Agreed, these are breaker locks in the thread, not LOTO kits.
Do you think the 2017 NEC requires ESS equipment disconnects to be lockable?
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Question about 120 percent NEC rule with Tesla Gateway 2
- Thread starter holeydonut
- Start date
Do you think the 2017 NEC requires ESS equipment disconnects to be lockable?
Lol ok- did the inspectors allow the breaker locks?
When my inspector was here I printed up an image with the breaker + lock that you posted. Contra Costa doesn’t recognize them for line of sight purposes.
As far as the last sentence above, that's certainly not true. 706.3's first sentence says "Wherever the requirements of other articles of this Code and Article 706 differ, the requirements of Article 706 shall apply." So if 706.xx had a statement of the form "such and such disconnect shall not be required to be lockable in the open position," then 706.3 would trump 705.22. But I don't see anything in 706 like that. Which means 705.22 still applies.
706.3's second sentence "If the ESS is capable of being operated in parallel with a primary source(s) of electricity, the requirements in 705.6, 705.12, 705.14, 705.16, 705.32, 705.40, 705.100, 705.143, and Part IV of Article 705 shall apply." I didn't chase down all those references, but my expectation is that those are rules that would be applying anyway, and 706.3 is just providing the pointers for reference. Regardless, that sentence at most expands a requirement to also cover ESSs that wouldn't be immediately obvious just from reading 705.xx; it doesn't take away any requirements.
Cheers, Wayne
For disconnects that are required by 705.22, they clearly comply: "The disconnecting means for ungrounded conductors shall consist of . . . or circuit breaker(s) that . . . (7) Be lockable in the open (off) position in accordance with 110.25."
But I'm not up on all the different requirements for disconnects, so I'm unclear if there's some other requirement for a different type of disconnect.
Cheers, Wayne
I read the different requirements in 706.3 to reference 706.7, where it talks about disconnects but does not talk about lockability.
In the end, I think I agree that the NEC does intend the ESS equipment disconenct to be lockable, same as the PV disconnect.
I do not think a lockable enclosure suffices, 705.22 (3) says it must be plainly visible whether it is in the on or off position. Locking the cover doesnt allow anyone to walk up and understand if the breaker is on or off.
Right, that's my point. The language in 706.3 means "unless there's a direct contradiction, comply with both 705.22 and 706.7." Since 706.7 doesn't say "the disconnect shall not be required to be lockable" (which would be a direct contradiction to 705.22), the lockability requirement of 705.22 still applies.
Cheers, Wayne
Garth Robertshaw (Contra Costa Sr Inspector) says the AHJ's get to set their interpretations, and the purpose of a line of sight disconnect is safety. Being said, using a LOTO clip or that integrated breaker thingie is not safe for line of sight purposes. So put some disconnects on the wall because that's all they'll approve for ESS when they're mounted in the garage. Garth didn't have any insights about bollards though.
Yep, he pulled out the serious code 2019 CEC 90.4 "Because I said so (paraphrased)"
Hi @Vines and @wwhitney ... QQ ... If I spec a system with 35 Enphase IQ7+ each with a 1.21A peak AC... this is 42.35A.
Assuming I need to connect an Enphase Envoy combining those 35 micros to a Generation Panel breaker... for this circuit do I need to use stranded #6 AWG THHN/THWN-2 or #8 AWG THHN/THWN-2 (conductor, neutral, and ground)?
And can someone run #6 or #8 through a 3/4" EMT conduit? Or will only #8 fit in 3/4" EMT?
Assuming I need to connect an Enphase Envoy combining those 35 micros to a Generation Panel breaker... for this circuit do I need to use stranded #6 AWG THHN/THWN-2 or #8 AWG THHN/THWN-2 (conductor, neutral, and ground)?
And can someone run #6 or #8 through a 3/4" EMT conduit? Or will only #8 fit in 3/4" EMT?
You can run your own numbers, if you want;
Conduit Fill Calculator | Southwire
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All the best,
BG
You can run your own numbers, if you want;
Conduit Fill Calculator | Southwire
Get accurate conduit fill percentages with Southwire's Conduit Fill Calculator. Perfect for electricians, engineers, and contractors.
