4.5kW SolarEdge/LG System coming soon to San Diego

[JBinCBad]

Thanks JP, I saw that, but they didn't ID installer and I can't PM without 10 posts, so I was hoping they could PM me. . .

[subdriver97]

Thanks JP, I saw that, but they didn't ID installer and I can't PM without 10 posts, so I was hoping they could PM me. . .

PM Sent. =)

[JBinCBad]

Thanks

Thanks Robert and Jim, I drafted you both replies with thanks, but it appears I can't reply to PM's without 10 posts either. Since my home has shading issues with a couple roof areas, I will have to remove and replace some passive thermal panels for my pool, probably to one of my northern roofs, so I have factor that into my budget. Rooftop space will eventually be an issue, as we hope to eventually get electric cars as well, but for now eliminating our electrical bill is a good start. Our bill is only approx $168/mo, and I was planning on doing a 4.5kW system, hopefully expanding to more if /when we get cars or central AC, and the only thing I'm hedging on is whether to do microinverters or the SE system. I'm slowly educating myself and appreciate all the info from this forum.

Cheers,

Joel

[thejq]

You're welcome. Whatever you do, make sure to leave the SW and/or S side of the roof for PV. SW is best if EV-TOU is considered. Depending on how bad the shading is, 4.5KW might produce more than you need with $165/mon bill. Being in the same city, you can look at my production (signature) to get an idea. Feel free to email me for specific questions.

FYI, here is my old thread where I discussed why I made the choices I made. http://www.solarpaneltalk.com/showth...-just-finished

[J.P.M.]

Thanks JP, I saw that, but they didn't ID installer and I can't PM without 10 posts, so I was hoping they could PM me. . .

You're welcome. I didn't want to speak for others but happy they saw the need and responded.

[JBinCBad]

Thanks guys, my wife still runs around the house unplugging everything at night, she's quite frugal, so maybe this will relax her a bit. . . I am bummed we missed the CSI incentive, but the 30% fed is still nice, so I'll talk to the recommended installers.

[subdriver97]

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.

I had a discussion today with my vendor and he brought up the same point regarding the SE5000.
SE6000 max cont. output = 25A, * 125% = 31.25A
SE5000 max cont. output = 21A, * 125% = 26.25A
SE3800 max cont. output = 16A, * 125& = 20A

Interestingly, I'm using the same vendor as thejq, so I should probably bring up that he indeed installed a SE6000 (that's what the thejq has) with a 25A breaker.

Assuming my only option is the SE3800 to comply with NEC 2011, I thought of the following:
1. Can the main breaker be degraded further to 95A or 90A to accommodate a 30A solar breaker?
2. Maybe I should consider Enphase, at least then if I want to expand I won't be limited by a SE3800. When I want to add more panels I will just need to do a service panel upgrade.

My immediate thought is I shouldn't just bite the bullet and buy into the service panel upgrade. Cash in hand is more worthwhile to me. Also the vendor is charging $2500 for the service panel upgrade so it would cheaper for me to have a difference vendor do it even considering if I don't have the 30% tax credit.

[thejq]

Interestingly, I'm using the same vendor as thejq, so I should probably bring up that he indeed installed a SE6000 (that's what the thejq has) with a 25A breaker.

No, I have the 30A breaker installed not 25A with SE6000 (and passed inspection without a problem). In a previous post, I thought 25A was good enough for SE5000, of course without the 1.25 factor.

[subdriver97]

No, I have the 30A breaker installed not 25A with SE6000 (and passed inspection without a problem). In a previous
post, I thought 25A was good enough for SE5000, of course without the 1.25 factor.

SE6000 max cont. output = 25A, * 125% = 31.25A
SE5000 max cont. output = 21A, * 125% = 26.25A
SE3800 max cont. output = 16A, * 125& = 20A

Hmm, so 30A is still < 31.25A... Maybe if I can schedule your inspector I can get away with a 25A for the SE5000.

It's interesting to me that 690.8(A) stipulates a minimum rating for the over current device. I would have thought it would be max rating. I assume that the 125% is to accommodate current spikes... but from a safety standpoint I would think it's safer to have a lower rated breaker than a higher rated breaker... I suppose the regulation is using it as a forcing function to ensure the service panel is of adequate rating to handle the PV system... I still don't see how it would be a safety issue to use a smaller breaker if you know that you won't be using the full capacity of the inverter... the service panel would still see less than the main breaker + pv breaker, as long as that is less than the service panel rating.... how is that a bad thing?

