Question about 120 percent NEC rule with Tesla Gateway 2

[holeydonut]

I guess you can send your padlockable BRQLW's back... CoCo hit me with 706.7(E).

"Where energy storage system input and output terminals are more than 1.5 meters (5 feet) from connected equipment, or where the circuits from these terminals pass through a wall or partition, they shall comply with the following:"

And in this section is the requirement for a disconnect to be installed at the ESS equipment location.

They agree the BRQLW LOTO clip would satisfy 706.7(B). But they interpret Powerwalls in a garage and a Gateway outside to fall under 706.7(E). And in that application, you cannot use a BRQLW.

So the only time you can evoke 706.7(B) with a BRQLW is if the Gateway were inside of a huge garage but the Powerwalls were on the other end of the garage (but not in line of sight). In this application the fancy clip would be ok. Same goes if everything is installed outside and no wall is passed through.

Interestingly (I'm kidding; this isn't interesting at all), adding outdoor blade disconnects (one for each Powerwall) wouldn't matter for compliance under 706.7. So I'm not sure why Placer county is requiring that unique setup.

Fun times.

 

[wwhitney]

A bit new to 706.7, so my first question is why isn't the unit switch on each Powerwall sufficient for the 706.7 disconnect?

A 30A unfused pull out disconnect is quite compact and would certainly satisfy 706.7, I would think.

Cheers, Wayne

 

[Vines]

I guess you can send your padlockable BRQLW's back... CoCo hit me with 706.7(E).

"Where energy storage system input and output terminals are more than 1.5 meters (5 feet) from connected equipment, or where the circuits from these terminals pass through a wall or partition, they shall comply with the following:"

And in this section is the requirement for a disconnect to be installed at the ESS equipment location.

They agree the BRQLW LOTO clip would satisfy 706.7(B). But they interpret Powerwalls in a garage and a Gateway outside to fall under 706.7(E). And in that application, you cannot use a BRQLW.

So the only time you can evoke 706.7(B) with a BRQLW is if the Gateway were inside of a huge garage but the Powerwalls were on the other end of the garage (but not in line of sight). In this application the fancy clip would be ok. Same goes if everything is installed outside and no wall is passed through.

Interestingly (I'm kidding; this isn't interesting at all), adding outdoor blade disconnects (one for each Powerwall) wouldn't matter for compliance under 706.7. So I'm not sure why Placer county is requiring that unique setup.

Fun times.

Then throw the Tesla white paper out there, try to convince them.

 

[Vines]

Basically the enable switch on the PW triggers an internal relay that does disconnect all current carrying conductors.

 

[wwhitney]

Is that Tesla white paper publicly available?

Cheers, Wayne

 

[holeydonut]

I jokingly said there are power switches were on the units, but he said those switches didn't look like "disconnects." I guess these inspector guys don't like jokes.

Sunrun's guy didn't really offer much info. He literally thought he could just tell the inspector to approve things after looking again (that approach didn't work). Anyway, they need to go see if it's better to put some small pull-out disconnects or knobs, or to install a new subpanel. Either way it's work that someone needs to pay for, and I'm thinking they may pass the buck to me on this.

 

[charlesj]

I feel for you guys with all this trouble. I had none of this with TEG and PW in garage.

 

[miimura]

I feel for you guys with all this trouble. I had none of this with TEG and PW in garage.

Everything (meter, main panel, gateway, generation panel, powerwalls) mounted on an outside wall within sight of each other is by far the least hassle.

 

[holeydonut]

Everything (meter, main panel, gateway, generation panel, powerwalls) mounted on an outside wall within sight of each other is by far the least hassle.

Technically it all has to be within 5 feet of each other or you’ve lost “line of sight”. And since Powerwalls have a minimum safe separation distance, it’ll be tough to fit it all in one contiguous 5 foot piece of wall.

I thought my garage was ideal since it has one big long wall and no windows. But I couldn’t fit 3x Powerwalls and all PV/ESS equipment within 5 feet of one another. That's why I have my Powerwalls on the inside part of the wall and all the other equipment on the same wall but on the outside.

 

[Vines]

Is that Tesla white paper publicly available?

