I would need to get more information on this. In theory, I would think it would work, but I have not personally done that myself. That's my only hang-up on giving you an answer on this, so I want to make sure that I have the right information first. My personal philosophy of answering these tech questions and scenarios is to make sure I have either done it myself first, or get firsthand information from someone that has.

And yes, I 100% agree with you. With how many of these inverters we have been selling, a lot more people will want to know this. So, I will find out and get back to you about the 400a service installation ASAP.

 

[PeteYates]

WHOA! 6xA/C units...but I guess you're in AZ after all. And here I am worried about having to place my heat pumps on the "sunny west side" and the potential reduced efficiency.

The shared battery shouldn't be an issue with the paralleled hybrid Inverters because presumably, communications happen between the batteries and the 18KPV AND the 2 x 18KPV. What I'm not sure about is whether one can share banks if the 18KPV's are both in "Master" (independent) modes, with each outputting to their separate 200A panels. My suspicion based on everything I've read is "no."

The Sol-Ark diagram you attached is exactly what I think EG4/Luxpower/Signature Solar is going to eventually recommend. Split the 400A from main into 2x200A breakers, parallel the inverters, re-combine the output and then split again into 200A panels. This would allow for 100A (well, let's say 90A since it's probably a good idea to de-rate slightly) maximum output in grid-out scenario with the flexibility of "whichever 200A branch" drawing what it needs of the available max. So, a branch could have 10A load and the other branch could suck up 80A and it would "still work."

I would hazard a guess that one could chose to not use the output combiner and instead feed the outputs to their own 200A branch panels. The downside to that of course, is you lose the inherent flexibility of the paralleled and shared 90A max output of the 2 x 18KPV being utilized by whichever branch needs it, and instead restrict each branch panel to 50A.

@EG4_Jarrett @SignatureSolarJames @Luxpower_Gilbert Any comments/thoughts on this? I highly suspect as we all tend to move into a more "electrified future," these 400A questions are going to get far more common!

Thanks!

I am not looking to go off grid....grid tied with only about 50% of needs generated via PV. So inverter is a distribution hub.
Using batteries to reduce peak consumption by approx 7kw in every hour of peak rate.

Failure modes of inverter is key...i.e. in event of trip does the unit continue to pass mains power to the house (can't have inverter disconnect grid when I am away from home in the summer). Sol-Ark defaults to grid connect in failure....not had response from SS yet.

 

[NovicePV]

Just so I have mentioned it, our email inbox is absolutely crazy right now, so if you are still waiting on a response, bear with us please. Even I am in there answering emails, so we aren't ignoring you, we just havent made it to your email yet. I am also working on getting some automation put in place to let people know that we have received their request and are working on getting a response out to you.


So, just to clarify, these are not the only ways to install the inverters and are just some of the ways that you can do it. It can be used as an instructional guide or as a guideline. In the example you posted, the PV interactive fused disconnect stated that it should be >=120a. This example shows it at its lowest value, but that fuse size can be increased to cover what you need. The breaker size can also be increased at that point as well. So yes, in this example it does limit the amount of power that can used in the bypass, but that's because it's limited to the size of the fuse. You also need to make sure that you are sizing your wire and the BUS on the panel accordingly as well. Let me know if this answers your question. There were a lot of questions here and I want to make sure that I get to all of them.

As far as the 400a service, I would need to get more information on this. In theory, I would think it would work, but I have not personally done that myself. That's my only hang-up on giving you an answer on this, so I want to make sure that I have the right information first. My personal philosophy of answering these tech questions and scenarios is to make sure I have either done it myself first, or get firsthand information from someone that has.

And yes, I 100% agree with you. With how many of these inverters we have been selling, a lot more people will want to know this. So, I will find out and get back to you about the 400a service installation ASAP.

Thanks so much @EG4_Jarrett...and my apologies for my seeming impatience! I did figure that email volume was the issue which is why I posted here in hopes the larger community would have ideas/solutions too! One small suggestion would be to have a confirmation email auto-sent after an online (web) inquiry is submitted. I've had a few cases with other companies where the online form showed "thanks for the message" but the company never actually got my email!

Thanks so much for the information you stated. As my title states, I'm up in Vancouver BC and there is a BIG "build green" push here. 2035 everything has to be Net Zero ready. Thing is installers only know "Enphase and Tesla" so there definitely are opportunities to expand up here. Feel free to contact me directly if you think it more appropriate although I think it'd be nice to have the info on my project made public (at least eventually) so anyone/everyone can benefit.

