What is preventing this solar + PW system from garage installation? (NorCal, PG&E)

[wattsup]

I am in the Bay Area of Northern California, in PG&E territory.

Tesla recently completed the site assessment for my solar + whole-home backup PW install and, despite my indicated preference for a garage installation, and prior discussions with my Tesla advisor about it, Tesla has provided a plan set with all equipment being mounted on an outside wall (a side wall) adjacent to the service meter (which is outside, on the same wall) and behind the fenced-in portion of that wall (a detail called-out in the plans).

When I questioned my Tesla advisor about why the plan set doesn't reflect the requested garage installation, he seemed to imply that something in my jurisdiction might be preventing it.

But... I have been in contact (at length) with my local city and fire officials (well before the site assessment) and have confirmed and re-confirmed that there should be no issues with a garage installation, provided that a hard-wired, interconnected heat detector is installed. (This is the only requirement currently unmet; all other requirements are already met.)

I discussed the idea that I would have the required heat detector installed with my Tesla advisor (again, well before the site assessment).

I can also provide up to 26' of uninterrupted wall space inside the garage, which is more than enough for the desired PWs (even with the ridiculous 3' spacing currently required by my jurisdiction) and which I believe the site assessors observed. I also mentioned this to my advisor early on, and to the assessors during their visit.

Now, I do currently have a tool pegboard and some minor shelving mounted on the target wall. Is Tesla so "unreasonable" in their site assessment that they don't account for the fact that I would, of course, remove those things prior to installation? Is this issue potentially as mind-numbingly dumb as, "yeah, we saw some stuff on the wall, so no garage install"?

If not that, then does anyone see something in the proposed system diagram below to indicate that all the new equipment CAN ONLY be installed outside, next to the existing meter and main breaker?

The one potential caveat being that the existing meter and main breaker are on the opposite side of the house from the garage (and distribution panel). Even with this caveat, can anybody suggest a reason why the new equipment CANNOT be located inside the garage?

In my view, Tesla could just as easily tap into the main service lines inside the garage (just before they reach the distribution panel) as they could outside (just as they leave the main breaker), no? In both cases, the system diagram would look identical.

The plans also call for an "emergency stop" switch to be installed outside (near the meter), feeding a 12V stop signal to the PWs. But, that would only be a matter of a bit more conduit/wiring, if the PWs were inside the garage, right? (Btw, I'm not certain why the stop signal is not shown connecting to all four PWs in the diagram; only two. Mistake?)

 

[CrazyRabbit]

Ask that they not parallel the home run to the third inverter. I’m in Texas with 8 powerwalls installed in the garage, bollards and interconnected heat detector required was all that was required, last December.
I think someone at the local office does the engineering. The guy who came out for the inspection told the inspector that he hated this installation, right in front of me. The dude shows up for inspection, and starts ripping off stickers that were correct, I had to stop him. He was a idiot.
I get the feeling that they only want to do it their way, definitely not the Burger King of solar installers. But I got it my way, almost!

 

[KHYE]

I don't know the jurisdiction by your area. But if you have confirmed with your local authority on the possibility, you need to keep calling Tesla until someone who is willing to spend time to look into this.

The on site assessor was just there to snap lots of pics, he didn't document all the details that I told him. I had to go back and forth with Tesla on my PW installation location and it took almost 3 months to get them to agree to the location I preferred.

After plan is all signed and approved, on the morning of installation, the lead electrician still insisted to install PW in another location because he was too lazy to run/pull long wires to the garage. He wasted 1 hr on the phone to keep checking with their design team and they told him no. He had no choice but stick to the plan. You have to watch them every step of the way until it's done to your expectations, my experience with Tesla solar is not hands off at all.

 

[holeydonut]

I am in the Bay Area of Northern California, in PG&E territory.

Tesla recently completed the site assessment for my solar + whole-home backup PW install and, despite my indicated preference for a garage installation, and prior discussions with my Tesla advisor about it, Tesla has provided a plan set with all equipment being mounted on an outside wall (a side wall) adjacent to the service meter (which is outside, on the same wall) and behind the fenced-in portion of that wall (a detail called-out in the plans).

When I questioned my Tesla advisor about why the plan set doesn't reflect the requested garage installation, he seemed to imply that something in my jurisdiction might be preventing it.

