4.5kW SolarEdge/LG System coming soon to San Diego

[sensij]

The vendor gave me these expected production numbers:
My understanding is that the difference is based on the nameplate difference and the 1% less linear warrantied performance of the LG280s

What? Are you talking LG300NIC-B3's? I thought this installer was using LG300NIC-G3's. The G3 has basically the same performance as the 280's. I don't know why their model would show much difference between them per nameplate watt.

Edit: BTW, nice negotiating. That looks like a great price for your system.

[subdriver97]

What? Are you talking LG300NIC-B3's? I thought this installer was using LG300NIC-G3's. The G3 has basically the same performance as the 280's. I don't know why their model would show much difference between them per nameplate watt.

Edit: BTW, nice negotiating. That looks like a great price for your system.

I think you're right about the vendor using LG300NIC-G3's. Although, the written proposals haven't specified the exact model of LG300 & LG280, but I will ask for specifics. Based on the production numbers the only way I can come up with nearly the same production difference is to account for the nameplate difference and 71kWh for the 1% efficiency difference between the LG300NIC-B3s and the LG280SIC-B3s...

Do you know the difference between the Mono X Neon A3s and B3s?

[sensij]

I think you're right about the vendor using LG300NIC-G3's. Although, the written proposals haven't specified the exact model of LG300 & LG280, but I will ask for specifics. Based on the production numbers the only way I can come up with nearly the same production difference is to account for the nameplate difference and 71kWh for the 1% efficiency difference between the LG300NIC-B3s and the LG280SIC-B3s...

Do you know the difference between the Mono X Neon A3s and B3s?

I'm unaware of a difference, the data sheets between the LG270S1C-A3 and LG270S1C-B3 are identical. I think the S1C-A3 series maxed out at 270 W, in that generation I think to get more power you had to go to the N1C-G3's. In the S1C-B3 series, 280 W is the max, so it might just represent some incremental improvement in their manufacturing process that let them bring to market a slightly more efficient panel.

edit... sorry, misread your post. On the Mono X Neon (N1C series), the only difference between A3 and B3 that I see on the data sheet is slightly improved low light / shaded performance for the B3, which has < 2% efficiency loss dropping from 1000 W/m2 to 200 W/m2 vs < 3.5% for the A3.

[subdriver97]

I'm unaware of a difference, the data sheets between the LG270S1C-A3 and LG270S1C-B3 are identical. I think the S1C-A3 series maxed out at 270 W, in that generation I think to get more power you had to go to the N1C-G3's. In the S1C-B3 series, 280 W is the max, so it might just represent some incremental improvement in their manufacturing process that let them bring to market a slightly more efficient panel.

edit... sorry, misread your post. On the Mono X Neon (N1C series), the only difference between A3 and B3 that I see on the data sheet is slightly improved low light / shaded performance for the B3, which has <2% efficiency loss dropping from 1000 W/m2 to 200 W/m2 vs < 3.5% for the A3.

I noticed that the Mono X Neon series is advertised as double-sided. Does anyone know if the non-Neon panels are single sided?


I was wondering if anyone knows how the differences in nameplate kW come about with panels in the same series. I have no idea, but I was guessing that when LG gets a batch of panel material they sort them into batches by quality that yield different nameplate kW???

[subdriver97]

I think you're right about the vendor using LG300NIC-G3's. Although, the written proposals haven't specified the exact model of LG300 & LG280, but I will ask for specifics. Based on the production numbers the only way I can come up with nearly the same production difference is to account for the nameplate difference and 71kWh for the 1% efficiency difference between the LG300NIC-B3s and the LG280SIC-B3s...

Do you know the difference between the Mono X Neon A3s and B3s?

I must be completely blind. I just noticed that the model numbers are clearly listed on the written quotes. The quotes are written for LG300N1C-G3 and LG280N1C-B3. If that's the case then the only production difference would be based on the difference in system nameplate kW... which would greatly justify almost 5% decrease in price.

I've written an email to the vendor to verify that these exact model numbers were used in the modeling, I suspect LG300N1C-A3 or B3 were used...

[subdriver97]

I'm unaware of a difference, the data sheets between the LG270S1C-A3 and LG270S1C-B3 are identical. I think the S1C-A3 series maxed out at 270 W, in that generation I think to get more power you had to go to the N1C-G3's. In the S1C-B3 series, 280 W is the max, so it might just represent some incremental improvement in their manufacturing process that let them bring to market a slightly more efficient panel.

edit... sorry, misread your post. On the Mono X Neon (N1C series), the only difference between A3 and B3 that I see on the data sheet is slightly improved low light / shaded performance for the B3, which has < 2% efficiency loss dropping from 1000 W/m2 to 200 W/m2 vs < 3.5% for the A3.

