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  • DeFreitas Enterprises
    replied
    Okay finally got my design over to the Electrical PE for stamping. We are trying to qualify this under 2017 NEC 705.12(B)(2)(3)(b).

    Inverter Output = 1.21 Amps
    (53)*1.21 = 64.13 Amps
    64.13 * 1.25 = 80.1625

    Let's round that down ever so slightly to 80.0

    Decrease main breaker size from 200 Amps to 150 Amps.

    150+80 = 230 Amps which is less than 120% of 200 amp rated busbar.

    Only consideration here is the backfeed breaker needs to be on the opposite end of the busbar if I am understanding the code correctly.

    Here is a link to my line diagram design and some site pictures of the electrical room. LMK if this link doesn't work.

    https://drive.google.com/open?id=1Xu...GlxIIa4pMo4N_m

    -Alex

    Leave a comment:


  • jaggedben
    replied
    Originally posted by DeFreitas Enterprises View Post
    Could you elaborate a bit on what these breakers accomplish? I am having a hard time seeing the application. Does this replace the main breaker and allow a feed thru? How would that accomplish NEC compliance considering the bus bar overloading?

    I really appreciate all the help with this project.
    Basically I was just pointing out that your electrician is theoretically right when you made the following statements in your original post...

    ...My electrician seems to think we will be able to use a 200 amp breaker like any other subpanel install, but I think he may be mistaken here. I can't imagine the size of the terminals to accept the proper sized wire for 200 amps. I have only seen 100 amp breakers, never anything higher....
    He's theoretically right in that 200A branch breakers do exist.
    With that said, I've never done an install with these breakers either, because it just seemed unfeasible or not economic compared to other options in residential. Wrestling with 3/0 cu in an existing resi panelboard and possibly splicing it inside an existing enclosure that is already pretty full is not my cup of tea. You've got to be able to actually get cable or conduit in and out; if all the walls are finished you need to be a carpenter, or hire one... I've done the subpanel thing plenty of times with 100-125A but that's often hard at those wire sizes. So I've always done a main breaker downsize or found a way to get to the existing subpanel or something.

    Ultimately the best answer will depend on details specific to the job.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by jaggedben View Post
    As far as the subfeed lugs and breakers, those are all options with their own conderations. But what I had in mind was breakers such as the Homeline 2200BB or the Eaton BJ2200.
    Could you elaborate a bit on what these breakers accomplish? I am having a hard time seeing the application. Does this replace the main breaker and allow a feed thru? How would that accomplish NEC compliance considering the bus bar overloading?

    I really appreciate all the help with this project.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    The client just closed their solar loan so I am finally able to proceed with this installation. Before I submit for utility interconnection I need to have my electrical 1 and 3 line stamped by my PE, and I will upload my design here so y'all can give feedback.

    I am still a bit confused with designing the solar subpanel to be NEC compliant on the load side of the main breaker, but hoping it makes more sense once I go on AutoCAD for a few hours. The easiest solution is to just interconnect on the supply side of the main breaker, but that won't make for a seamless battery installation like I promised the client I would set up this system for with a dedicated solar + storage + critical loads panel.

    Putting the solar + critical loads + storage subpanel on the load side of the main breaker requires downsizing the main breaker as previously discussed. Decisions decisions...

    -Alex

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by jaggedben View Post
    You're paying too much. . But I agree with the point.
    Haha touche! Okay my latest quote is at $377.30 for the IQ Envoy alone, for this job. Maybe I was exaggerating to try and make my point more reasonable

    Some vendors are more then others. Maybe one day I'll have the in and order straight from Enphase.

    Leave a comment:


  • jaggedben
    replied
    Originally posted by DeFreitas Enterprises View Post
    The IQ Envoy itself costs like $425-$450, and a MLO panel another $80 or so. The Enphase AC Box ($490-$500) comes with the Envoy pre-wired and space for (4) branch ...
    You're paying too much. . But I agree with the point.

    Leave a comment:


  • jaggedben
    replied
    Originally posted by ggunn View Post
    Why would you need specialized AC combiners? We just use regular MLO panels for AC combination.
    It's not so much specialized as done for you. Since the Envoy now needs to be on its own breaker, and in a 12x12x4 PVC box, you save the extra cost of supplying your own subpanel and box and you nearly come out even. Add the occasional instance where you have to make an extra trip to the job because you forgot to supply one of those items yourself, and you come out even more even. It also looks cleaner.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by ggunn View Post
    Why would you need specialized AC combiners? We just use regular MLO panels for AC combination.

    The IQ Envoy itself costs like $425-$450, and a MLO panel another $80 or so. The Enphase AC Box ($490-$500) comes with the Envoy pre-wired and space for (4) branch circuits of solar / batteries. It is NEMA 3R rated, and looks pretty sweet as well. It is a plastic enclosure so you have to use grounding lugs for EMT conduit coming in and out but other than that my electrician really likes the panel. They used to only hold (3) 20 amp branch circuits, but I bitched on LinkedIn and they came out with a larger version with an additional branch circuit.