But... I have been in contact (at length) with my local city and fire officials (well before the site assessment) and have confirmed and re-confirmed that there should be no issues with a garage installation, provided that a hard-wired, interconnected heat detector is installed. (This is the only requirement currently unmet; all other requirements are already met.)

I discussed the idea that I would have the required heat detector installed with my Tesla advisor (again, well before the site assessment).

I can also provide up to 26' of uninterrupted wall space inside the garage, which is more than enough for the desired PWs (even with the ridiculous 3' spacing currently required by my jurisdiction) and which I believe the site assessors observed. I also mentioned this to my advisor early on, and to the assessors during their visit.

Now, I do currently have a tool pegboard and some minor shelving mounted on the target wall. Is Tesla so "unreasonable" in their site assessment that they don't account for the fact that I would, of course, remove those things prior to installation? Is this issue potentially as mind-numbingly dumb as, "yeah, we saw some stuff on the wall, so no garage install"?

If not that, then does anyone see something in the proposed system diagram below to indicate that all the new equipment CAN ONLY be installed outside, next to the existing meter and main breaker?

View attachment 929435

The one potential caveat being that the existing meter and main breaker are on the opposite side of the house from the garage (and distribution panel). Even with this caveat, can anybody suggest a reason why the new equipment CANNOT be located inside the garage?

In my view, Tesla could just as easily tap into the main service lines inside the garage (just before they reach the distribution panel) as they could outside (just as they leave the main breaker), no? In both cases, the system diagram would look identical.

The plans also call for an "emergency stop" switch to be installed outside (near the meter), feeding a 12V stop signal to the PWs. But, that would only be a matter of a bit more conduit/wiring, if the PWs were inside the garage, right? (Btw, I'm not certain why the stop signal is not shown connecting to all four PWs in the diagram; only two. Mistake?)

With all the myriad AHJs in the SF Bay Area, I think people will need to know the city/county you're in (or if you're in unincorporated).

For example...

If you're in Palo Alto, you're just plain screwed.
If you're in Santa Clara County, you'll end up with twenty-bazillion bollards in your garage if you install indoors.

 

[BGbreeder]

@wattsup Can I ask why you want them in a garage instead of outside, near the other panels?

Just to be clear; your current house wiring has the meter and main service panels on opposite sides of the house, and the meter is adjacent to the garage? Where does/will the solar land?

Just curious.

All the best,

BG

 

[wattsup]

@wattsup Can I ask why you want them in a garage instead of outside, near the other panels?

Just to be clear; your current house wiring has the meter and main service panels on opposite sides of the house, and the meter is adjacent to the garage? Where does/will the solar land?

Just curious.

All the best,

BG

The meter and main service panel (with just the main breaker) are on the opposite side of the house from the garage. The garage has the distribution panel (with all the circuit breakers).

I want the PW in the garage for protection (keep out of damp, salty coastal air) and to avoid complications with HVAC equipment I want to install on the same area Tesla is proposing for all their equipment.

The PW would be near the panels. My house is basically one big gable roof, with one plane (southern facing) to be nearly filled with panels. About half the panels (of the single large array) will be directly over the garage.

One can imagine that Tesla could easily punch directly down into the garage (from underneath the array) straight to the equipment.

 

[wattsup]

With all the myriad AHJs in the SF Bay Area, I think people will need to know the city/county you're in (or if you're in unincorporated).

For example...

If you're in Palo Alto, you're just plain screwed.
If you're in Santa Clara County, you'll end up with twenty-bazillion bollards in your garage if you install indoors.

I am in San Mateo County, on the coast. I have already discussed my potential garage installation with the local city building official and fire official, at length. Based on what they know, they are fine with it.

Interior side wall, 36” up, no bollards needed. All I am missing is a heat detector (but we have discussed things down the model number of an approved detector). There are no additional local restrictions, I am subject only to the 2022 CFC. They do, however, currently insist on 3’ separation (but I have the room for it).

 

[wattsup]

Ask that they not parallel the home run to the third inverter. I’m in Texas with 8 powerwalls installed in the garage

Thanks for the reply. Wow, 8 PW. Thanks for the advice to keep pushing Tesla.

What is the issue/advantage of avoiding a parallel run to the third inverter?

And which run? DC run between panels and inverter, or AC run between inverter and gateway’s load center?

 

[wattsup]

I am in the Bay Area of Northern California, in PG&E territory.

[snip]

[snip]

The plans also call for an "emergency stop" switch to be installed outside (near the meter), feeding a 12V stop signal to the PWs. But, that would only be a matter of a bit more conduit/wiring, if the PWs were inside the garage, right?