I got the following from my vendor regarding the differences between A3, B3, & G3:

G3: Old designation and discontinued model. Primarily used to denote the changed frame profile thickness from the G2 model.
A3: Old designation and discontinued model. Used to identify a different manufacturer of the DC junction box on the back.
B3: Current designation/model. This latest designation tracks the larger cell size. It's the same overall footprint, but with the larger cells it has less visible white backsheet. It's noticeably different from the A3 when side by side.

[thejq]

Thejq, Since you mentioned the main breaker panel. I was wondering what size breaker do you have on your SE6000? I'm wondering if the breaker size would be different for SE5000 vs SE6000.

I have 30A breakers. Theoretically for SE5000, 25A would be enough. Also FYI, the panels I have is LG300N1C-B3.

[thejq]

subdriver97 and theJQ,

First, thanks for forwarding over your installer information. I called them and received a very competitive quote.

I plan to talk with them tomorrow and when I do I am going to inquire about their choice of hardware for roof mounting / flashing. Did you by chance ask them? If so, would you please share?

Have heard great things about a product called Quick-Mount PV which is supposedly the best in the industry. I'm hoping that they use this product.

Hi Louie

In my installation, they used QuickMount standoffs, and IronRidge rails. Both are top notch products. The installation took a little more than 4 days.

[subdriver97]

Will update as they come...

My vendor came by and performed the site survey today (measure the roof and inspect the service panel). The service panel inspection revealed the following:

IMG_4848A.JPGIMG_4847-2.JPG

Bottom Line Up Front: Is an End-Fed Breaker required for a pv system in San Diego?

The vendor project manager told me: The Service Panel paperwork indicates that the panel is 125A degraded to 100A. Therefore, the 50A Oven breaker can be replaced with two breakers, one for the oven and 25A for the solar system.

I think: This sounds correct because if the solar is at +25A and +100A is coming through the main breaker the most that can be on the bus is 125A, which is what the panel is rated at.

Google Found: A nice write-up on NEC regulations regarding Center-Fed Load Centers http://www.nmsu.edu/~tdi/pdf-resourc...Aug%202014.pdf Here's a summary of the article:
"Center-fed panelboards or load centers are found throughout the country in existing and new electrical installations. There are several ways that PV systems may be connected to the center-fed panel boards and in all cases they can be replaced with an end-fed panelboard for complete compliance with existing codes. The 2014 NEC will allow center-fed panelboards to be used under engineering supervision and these requirements may be applied to earlier codes using the alternate methods and materials allowances."

Question: While the vendor's solution jives with 2014 NEC... how do I find out what regulations have been adopted in the San Diego jurisdiction? Does a PV install absolutely require an End-Fed Breaker? Or does a degraded main breaker all for a PV breaker the size of the degradation? Can someone speak from experience and/or direct me to the applicable regulation?

*** Apologies, the are rotated correctly on my machine but after they get uploaded to the website they keep showing up on their side. If anyone knows how to fix this please PM me.

[subdriver97]

My vendor came by and performed the site survey today (measure the roof and inspect the service panel). The service panel inspection revealed the following:

[ATTACH=CONFIG]5299[/ATTACH][ATTACH=CONFIG]5300[/ATTACH]

Bottom Line Up Front: Is an End-Fed Breaker required for a pv system in San Diego?

The vendor project manager told me: The Service Panel paperwork indicates that the panel is 125A degraded to 100A. Therefore, the 50A Oven breaker can be replaced with two breakers, one for the oven and 25A for the solar system.

I think: This sounds correct because if the solar is at +25A and +100A is coming through the main breaker the most that can be on the bus is 125A, which is what the panel is rated at.

Google Found: A nice write-up on NEC regulations regarding Center-Fed Load Centers http://www.nmsu.edu/~tdi/pdf-resourc...Aug%202014.pdf Here's a summary of the article:
"Center-fed panelboards or load centers are found throughout the country in existing and new electrical installations. There are several ways that PV systems may be connected to the center-fed panel boards and in all cases they can be replaced with an end-fed panelboard for complete compliance with existing codes. The 2014 NEC will allow center-fed panelboards to be used under engineering supervision and these requirements may be applied to earlier codes using the alternate methods and materials allowances."

Question: While the vendor's solution jives with 2014 NEC... how do I find out what regulations have been adopted in the San Diego jurisdiction? Does a PV install absolutely require an End-Fed Breaker? Or does a degraded main breaker all for a PV breaker the size of the degradation? Can someone speak from experience and/or direct me to the applicable regulation?

*** Apologies, the are rotated correctly on my machine but after they get uploaded to the website they keep showing up on their side. If anyone knows how to fix this please PM me.

Google Also Found:
The above solution jives with section 3.2.3 Para 8 of the California Energy Commissions Guide to PV System Design and Installation http://www.energy.ca.gov/reports/200...500-01-020.PDF

[sensij]

That report you found is a little dated, so I would be careful about trusting it completely. I will reply in parts to your post, and perhaps others will confirm or fill in some gaps.