    They basically started advertising that you can install the Enphase batteries right off their AC panel and I informed them they were glossing over the fact that you would drop down to only (2) branch circuits of solar if you used the third circuit for batteries. A couple months later the AC Combiner + was unveiled and now they are on the Combiner 3 which is a smaller unit but still has the (4) branch circuits.

    For this shipping container project I will have (5) branch circuits of solar, and additional circuits for the critical loads and battery backup (Enphase or traditional battery inverter), so I am looking to install a second 200 amp panel for this application. Which led to this thread of how to install a code compliant 200 amp subpanel for the purpose of solar + storage + critical loads.

    Leave a comment:


  • ggunn
    replied
    Originally posted by DeFreitas Enterprises View Post
    I ran into a similar issue late in 2018 where the AC combiner boxes ... were hard to find.
    Why would you need specialized AC combiners? We just use regular MLO panels for AC combination.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by Whalepod View Post
    Oh no, they're slimy in all kinds of different ways.

    I have PO's open since mid '18 for lots of equipment that haven't been fulfilled. I was forced to move to SolarEdge for all my resi installs because I just couldn't get equipment even on the open market, and there is a very SLIM chance I'll ever go back unless a very narrow set of conditions are met.

    But don't worry, they will offer customers an upgrade program to the same equipment that they can't even fulfill current orders for to fix all the problems they had with M190's.
    I ran into a similar issue late in 2018 where the AC combiner boxes and IQ7+ were hard to find. I purchase through the distribution network, not from Enphase directly. My distributors were able to quickly get more supply, and I purchased a couple jobs worth of IQ7+.

    The upgrade program is useless IMO because IQ8 is going to be such a gamechanger that I wouldn't advise someone upgrade to anything before. But the IQ series are a lot more reliable than the older units which my legacy clients have from other installers.

    SolarEdge is a vastly inferior product. The DC to DC optimizers fail just as much, if not more than the microinverters, and you have a central inverter as a single point of failure. There are a couple advantages, you can fit a larger DC system size on a 10 kW AC inverter and remain a simplified interconnection here in MA and receive full net metering credits.

    The StorEdge inverter is also pretty sweet, and allows a much simpler seamless storage solution by pairing the PV and Storage inverter with a Powerwall or LG Chem, etc.

    The extra service of SolarEdge optimizers and single point of failure of a central inverter are why I am die hard Enphase. AC wiring is simpler as well. Now that the EGC and GEC is not part of the trunk cable like it was with the M250 and S280 versions, we have to pull up a #6 THWN for grounding so that kind of blows.

    Originally posted by jaggedben View Post
    Having business problems isn't the same as being slimy. Enphase has been open with distributors about what's going on in a way that Tesla never would be. They've been hit with tariffs like many. Also, how is it slimy to offer past customers below-cost replacement of an inferior product 8 years later? What company in any industry have you ever heard of being that generous?
    SolarEdge has its own problems, you'll find out. But there are reasons these companies are at the top of the market right now.
    The only correlation between Enphase and TESLA is how Enphase is delaying IQ8. TESLA has unveiled and delayed pretty much every single one of their products. The Solar Roof was the worst of the worst, as I have literally lost multiple clients who are "waiting for the TESLA roof". In the time period they have been waiting, the lucrative SREC program has ended in MA, and soon the 30% tax credit will start stepping down. Instead of buying traditional roof mounted panels, receiving all incentives, paying off within 4-6 years, and then exploring the solar roof in 7-10 years when more economical and ACTUALLY AVAILABLE, these potential clients are now waiting for a product that likely won't be offered in 2014 or 2017 code compliant states for another few years.

    The whole solar roof has been a freaking farce and a joke. I am so disappointed that Elon Musk literally hurt so many of the long tail of installers by promising a product he likely knew would NEVER be able to make it to the market like he promised (Summer of 2017). The fact that he is taking $1000 deposits from homeowners is another farce, as a lot of these people actually need roof replacements. What happens when they desperately need to do have the roof done, but have left a deposit for the solar roof which won't be offered in their state for 2-4 years down the road? What happens is these people then need traditional roofing solution, and have missed out on solar incentives and tax credits they would have had if they didn't "wait for the TESLA roof".

    Anyways, rant over. Will update on this design as we continue through the process.

    Thanks for all your help.

    -Alex

    Leave a comment:


  • jaggedben
    replied
    Originally posted by Whalepod View Post
    Oh no, they're slimy in all kinds of different ways.

    I have PO's open since mid '18 for lots of equipment that haven't been fulfilled. I was forced to move to SolarEdge for all my resi installs because I just couldn't get equipment even on the open market, and there is a very SLIM chance I'll ever go back unless a very narrow set of conditions are met.