Cheers, Wayne

The white paper is not available publicly, so unfortunately I cannot share it. Sunrun has a copy though I am sure.

 

[holeydonut]

The white paper is not available publicly, so unfortunately I cannot share it. Sunrun has a copy though I am sure.

In July I got a call from Sunrun's Powerwall Expert where he said "What's a Gateway 2?". I don't think Tesla has sent anything useful to Sunrun...

 

[miimura]

Technically it all has to be within 5 feet of each other or you’ve lost “line of sight”. And since Powerwalls have a minimum safe separation distance, it’ll be tough to fit it all in one contiguous 5 foot piece of wall.

I thought my garage was ideal since it has one big long wall and no windows. But I couldn’t fit 3x Powerwalls and all PV/ESS equipment within 5 feet of one another. That's why I have my Powerwalls on the inside part of the wall and all the other equipment on the same wall but on the outside.

Where does the 5 feet rule come from? It doesn't make sense to me. However, I know better than to think that everything in NEC and AHJ judgement has to actually make sense.

 

[holeydonut]

Where does the 5 feet rule come from? It doesn't make sense to me. However, I know better than to think that everything in NEC and AHJ judgement has to actually make sense.

It's in the 706.7 (E) I got hosed with today.

"Where energy storage system input and output terminals are more than 1.5 meters (5 feet) from connected equipment, or where the circuits from these terminals pass through a wall or partition, they shall comply with the following:"

You know it's funny... the FAA has not defined visual line of sight (VLOS) to be a discrete distance since there are too many factors in play to properly isolate VLOS. But the NEC thinks 5 feet sounds about right.

 

[holeydonut]

Just got off the phone with Sunrun - and one thing came up that I cannot quite pin down is "who is supposed to be the one that gets this right?"


The County permitting office is just supposed to approve work to begin and collect money. They don't judge if a permit would be code compliant or not.

The County inspector's job is to say something was done incorrectly and only pass things they deem to be done correctly.

Sunrun's operations/branch team is just supposed to implement and install something as designed.

Sunrun's sales team is supposed to get people to sign a contract.

I've been told it is 100% against protocol for a homeowner to provide approval before a site plan, scope of work, or line diagram before it is sent in for permitting.

PG&E's job is to just fight this as much as possible so they keep their monopoly profit. I know their role in all this.

So who exactly is it that is tasked to do things "right"? This is maddening. Is it the engineer who puts his name/signature and CA license number on the line diagram? Because that person has never bothered once to contact me or the installation crew. And this person has never actually looked at my freaking house. So how is that person supposed to get this "right" if they literally have the least amount of information?

At some point Sunrun is going to demand I chip in more money to pay for all these permits, revisions, panels, and switches. And I wonder who I'm supposed to be blaming for not having all the requisite data to do this "right".

 

[wwhitney]

The AHJ is supposed to be clear ahead of time on what the requirements are, and provide notice of the written codes in force. Sunrun has had the opportunity to know about the 2019 California Electrical Code requirements since they were published July 1, 2019, and should know that they have been in force since January 1, 2020.

Sunrun is supposed to design and submit plans for an install that is compliant with those written codes. The final responsibility is on them, even when others fail to do what they are supposed to do.

The plans examiner is supposed to review those plans and point out errors, but has no liability if they miss an error. Failure to enforce part of the 2019 CEC (previously or presently) does not exempt projects from compliance.

The inspector is supposed to check that the install meets the written codes (and in some cases, matches the approved plans) but has no liability if they miss an error. Failure to enforce part of the 2019 CEC (previously or presently) does not exempt projects from compliance.

When the inspector makes up a requirement not in the written codes, or the AHJ tries to change the codes in force after a project is permitted, those actions should be fought and overturned (to the extent economically viable by the affected parties). It can be a fine line between an unreasonable interpretation of certain language, and a reasonable if unusual interpretation.

Cheers, Wayne

 

[wwhitney]

P.S. With respect to 706.7, the best route forward is for Sunrun to convince the AHJ that the unit switch on each Powerwall satisfies the disconnect requirement. Perhaps with the assistance of the non-public white paper from Tesla referred to earlier. Or if Sunrun is incompetent and you want to pick up the slack, rather than wait or have extra disconnects, for you to so convince the AHJ.