For starters, San Diego follows the California Building Standard Code. The section that is applicable to electrical is defined by California Code of Regulations Title 24 part 3 (better link here). The 2013 cycle of code was based heavily on the 2011 NEC, and it is likely that the next cycle in 2016 will follow the 2014 NEC. There was a mid-cycle revision to the electrical code that will take effect July 1 next year relating to plug-in chargers for EV's, but nothing that directly relates to your question.

Section 690 specifically covers PV systems, although other sections still apply if required.

The fact that CA is still 2011 and has not yet adopted 2014 makes life a little easier for PV installers in some ways, but not in others. The 2014 code had several changes that will come into play when CA eventually adopts it, discussed in some detail here, which might be worth knowing in the event you expect to make changes to your installed system in a couple years that may require complying to the new standard to pass inspection. FWIW, SolarEdge can be more easily made to be NEC 2014 compliant than some other commonly installed inverters.

[thejq]

If I understand it correctly, the vendor is suggesting not to upgrade the panel and you like to know if it's ok. Technically, I'm sure it's ok, if your vendor says so. Because if it doesn't pass city inspection, they don't get paid. But there're practical considerations too. If you don't upgrade the panel now, you're maxing out the panel capacity, so you won't be able to add anything later on, eg. a pool pump, heat pump, EV charger or more solar panels beyond 5KW. Also financially, if you do it now, IRS will pay 30% of the cost. Not suggesting either way, but I just to give you some more POV.

[sensij]

There is a great write-up on PV breaker position here, as it was defined by 2011 code. Although the conclusion was that center-fed is not OK, that is only for the case of the main breaker and busbar having the same rating. The key section of code referred to is 705.12(D)(7), which starts with this:

Unless the panel board is rated not less than the sum of the ampere ratings of all overcurrent devices supplying it, a connection in a panelboard shall be positioned at the opposite (load) end from the input feeder location or main circuit location.

In other words, for panels rated at or above the ampere rating of all overcurrent devices supplying it, the opposite end positioning is not explicitly required by this section of code. Since your panel is rated 125 A, and the sum of the overcurrent devices supplying it are 100 A and 25 A, you meet the first requirement that would allow you to consider a non-opposite end location.

I would question whether a 25 A standard breaker is suitable for the SE5000A, since that inverter can continuously output 21 A @ 240 V and 125% of that is 26.25 A. The 1.25 breaker size requirement is from 215.3. For that matter, the 30 A breaker on the SE6000A appears undersized (25 A x 1.25 = 31.25 A), so I don't know why that passed for thejq. Although 215.3 includes an exception for components listed for use at 100% of rating, as far as I know, the only commercially available breakers that are rated that way are 125A or greater. There are also additional wiring requirements that would need to be met to use them properly.

Edit: Further support for questioning the use of a 25 A breaker with the SE5000A can be found by examining other permit applications. For example, 3rd party software is used by at least one national installer to generate their permit docs. Example output of that software uses the SE5000A in its design, and calls out a 30 A breaker. You might argue that if you do not put enough panels on for the inverter to reach its rated output a smaller breaker could be justified, but 690.8(A)(3) explicitly says that the inverter's continuous output rating is to be used.

So, before chasing down whether center-fed is OK by using Article 220 to determine if the load distribution on the busbar is compliant (since the sum of all the breakers (excluding main feed) would exceed the 125 Amp busbar rating), if it was me, I would be asking questions about the 25 A OCPD choice. If more than 25 A is required, the 705.12(D)(7) test fails (both the 2011 and the 2014 version) and the PV breaker must be opposite the main feed, and center fed would not be allowed.

On the other hand, you can choose not to question it, and let the installer bear the risk of the permit not being approved and / or inspection not passing. You would only need to prepare yourself for eventual installation delays and the panel upgrade cost, should the AHJ agree with the interpretation I've posted. Based on what thejq reported, perhaps this installer has a relationship with the AHJ that would make any discussion here irrelevant.

Here is another thread discussing this very same issue, with a similar conclusion.

[JBinCBad]

Great Thread

Hey guys, new here but about to jump into the solar game as well, I'm in Carlsbad and almost signed with the second estimate given, without considering the brand/model of panels, microinverters vs. SE, etc. This thread has educated me a lot.

Subdriver, can you please PM me your install co. info? Apparently I can't PM until I have 10 posts.

I'm also considering the SE inverter vs. microinverters, and will need to read up more on that, but this forum seems a good place to start for relevant info.

Thanks for all the info,
Joel

[J.P.M.]

Hey guys, new here but about to jump into the solar game as well, I'm in Carlsbad and almost signed with the second estimate given, without considering the brand/model of panels, microinverters vs. SE, etc. This thread has educated me a lot.

Subdriver, can you please PM me your install co. info? Apparently I can't PM until I have 10 posts.

I'm also considering the SE inverter vs. microinverters, and will need to read up more on that, but this forum seems a good place to start for relevant info.

Thanks for all the info,
Joel

FWIW, There are folks in Carlsbad who used the same contractor. See recent posts.