    But don't worry, they will offer customers an upgrade program to the same equipment that they can't even fulfill current orders for to fix all the problems they had with M190's.
    Having business problems isn't the same as being slimy. Enphase has been open with distributors about what's going on in a way that Tesla never would be. They've been hit with tariffs like many. Also, how is it slimy to offer past customers below-cost replacement of an inferior product 8 years later? What company in any industry have you ever heard of being that generous?
    SolarEdge has its own problems, you'll find out. But there are reasons these companies are at the top of the market right now.

    Leave a comment:


  • Whalepod
    replied
    Originally posted by DeFreitas Enterprises View Post
    At least Enphase isn't as slimy on unveiling then delaying products like TESLA (solar roof, etc).

    Oh no, they're slimy in all kinds of different ways.

    I have PO's open since mid '18 for lots of equipment that haven't been fulfilled. I was forced to move to SolarEdge for all my resi installs because I just couldn't get equipment even on the open market, and there is a very SLIM chance I'll ever go back unless a very narrow set of conditions are met.

    But don't worry, they will offer customers an upgrade program to the same equipment that they can't even fulfill current orders for to fix all the problems they had with M190's.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by jaggedben View Post
    Read the section I quoted again. The 120% rule isn't the only rule anymore. I quoted the 2017 reference since you appear to be in MA.

    As far as the subfeed lugs and breakers, those are all options with their own conderations. But what I had in mind was breakers such as the Homeline 2200BB or the Eaton BJ2200.
    Well that explains it, haven't opened my code book since NEC 2014.

    Looked it up more in depth and thank you for the extra nudge. Here's a link I found explaining the section.

    https://www.jadelearning.com/2014-ne...ions/image3-2/

    I think I understand that code change. Basically move enough loads to the subpanel, and keep the OCPD of the subpanel + remaining loads in the MSP below 200 amps and it is in code.

    What exactly do those breakers you referenced accomplish? I looked them up but am not really following.

    They are also referenced in this thread from this forum, which is pretty much exactly what I am trying to do, install a second 200 amp panel. They also mention going up to a 400 amp meter socket with double lugs. This may be a more cost effective route if I were the electrician, but since I am not I have to consider his time on site. It may be more cost effective for my bottom line to use an expensive breaker and keep it simpler than replacing the meter socket and re-pulling feeders.

    https://forums.mikeholt.com/showthread.php?t=134839

    Hopefully I can understand those breakers a bit more tomorrow after some sleep

    Leave a comment:


  • jaggedben
    replied
    Read the section I quoted again. The 120% rule isn't the only rule anymore. I quoted the 2017 reference since you appear to be in MA.

    As far as the subfeed lugs and breakers, those are all options with their own conderations. But what I had in mind was breakers such as the Homeline 2200BB or the Eaton BJ2200.

    Leave a comment:


  • DeFreitas Enterprises
    replied
    Originally posted by jaggedben View Post
    One strategy is to move enough loads out of the MSP (to the critical loads panel) to qualify the MSP under 705.12(B)(2)(3)(c).
    Thanks for rolling onwards with this design. So I google searched this and came back across another posting on this forum which discussed this. Some of you are on that thread as well

    https://forums.mikeholt.com/showthread.php?t=188070

    The details of that are getting a bit over my head. I do have some experience with the NEC, code complaince, etc. But my background is Mechanical Engineering, and my electrical work and code knowledge has all been learned in the field and doing research. I worked on commercial solar design for a year before starting my own company, so residential electrical design was never studied or practiced. I converse with my master electrician, but a lot of this design work is above his skill level. I generate all the 1 and 3 lines for my projects. I think this forum is going to be invaluable as well, so I thank you all tremendously for helping me out. I will definitely post pictures and the finished installation when we get to that point.

    I did some research on feed thru lugs, and came across this schematic by Schneider.

    Click image for larger version

Name:	SF lugs, FT lugs, SF Breaker.jpg
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    Is this what you would be referring to? The last two options seem like it would be the same scenario as the 120% rule, basically being able to send 200 amps to the bus from the main breaker, and the 60 or 80 amps from the backfeed solar as well. But the first option, the Sub Feed Lug, seems like it may work in that you would still be protected by 200 amps for the main breaker?


    That being said, I am not really following what simply moving enough loads out of the MSP would accomplish? Is the idea to downsize the main breaker to then be able to backfeed? I thought the 120% rule was based off the main breaker size only, not necessarily the ampacity rating of the bus. (If you downsize to 100 amp main breaker you would be limited to 20 amp backfeed). That wouldn't really make sense from a physics standpoint, as the bus can definitely handle 100 amps + 80 amps solar, but I thought the code was simply 120% main breaker rating, which is 40 amp backfeed for 200 amp main breaker, 20 amp backfeed for 100 amp main breaker.

    Leave a comment:

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