Cheers, Wayne

 

[holeydonut]

I recall the cantankerous lineman told you that. Has anyone else from PG&E given you that attitude, or just this one fellow?

Cheers, Wayne

FWIW Wayne - I got a call from that T-Man's supervisor today. He said I was in the wrong; Sunrun was in the wrong; and the PG&E planning office (Diablo) did "not do their homework" so the Planning office was wrong too.

The supervisor re-iterated that if he himself were out at my house that day, he would have shut everything down because the riser cannot be within 36 inches of the main panel even under like for like since a solar + ESS project was involved. Basically if you want to go green, you better be prepared to spend a boatload of money to do it "right". It's PG&E's job to make sure things are done "right".

So, I think it's actually a lot of people at PG&E who do not want customers going green unless they jump through every hoop imaginable. If PG&E can burden the project, they will.

 

[holeydonut]

P.S. With respect to 706.7, the best route forward is for Sunrun to convince the AHJ that the unit switch on each Powerwall satisfies the disconnect requirement. Perhaps with the assistance of the non-public white paper from Tesla referred to earlier. Or if Sunrun is incompetent and you want to pick up the slack, rather than wait or have extra disconnects, for you to so convince the AHJ.

Cheers, Wayne

I'm going with option 2 (edit, sorry I said option 1 before), and adding option 3 haha.

I told Sunrun their own agents turned DOWN the drawing I showed earlier in this thread. Remember back then, I didn't want a scary Quad 30A so I had a redundant generation panel inside. The Gateway and Enphase 3C were outside. This means both inside and outside, there were ESS and PV breakers.

I asked Sunrun to install this the day they were out here and even provided the 125A panel, handful of two pole 30 A breakers, and a 125 A two pole breaker.

They rejected this and instead went with that option with the Quad 30 A. So I'm telling them it's their fault they didn't just do the redundant option when all their expensive electricians and installation crew was already in my home doing all the work.

 

[holeydonut]

When the inspector makes up a requirement not in the written codes, or the AHJ tries to change the codes in force after a project is permitted, those actions should be fought and overturned (to the extent economically viable by the affected parties). It can be a fine line between an unreasonable interpretation of certain language, and a reasonable if unusual interpretation.

CoCo responded to me that the "enable" switch on the Powerwall 2 does not qualify as a "disconnecting means" under 706.7.

The only useful data nugget I have today is that the toggle on the side of the Powerwall 2 is not sufficient; even if the switch accomplishes the described requirements of 706.7. Tesla wants to call this toggle an "enable" switch, but the inspectors think it's an "on/off" switch. That subtle distinction seems to be the issue.

I guess I'm not the first homeowner to have this problem out here. The County, fire AHJ, and Tesla apparently already tried to sort this out. And CoCo disagrees with Tesla's whitepaper/argument that the "enable" switch is a satisfactory "disconnecting means". I don't know if this disagreement is due to the appearance, operability, or functionality of that "enable" switch. But it simply isn't sufficient.

And to your point; the CRC, NEC, etc don't seem to have text describing this interpretation. It's a thing Sunrun learned on their own now since it was also not communicated at the time of the permit approval. But the County is now requiring Sunrun to go back and add some other disconnecting means in line of sight of the Powerwalls that they would be comfortable with.

 

[wwhitney]

CoCo responded to me that the "enable" switch on the Powerwall 2 does not qualify as a "disconnecting means" under 706.7.

Sounds like a bad call to me, assuming the switch demonstrably disconnects the Powerwall from all ungrounded conductors, as I presume Tesla's white paper confirms that it does. 706.7 doesn't have any other requirements for the disconnecting means, like being lockable, nor does it opine on what is and isn't allowable.

On the other hand, 706.7 doesn't have any language like 422.34 on "unit switches as disconnecting means." So their interpretation seems defensible and installations going forward will have to comply with it in your jurisdiction.

Subtleties like this get worked out as they arise, and this is just a sign that Powerwalls are still in the early adopter phase (even though I got mine 2.5 years ago, when the 2014 NEC was in force in California, and inspection was a breeze.)

Cheers, Wayne