[sensij]

The problem isn't 690.8(A), it is 215.3. All breakers can only be loaded to 80% continuously. UL defined continuously as 3 hours at one point, although with an inverter that is listed to supply 21 A continuous, there isn't any wiggle room. The reason for the derating has to do with how the breakers are designed and tested, there is a little bit more here, if you are interested.

One of the changes in the 2014 NEC is with respect to how the possible load on the busbar is calculated. In 2011 NEC, the sum of the supply breakers is used. In 2014 NEC, Section 690 has been revised and will allow 1.25 of the inverter continuous rating to be used, instead of the breaker size. In practice, I think this only really helps when there is more than one small circuit, as in multiple strings of microinverters each protected by a 20 A breaker. In this case, it wouldn't help, because 26.5 + 100 is still over the rating of the busbar. In other words, even if you put a smaller breaker in, the 2014 NEC would still disallow it.

From a common sense perspective, the max load on the opposite side of the center feed from the PV source needs to be less than the main breaker. If I'm seeing your picture correctly, you have the following on each leg:
20
15
?? - A/C (at least 20)
?? - Dryer (at least 20)
100 - Main
15
15
15
20
20
20
50

As long as the ?? add up to <= 65 A, your loads might be OK.

Whether or not the inverter will really output 21 amp continuously with your array isn't the point. Code isn't created to allow your specific installation, it attempts to protect against reasonable modifications that might be made to your system over time. The whole point of putting a larger inverter in would be to allow for array expansion later, and it would be awfully tempting to just put up a couple more solar panels in a few years without paying for the service panel upgrade at that time, too.

If your installer is recommending a panel upgrade, I don't really see a good basis to object to that.

[SoCalsolar]

Amp wise your 5000w inverter ought to be ok

Amp wise your 5000w inverter ought to be ok. It sounds like your main panel is derated from a 125 to 100amp. This would free up an extra 25 amps giving you up to 50 amps for the solar. If you had a 100 amp panel then yes you would be limited to a 3800w inverter. It seems there is either a space issue (no room for the breakers) or more than likely a center fed issue. each AHJ (area having jurisdiction) uses whatever code book they decide. Some cities are in 2011 others 2014 and some are stuck on 2008. If your AHJ is particular about center fed as many are you won't pass inspection till the panel is changed out. The center fed main not complying with code is becoming more and more of a standard in SoCal. Ask the installer why the panel won't work? Unless I missed that one of the earlier posts has the installer commented on this yet?

[J.P.M.]

Why not just call the county and ask ? While talking to them, ask that the building inspector for your area give you a call. It can be done.

[JBinCBad]

Out of curiosity, what does EV-TOU represent? I'm guessing EV is electric vehicle, but TOU?

[QUOTE=thejq;131975]You're welcome. Whatever you do, make sure to leave the SW and/or S side of the roof for PV. SW is best if EV-TOU is considered. Depending on how bad the shading is, 4.5KW might produce more than you need with $165/mon bill.

[J.P.M.]

[QUOTE=JBinCBad;132057]Out of curiosity, what does EV-TOU represent? I'm guessing EV is electric vehicle, but TOU?

You're welcome. Whatever you do, make sure to leave the SW and/or S side of the roof for PV. SW is best if EV-TOU is considered. Depending on how bad the shading is, 4.5KW might produce more than you need with $165/mon bill.

TOU = Time Of Use as opposed to tiered rates. There are several of each type and at least one blend of both types if the SDG & E tariff schedule is to be believed.

[thejq]

[QUOTE=J.P.M.;132058]

TOU = Time Of Use as opposed to tiered rates. There are several of each type and at least one blend of both types if the SDG & E tariff schedule is to be believed.

Yes, that's right. Additionally the importance of EV-TOU is that the current rate during the summer (May-Oct) is 49c/KWh during peak (12-6PM), and 16c/KWh during super off peak (12-5AM). With net metering, for every 1 KWh excess production during peak, you can bank it and use 3 KWh during super off peak to charge your EV and still owe zero $. So to cover your EV charging, you might not need to budget 100% in solar capacity. My rough rule of thumb is 1.5x, so if you need 600KWh/month for charging, your EV solar capacity needs to be roughly around 400KWh/month.