Thanks again!

 

[EG4_Jarrett]

Thanks so much @EG4_Jarrett...and my apologies for my seeming impatience! I did figure that email volume was the issue which is why I posted here in hopes the larger community would have ideas/solutions too! One small suggestion would be to have a confirmation email auto-sent after an online (web) inquiry is submitted. I've had a few cases with other companies where the online form showed "thanks for the message" but the company never actually got my email!

It's funny you mention that! I am working on getting email confirmation automation as we speak. Not sure on the specifics, but it's new to us and we want to make sure that we get some sort of engagement out there. Typically, our team is really good about getting back to emails, but with the increased volume, I want to make sure that our customer base is aware that we did get the email and we will get back to you.

Feel free to contact me directly if you think it more appropriate although I think it'd be nice to have the info on my project made public (at least eventually) so anyone/everyone can benefit.

I definitely want to keep information that is shared out here in the open. Typically, the only time I take things to direct message, is if I am DM'd by someone which is a regular occurrence, or if it requires sensitive information (ie. customer email/address/phone number/serial numbers/etc). Aside from that, I try to speak on everything publicly.

 

[NovicePV]

response from sol ark

2. If the inverters are paralleled together and communicating, the emergency stop button connecting to the master will also signal the other connected inverters to shutdown as well. If inverters are not paralleled, then each inverter would need its own emergency stop button.

3. For PV input, strings can run directly to each inverter. For the battery, there would need to be a combiner so that the inverters can share the battery.

4. A lot of installs use simple polaris terminals or something similar for systems that only have two inverters to combine each AC line. If you were to use a combiner panel it would need to be rated for the total pass-through that you need. For 400A of pass-through, then you would need a 400A combiner to support both 200A panels.

5. The breakers would need to be 200A for the full 200A pass-through for each inverter.

Interesting responses on the Sol Ark side.

Re: #2 - I'd expect this would be true of every paralleled system on the market given the inverters are interconnected/communicate with each other.

Re: #3 - It would appear this is true of the LuxPower/EG4 units as well, that is, PV strings can be added to either inverter. As for the batteries, based on the diagrams/info here on DIYSolarForum "Paralleling the EG4 PowerPro Wall battery" it would appear that EG4's own solution of 18KPV + their PowerPros will not require any "external combiner/bus bar" up to 5X batteries. Presumably, the closed loop comms would be hooked up to the Master Inverter which will then communicate appropriate info to the Slave(s). For scenarios where more than 5 batteries are utilized, you could then split up banks between the 2 inverters and have comms from each bank (up to 5 each) directly connected to each inverter.

Re: #4 - I have no idea if this would be code-compliant...but my guess is that local to me, it would not be compliant. I'm almost certain a breaker'd combiner box would be required as opposed to a "2-in, 2-out" polaris multi-tap terminal, joining up the output of the inverters then splitting them to 2 x 200A branch boxes.

Lastly, as you brought up in the other reply...failure mode is a rather important aspect I didn't actually think about either! Thanks for flagging that! I wonder how the EG4 18KPV would "react?" Ideal scenario is exactly as you say: continue to passthrough grid power in event of failure (within reason/depending on failed component of course.

@EG4_Jarrett Thanks for the info you provided regarding p.35's parallel diagram. What you said about the breakers limiting grid backfeed makes perfect sense and confirms my "sanity check." As I read online/through these forums, it seems many with 400A immediately split it into 2 x 200A panels with feeder taps on each 200A branch to 18KPV's as opposed to dealing with the full 400A being fed into 18KPV's. It also seems to me, that one of the motivations for doing so is due to the increased cost of 400A-rated equipment. However, a possible downside (depending on everyone's individual panel locations/setups) seems to be less flexibility after the fact.

In my scenario, having 2x18KPV's (to start) hanging off the 400A service, and recombining it, allows all panels to be battery/solar "backed." I can choose to hang my heat pumps off my garage panel (easier wiring), and still ensure that "whatever" in the secondary suite (refrigerator really) is backed up, along with my main suite loads. And if "something" on "whatever panel" needs the headroom for a "spike in power," it can have it, only limited by the xyz number of inverters I have in parallel. Future expansion is arguably easier to do (if combiners with sufficient inputs/outputs are used). And as for battery expansion, I guess for the banks to be connected to all 3 inverters, you'd have to bus bar them, even when using EG4's PowerPros.