[snip]

@Vines, if I can bother you for advice...

Is there anything about Tesla's proposed whole-home backup design (above) that would require that it all be installed outside, instead of inside my garage? My local officials are fine with a garage install in theory, provided I have a heat detector installed; that is the only thing out of compliance.

My meter and main service panel (with just the main breaker) are located outside, on one side of the house. This is where Tesla wants to install everything, on an exterior wall behind my fence.

My garage and distribution panel (e.g., with all my household loads) are located on the opposite side of the house. I indicated to Tesla that my preference was to install on an interior garage wall. My advisor knew this, and I also mentioned it to the site assessors. (Though I got the impression they simply nod in friendly agreement, provide no specific opinions, nor take any notes.)

In either location, the solar array (a single, large array) is directly overhead, as it covers the roof side-to-side. Arguably, reaching equipment inside the garage is super easy, as conduit could simply be punched straight down from underneath the array.

Tesla has not yet explained precisely what is preventing my garage preference from being accommodated.

Could it be some kind of "line-of-sight" issue, since the main service panel is (and will remain) outside? (Though I imagine most people's meters are also outside, though perhaps not their MSP as well, and perhaps much closer to their garage/distribution panel.)

I am located in San Mateo County.

 

[CrazyRabbit]

I forgot to add that I had a pre-permit meeting with the building department. Tesla had me scheduled for install then canceled because of the changing rules. So I had to put them back on track, and told them of my meeting with the building department and dropped names and contacts.
I also had to argue with the installer about bollard placement…. I won. I always would back up my points with documentation.

 

[CrazyRabbit]

Thanks for the reply. Wow, 8 PW. Thanks for the advice to keep pushing Tesla.

What is the issue/advantage of avoiding a parallel run to the third inverter?

And which run? DC run between panels and inverter, or AC run between inverter and gateway’s load center?

On the wiring diagram you posted, the third inverter from the top (5.7 inverter), the two serial strings are shown paralleled in the combiner box on the roof.

Issue is shading, and all panels need to be on same array (azimuth and pitch). Just not worth it to save pulling wire and material cost.

 

[CrazyRabbit]

I used a Honeywell heat detector tied in to my alarm system, which is monitored for fire.

 

[wattsup]

On the wiring diagram you posted, the third inverter from the top (5.7 inverter), the two serial strings are shown paralleled in the combiner box on the roof.

Issue is shading, and all panels need to be on same array (azimuth and pitch). Just not worth it to save pulling wire and material cost.

Ah, thanks.

Well... my system does, in fact, meet those criteria. I will have a single array occupying one side of the large gable roof (which, luckily, is south facing, slightly south/east). There is no shading, not even from my own chimney.

Still an issue?

Btw, my design appears to have an average DC:AC ratio of about 1.0. (The three inverters are around 20 kW total, as is the solar array.) I was expecting Tesla to use only two inverters (in the two PW+'s), for a ratio closer to 1.35, but I was pleasantly surprised to see a third.

 

[Vines]

Ah, thanks.

Well... my system does, in fact, meet those criteria. I will have a single array occupying one side of the large gable roof (which, luckily, is south facing, slightly south/east). There is no shading, not even from my own chimney.

Still an issue?

Btw, my design appears to have an average DC:AC ratio of about 1.0. (The three inverters are around 20 kW total, as is the solar array.) I was expecting Tesla to use only two inverters (in the two PW+'s), for a ratio closer to 1.35, but I was pleasantly surprised to see a third.

There is no line of sight reason that I can see from my computer preventing them from doing your garage install. When equipped with the e-stop button and exterior combination service panel, the code is certainly satisfied. The code requires the grid, batteries, and pv modules can all be de-energized from the exterior of the building.

 

[wattsup]

There is no line of sight reason that I can see from my computer preventing them from doing your garage install. When equipped with the e-stop button and exterior combination service panel, the code is certainly satisfied. The code requires the grid, batteries, and pv modules can all be de-energized from the exterior of the building.

Thanks very much @Vines.

Right, the main 125A breaker (right after the combo service panel) and the e-stop button, if both used, would completely de-energize all circuits in the building, and the PV modules.

Follow-up question: What code does the other 125A breaker (depicted between the Tesla gateway and distribution panel) satisfy? I assume it can be inside the garage? (And why is there seemingly another connection "going around" that breaker? I don't understand what that part of the diagram signifies.)

