9.5KW + 2 PW all installed. Permanent rejection from LA County

[Kodemonkey]

I have a 28 panel installation that was performed on 1/13/2021. My house faces due south (183 degrees) and has 14 panels on a west facing roof and 14 on an East facing roof with 23 degree slope. This is the absolute maximum number of panels my roof can hold.

Originally they were going to install a solar edge 7600 and that would have been fine. But since Tesla is now making their own inverter, rumor has it they are not buying SE inverters anymore. So they gave me a SE 10,000. Overkill but should not be a problem. But I was worried that the county doesn't want an inverter on a 60A breaker in a 125A load center with that size inverter. Even though the system cannot be expanded (well, maybe later panels of the same size will be 450W and could be upgraded - but probably not cost effective). Load Center Y is actually incorrect in 2 places. Now the inverter has a 60A breaker, and there is an additional 100A breaker that goes to the main. It doesn't actually go straight back to Load center V.

So now they are escalating it at the County. Not sure what good that will do. If anyone has any ideas I am open to them...

 

[jjrandorin]

is your thread title supposed to read "permit rejection" instead of permanent rejection?

 

[Kodemonkey]

The field guy used the word "permanent rejection". When I look it up on the LA EPIC (planning website), nothing has been updated. I may have heard him wrong, but the sound in his voice was pretty deflated. But I could have misheard him.

ETA : Yeah, I had to have misheard him. I know with a neighbor down the street, they had to start all over - new permit applications because Tesla forgot one minor thing - the 2 powerwalls.

 

[Kodemonkey]

Also, I have had the plans rejected 3 times. We may be just using different terminology. The above is plan #2, there is plan #3 that I am trying to get out of my project adviser. Maybe they fixed that, but I am trying to wrap my head around how this above plan is missing a breaker going to the TEG.

 

[jjrandorin]

It sounds like you ment to type "permanent" then. I thought it was a mistype so was going to correct it for you, but if thats what you ment to say, I will leave it. It could very well have been "permanent" rejection of that permit, meaning they need to make a correction somewhere and re submit again.

I am not up to date on all that, lol.

 

[holeydonut]

Has Tesla investigated whether you could upgrade your service to Class 200 (200 Amp) instead of just trying to make things fit within your old 125A setup? If you have above-ground service entry, it may be (relatively) easier to try and get a bigger service rating.

I suspect your issues are related to your rather large system and only 125 A rated main panel. I got 7.9 kWp installed and PG&E straight up would not allow the system to be coupled to what they erroneously thought was 125 A service. My situation was idiotic because I already had 200 A service, PG&E just kept thinking I only had 125 A and repeatedly blocking me.

While it's good that half of your 28 panels are facing opposite azimuth directions, I suspect your county and PoCo just don't care... but maybe upgrading to a 200 A service won't be a huge dent in the pocketbook.

PS, why do you have two 100 A breakers connected in series? Or is that second 100A coming off your main panel a 100 A breaker in Tesla Energy Gateway?

 

[wwhitney]

The drawing as shown, with a 7.6 kW inverter on a 40A breaker, is NEC compliant. You have a 100A feeder, with three connections: 80A continuous of inverter outputs (100A after 125% factor), a 100A grid connection, and a panel of loads protected by a 100A breaker. All is copacetic, there's no way to overload that feeder. (The load panel needs the 100A breaker, because the grid plus the inverters could otherwise together feed more than 100A to the panel).

Now, with the change to a 10.0 kW inverter, you are up to 90A continuous of inverter outputs (112A after 125% factor). So that potentially overloads the 100A feeder. Now if CA had adopted the 2020 NEC and its new section of 705.13, then you could use the fact that you can configure the Powerwall to limit the total inverter export to 80A continuous (100A non-continuous) to treat the inverter sources as 100A and everything would again be NEC compliant. And the AHJ could choose to allow the early use of NEC 705.13.

But if the AHJ does not do that, then you need to make a change. You could go back to a 7.6 kW inverter on a 40A breaker. Or assuming your service conductors are large enough, you could upgrade your service breaker to 125A (since you have a 125A panel shown there), and upgrade the feeder to 125A (at the three cross sections labeled 7 and 8 in your diagram).

Cheers, Wayne

 

[Kodemonkey]

Has Tesla investigated whether you could upgrade your service to Class 200 (200 Amp) instead of just trying to make things fit within your old 125A setup? If you have above-ground service entry, it may be (relatively) easier to try and get a bigger service rating.

I suspect your issues are related to your rather large system and only 125 A rated main panel. I got 7.9 kWp installed and PG&E straight up would not allow the system to be coupled to what they erroneously thought was 125 A service. My situation was idiotic because I already had 200 A service, PG&E just kept thinking I only had 125 A and repeatedly blocking me.