All the best,
BG
That site is cool, but you know I trust vines and Wayne more than some online calculator heh.
Plus I can’t tell if 43A of PV Gen can go through #8 THHN/THWN2.
So, each IQ7+ must be protected by a 20A breaker, with a maximum of 13 units per breakers. But Enphase makes their combiner panel with a built-in Envoy for this purpose, which it sounds like you're planning to use.
That's could depend somewhat on where the Enphase combiner panel is located, what the ambient temperature is in that location, and what length of the circuit is exposed to that ambient temperature. But probably not:
Your minimum breaker size is 42.35 * 125% = 52.9A, which rounds up to 60A. You'll also need conductors with a 75C ampacity of at least 52.9A before temperature correction, and 42.35A after temperature correction.
Since the 75C ampacity of #8 Cu is 50A, you'll need to use #6 Cu or #4 Al (if the Enphase combiner panel has lugs rated for it). That will give you a 90C ampacity of 75A either way, so plenty of headroom for temperature correction, I expect that would be no problem (but still bears confirming with a computation).
Drop 2 microinverters, and now you can use #8 Cu on a 50A breaker, again assuming that 90C ampacity of 55A is sufficient after temperature correction. I.e. that the temperature correction factor is no smaller than 40/55 = 0.727, which means you'd be fine at a bit over 131F. There's something about a rooftop temperature adder, which I've never bothered to read but can be found here (310.15(B)(3)(c):
[Looks like it just requires you to keep the conduit spaced up off the roof at least 7/8" to avoid a big penalty.]
Cheers, Wayne
Blarg... ok I had an installer tell me that he couldn't add a new string of micros to my Enphase. Because it'd bring my total # of micros to 35, and he couldn't connect my Enphase Envoy to the Gateway 2 with the existing #8 THHN.
The thicker conductor meant he'd have to run new conduit to fit #6 THHN (he said he wouldn't force #6 through my existing 3/4 EMT. So, he couldn't do the project to add 12 more panels to my system because I clearly didn't understand the scope of the work to make a change to my existing system work.
He would be more than happy to add a second/new Enphase Envoy to my main service panel. But of course then the PV Gen wouldn't be metered and my Powerwalls wouldn't know to charge with their output.
Man I hate PG&E for having blocked me from upsizing my array during the initial install. So maddening.
If you add a second set of CTs to the new system, then the PW can charge from its solar production as long as the grid is up. Doesn't matter that it's in the main service panel. In fact, if you have two CTs on your existing solar, you could move one of them to the new system and reconfigure both of them as 2x in the PW since PV generation is balanced and you only really need one CT per system.
OK, just to be 100% clear, he could add 10 more panels to bring your total up to 33 while still using the #8 THWN-2 conductors (which is probably what you have, THHN is a common short hand, but it's an indoor only designation).
Cheers, Wayne
The guy wouldn't do the install with only 10 panels because he wouldn't make enough money to make this worth his while.
I guess my existing connector between the Envoy and the TEG2 is dual rated; it says THHN/THWN-2 on it.
Anyway, TLDR if you get an initial solar system that is undersized thinking you can add more solar to the existing system later... then you are an idiot. Even if PG&E forces you to a mini system... just figure out a way to get more panels up front. Don't be like Holeydonut (Holeydonut = loser).
Edit, also TLDR ... the 125% rule on continuous load for conductors is almost as bad as the 120% rule on busbars because both can stop an install in its tracks. Double-Blarg.
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Per 2017 NEC Informative Annex C, 3/4" EMT can take up to (4) #6 THWN-2 conductors.
Sounds like you need to find a less picky PV installer. Or else just pay this guy more.
Cheers, Wayne
Yeah, Enphase is reaching out to some more installers to see if any would do this. They agree the tough part isn't actually doing the racking/panels. The tough part is getting the 11x17 SLD created for the permit and dealing with PG&E. Maybe running a new conductor is required too... but that doesn't seem to be as difficult as these installers claim. They just don't want this job since easier solar installs are all flowing into every installer.
I've also explained to Enphase I am an idiot; cannot do this on my own. I think there's consensus I'm an idiot.
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