Thanks!

 

[NovicePV]

OK...I made a quick block diagram of how my 400A setup "might" work if I wanted to ensure the full 400A being: a) backfed and b) backed up in an outage.



I think there's probably a way to do this with the 400A first being broken out into 2x200A services, then feeding through to the EG4 but one would still have to recombine at the output in order to backup "all panels" which doesn't save that much as 400A rated equipment would still be needed.

Thanks!

 

[Shimmy]

OK...I made a quick block diagram of how my 400A setup "might" work if I wanted to ensure the full 400A being: a) backfed and b) backed up in an outage.

I think there's probably a way to do this with the 400A first being broken out into 2x200A services, then feeding through to the EG4 but one would still have to recombine at the output in order to backup "all panels" which doesn't save that much as 400A rated equipment would still be needed.

Thanks!

Nix the generator combiner; just run it to a single EG4. Doing it as drawn will parallel two paths that shouldn't be paralleled.

For what you are doing, you would likely be better off with a single 400A external transfer switch and keep the EG4 input/output feeds at 80 or 100A. 400A panels are expensive compared to 200A with 100A branch breakers.

 

[NovicePV]

Nix the generator combiner; just run it to a single EG4. Doing it as drawn will parallel two paths that shouldn't be paralleled.

For what you are doing, you would likely be better off with a single 400A external transfer switch and keep the EG4 input/output feeds at 80 or 100A. 400A panels are expensive compared to 200A with 100A branch breakers.

Will do re: the generator.

Would the EG4's still be wired as master/slave? Or would I just have each as a master serving 200A each? I ask because I'm fairly certain in the separated config, they can't share battery banks?

Thanks!

 

[NovicePV]

Hrm, quick question for the experts here/those of you who know far more than I, if the inverter can output 50A, what happens if you have 18kW of solar on an "ideal/lossless" sunny day and one is net metering? Is it having to shed some 25A of power? i.e. there is a "not-insubstantial-portion" that is not being fed back into the grid. Is that right?

 

[PeteYates]

Will do re: the generator.

Would the EG4's still be wired as master/slave? Or would I just have each as a master serving 200A each? I ask because I'm fairly certain in the separated config, they can't share battery banks?

Thanks!

I have considered both scenario's and for my situation where the second sub panel and second array are distant from the first then 2 independent systems seems more logical. It duplicates emergency shut off's etc but keeps each system dedicated to the branch its supporting. I will have to see if i get push back from utility provider.

In the master/slave/combiner option, according to SolArk then the 2 provide load balancing to the full 400A and the batteries must be shared.

 

[ElectricIslander]

I forgot to add...I think the 2x18KPV Parallel Diagram on Page 35 (below) is confusing me just a little bit as the combiners have 60A fuses to/from each Inverter. Doesn't that effectively limit the load output to 120A? I understand that each 18KPV can supply 50A when off-grid (maybe that's why it's 60A breaker) but should each 18kPV be able to backfeed (I believe that's the correct terminology) the full 200A when on-grid? Isn't this artificially limiting each unit? In the case of a 200A Main Service, wouldn't you want to have 100A per inverter input and 100A ouput?

Then, in a 400A service, 2x 18kPV parallel situation, wouldn't you want to have 200A/inverter in the input/output combiner panel? Then, one would split into whatever panels one wants, after the "optional generator trasnfer switch"?

Thanks again!

View attachment 186163

Hi - I'm in Vancouver too, but we are off grid on a little island.

How are you making these wiring diagrams? And what did you find most useful about Skelion? I've tried it with Sketchup 2017 but haven't gotten very far yet. We are planning about 7kW of panels and an XWPro / Element battery system.

 

[NovicePV]

Hi - I'm in Vancouver too, but we are off grid on a little island.

How are you making these wiring diagrams? And what did you find most useful about Skelion? I've tried it with Sketchup 2017 but haven't gotten very far yet. We are planning about 7kW of panels and an XWPro / Element battery system.

Wiring diagrams I just quickly made in PPT as they don't need anything more complex.

As for Skelion, it's kind of necessary in order to (somewhat) accurately predict actual solar power generation. If you don't have space limitations then I suppose you don't need Skelion since you can just add panels as needed.

Do you know how much energy your 7kW will actually generate over the course of a year?