While it's good that half of your 28 panels are facing opposite azimuth directions, I suspect your county and PoCo just don't care... but maybe upgrading to a 200 A service won't be a huge dent in the pocketbook.

PS, why do you have two 100 A breakers connected in series? Or is that second 100A coming off your main panel a 100 A breaker in Tesla Energy Gateway?

To make things clearer:

1) They moved everything out of my main panel into a 225A panel (V) - the bottom got cut off so I repasted.
2) The only thing left in the main panel is a 100A breaker coming from the TEG and another 100A breaker for the grid tie.

What is hanging them up is the change in the inverter size - or it could be that the diagram doesn't show the 100A breaker in load center Y. Even in the description they only show a 40A (now a 60A because of the larger inverter) and (2) 30A breakers for the PWs.

I don't know how else you would send power from load center Y to TEG Z without putting a breaker on the rail.

Also, I have a ground service entry. But my main really shouldn't need an upgrade since not much is going to pass through it now. My total sum of loads on the 200A (V) is hasn't changed. My house is pretty efficient. The largest load I pulled last year was 5700W max. With the powerwalls on storm watch charging and a Tesla model Y charging I got up to 10K at the meter for the first time ever - but that was without solar feeding it.

 

[holeydonut]

But if the AHJ does not do that, then you need to make a change. You could go back to a 7.6 kW inverter on a 40A breaker. Or assuming your service conductors are large enough, you could upgrade your service breaker to 125A (since you have a 125A panel shown there), and upgrade the feeder to 125A (at the three cross sections labeled 7 and 8 in your diagram).

Cheers, Wayne

His diagram says his main panel is already a 125 A rated panel. Would that be ok as shown? I figured he had to go up to 200 A if he were stepping up.

 

[wwhitney]

PS, why do you have two 100 A breakers connected in series? Or is that second 100A coming off your main panel a 100 A breaker in Tesla Energy Gateway?

Likely it was an existing meter main, they pulled all the loads out, and using a 100A branch breaker was the easiest way to connect to the panel bus.

His diagram says his main panel is already a 125 A rated panel. Would that be ok as shown? I figured he had to go up to 200 A if he were stepping up.

Nothing wrong with a 125A breaker in a 125A panel. The question is whether the service conductors from the utility to the panel are rated for 100A or 125A.

Cheers, Wayne

 

[Kodemonkey]

The drawing as shown, with a 7.6 kW inverter on a 40A breaker, is NEC compliant. You have 100A feeder, with three connections: 80A continuous of inverter outputs (100A after 125% factor) a 100A grid connection, and a panel of loads protected by a 100A breaker. All is copacetic, there's no way to overload that feeder. (The load panel needs the 100A breaker, because the grid plus the inverters could otherwise together feed more than 100A to the panel).

Now, with the change to a 10.0 kW inverter, you are up to 90A continuous of inverter outputs (112A after 125% factor). So that potentially overloads the 100A feeder. Now if CA had adopted the 2020 NEC and its new section of 705.13, then you could use the fact that you can configure the Powerwall to limit the total inverter export to 80A continuous (100A non-continuous) to treat the inverter sources as 100A and everything would again be NEC compliant. And the AHJ could choose to allow the early use of NEC 705.13.

But if the AHJ does not do that, then you need to make a change. You could go back to a 7.6 kW inverter on a 40A breaker. Or assuming your service conductors are large enough, you could upgrade your service breaker to 125A (since you have a 125A panel shown there), and upgrade the feeder to 125A (at the three cross sections labeled 7 and 8 in your diagram).

Cheers, Wayne

Moving from the 7.6KW to the 10KW wasn't my decision. Tesla upsized it because they can't source a 7.6KW SE. Probably because they aren't buying them anymore. I really don't want the new Tesla inverter. I don't want to be a test subject. But I have a feeling that might end up going that direction.

 

[Kodemonkey]

Likely it was an existing meter main, they pulled all the loads out, and using a 100A branch breaker was the easiest way to connect to the panel bus.



Nothing wrong with a 125A breaker in a 125A panel. The question is whether the service conductors from the utility to the panel are rated for 100A or 125A.

Cheers, Wayne

Bingo - you are correct, the panel that has the 2 - 100A breakers is my service main. It's weird all the breakers are still in it - just disconnected and turned off. I am assuming that is to keep from having an exposed bus and easier than screwing a blank over it.

All I know if that the meter is rated at 200A and my service on my SCE bill states 100A.

 

[h2ofun]

Boy is this the pits. One of the reasons I m reviewing my drawings to help try to avoid surprise. I also am upgrading everything to much larger than I need now, like 2 11.4K inverters, so the wiring, breakers, etc are all sized for any possible future enhancements. Cost wise not smart, but future proofing is what I like to attempt to do. Seems getting what they speced is the easier solution for you.