Regarding the e-stop: Shouldn't the diagram depict the 12V e-stop signal feeding all four PW, as well as the stand-alone inverter? Or, is there some other (non-depicted) communication that will occur between the two PW+ (which the diagram depicts receiving the signal) and the other two PW and inverter (so everything would know to stop).

 

[wattsup]

There is no line of sight reason that I can see from my computer preventing them from doing your garage install.

Just curious then, what are all the “line of sight” discussions about in forums like this? The discussions usually seem to be in regards to disconnect switches and batteries.

 

[Vines]

Thanks very much @Vines.

Right, the main 125A breaker (right after the combo service panel) and the e-stop button, if both used, would completely de-energize all circuits in the building, and the PV modules.

Your service disconnect is inside the combo panel, on the exterior wall hopefully. This cuts grid power to the home.

Follow-up question: What code does the other 125A breaker (depicted between the Tesla gateway and distribution panel) satisfy? I assume it can be inside the garage? (And why is there seemingly another connection "going around" that breaker? I don't understand what that part of the diagram signifies.)

The Main breaker is to make the panel compliant with 240.21, so that all sources of power don't overload the (assumed 125A) bus and wiring of the existing panel. I do not know why the extra line geometry, which appears as a parallel connection around the added breaker only panel. Maybe @wwhitney would make sense of that.

Regarding the e-stop: Shouldn't the diagram depict the 12V e-stop signal feeding all four PW, as well as the stand-alone inverter? Or, is there some other (non-depicted) communication that will occur between the two PW+ (which the diagram depicts receiving the signal) and the other two PW and inverter (so everything would know to stop).

Often the E-stop wiring isn't detailed. As long as all the batteries and inverter get the message to shutdown then the system is compliant.

Just curious then, what are all the “line of sight” discussions about in forums like this? The discussions usually seem to be in regards to disconnect switches and batteries.

2020 NEC 706.15 requires that the Powerwall circuit be all of the following
1. Readily accessible
2. Within sight of the ESS or if impractical as close as practicable and there are marking requirements.
3. Lockable in the open position
4. For 1 and 2-family dwellings, a disconnecting means or its remote control shall be outside and readily;y accessible.

I cannot see your installation in my mind but all of our installations going forward have lockability at both the circuit breaker and at the powerwall disconnect on the unit.

 

[wwhitney]

(And why is there seemingly another connection "going around" that breaker? I don't understand what that part of the diagram signifies.)

My take is that line is a mistake and doesn't belong in the diagram.

As to the OP, I haven't reviewed the whole thread, but my first reaction is that Tesla may just be avoiding garage installs because in some jurisdictions they had problems with them. I.e. they may only want to do fast and easy installs, and so they may not want to take the time and effort to determine the details of what would be required to do a garage install in your jurisdiction, nor to trust that you have correctly done that work.

Cheers, Wayne

 

[Vines]

My take is that line is a mistake and doesn't belong in the diagram.

As to the OP, I haven't reviewed the whole thread, but my first reaction is that Tesla may just be avoiding garage installs because in some jurisdictions they had problems with them. I.e. they may only want to do fast and easy installs, and so they may not want to take the time and effort to determine the details of what would be required to do a garage install in your jurisdiction, nor to trust that you have correctly done that work.

Cheers, Wayne

Agreed on the extra line showing a parallel connection.

Garage ESS installs are certainly hard, and if you manage the customers expectations away from them there is much less risk. AHJ are changing the rules constantly around interior installations and spacing of ESS, that I don't blame Tesla for avoiding them.

Not everyone has access to wireless heat detectors, and so Tesla might be concerned that even though you installed something, the AHJ won't accept what you installed, or need additional interconnection. Some people think a Nest is good enough for heat detection.

Tesla wants to keep installs easy and they aren't setup to go much out of the box and risk having to re-do a bunch of work at final inspection.

 

[holeydonut]

...

2020 NEC 706.15 requires that the Powerwall circuit be all of the following
1. Readily accessible
2. Within sight of the ESS or if impractical as close as practicable and there are marking requirements.
3. Lockable in the open position
4. For 1 and 2-family dwellings, a disconnecting means or its remote control shall be outside and readily;y accessible.

I cannot see your installation in my mind but all of our installations going forward have lockability at both the circuit breaker and at the powerwall disconnect on the unit.

No blade disconnect for each powerwall?