 

[wwhitney]

Yeah, so if the AHJ won't allow Tesla to use 2020 705.13 early, then Tesla will have to choose one of the two solutions I described.

Bingo - you are correct, the panel that has the 2 - 100A breakers is my service main. It's weird all the breakers are still in it - just disconnected and turned off. I am assuming that is to keep from having an exposed bus and easier than screwing a blank over it.

That may be the case, but it's not sufficient for the NEC, the breakers have to be removed. The relevant code section [2017 NEC 705.12(B)(2)(3)(c)] refers to "overcurrent devices on panelboards," which doesn't distinguish between breakers without any connection and those with. The breakers need to come out, and the dead front needs to have the holes filled in.

Cheers, Wayne

 

[wwhitney]

Boy is this the pits. One of the reasons I m reviewing my drawings to help try to avoid surprise. I also am upgrading everything to much larger than I need now, like 2 11.4K inverters, so the wiring, breakers, etc are all sized for any possible future enhancements. Cost wise not smart, but future proofing is what I like to attempt to do. Seems getting what they speced is the easier solution for you.

If I recall, your current plan is to have one 200A service with (1) 11.4 kW inverter and (3) Powerwalls, and another service with (1) 11.4 kW inverter and (2) Powerwalls. So that's 150A of inverter output current (after the 125%) on one service, and 120A on the other. Which should be fine on a 200A feeder with 3 connections like in the above diagram.

BTW, that also means that if you have considered (1) 11.4 kW inverter and (5) Powerwalls on one 200A service, you'd have the same problem as the OP. It would only be possible with the use of 2020 705.13 on Power Control Systems, so either with your AHJ has to let you use that early, or you have to wait until CA adopts the 2020 NEC (maybe January 1, 2023?). [But a 9.6 kW inverter and (5) Powerwalls would be OK.]

Cheers, Wayne

 

[holeydonut]

Bingo - you are correct, the panel that has the 2 - 100A breakers is my service main. It's weird all the breakers are still in it - just disconnected and turned off. I am assuming that is to keep from having an exposed bus and easier than screwing a blank over it.

All I know if that the meter is rated at 200A and my service on my SCE bill states 100A.

Since Tesla won't let you swap the inverter, you'll need to speak with the planning department of SCE to see if they can send a QEW to your house and inspect if your service entry can support 125 A on the line (PoCo) side. If things work out well, I think Wayne's proposal of you putting in a 125 A main breaker and fixing the deadfront should suffice.

Assuming SCE is like PG&E, the contractor must allow the homeowner to gain access on their own permit application. Tesla should be able to provide you with your application data with SCE and you can hop on the phone and try to do the legwork to get a QEW out to your house for an inspection with their eyes. Don't rely on the PoCo line diagrams or your bill; having someone get eyes on it will go a long way.

 

[wwhitney]

If things work out well, I think Wayne's proposal of you putting in a 125 A main breaker and fixing the deadfront should suffice.

That proposal also requires upsizing 3 feeder segments (unless they happen to oversize them already), so it is definitely more work than getting a 7.6 kW inverter.

Cheers, Wayne

 

[holeydonut]

That proposal also requires upsizing 3 feeder segments (unless they happen to oversize them already), so it is definitely more work than getting a 7.6 kW inverter.

Cheers, Wayne

Lol, maybe Kodemonkey needs to just buy his own 7.6 kW Solaredge and sell it to Tesla for this project haha.

 

[h2ofun]

If I recall, your current plan is to have one 200A service with (1) 11.4 kW inverter and (3) Powerwalls, and another service with (1) 11.4 kW inverter and (2) Powerwalls. So that's 150A of inverter output current (after the 125%) on one service, and 120A on the other. Which should be fine on a 200A feeder with 3 connections like in the above diagram.

BTW, that also means that if you have considered (1) 11.4 kW inverter and (5) Powerwalls on one 200A service, you'd have the same problem as the OP. It would only be possible with the use of 2020 705.13 on Power Control Systems, so either with your AHJ has to let you use that early, or you have to wait until CA adopts the 2020 NEC (maybe January 1, 2023?). [But a 9.6 kW inverter and (5) Powerwalls would be OK.]

Cheers, Wayne

I was going to put 4 PW's on one inverter but became too messy. So yep, 3 and 2 is what I hope we get back to county this week.

 

[Kodemonkey]

Yeah, so if the AHJ won't allow Tesla to use 2020 705.13 early, then Tesla will have to choose one of the two solutions I described.


That may be the case, but it's not sufficient for the NEC, the breakers have to be removed. The relevant code section [2017 NEC 705.12(B)(2)(3)(c)] refers to "overcurrent devices on panelboards," which doesn't distinguish between breakers without any connection and those with. The breakers need to come out, and the dead front needs to have the holes filled in.

Cheers, Wayne

Thanks for the info. I appreciate it. I will bring it up.