AC Disconnect Label - 690.13(B) & 690.54

[Flapjack]

Does 690.13(B) & 690.54 only apply to the main PV disconnect, or does it apply to the main PV disconnect and any PV disconnect downstream of it? For example, a main PV disconnect comes off the supply-side of a service. Downstream there are a couple of AC combiner panels each with their own main breakers that have a number of branch circuit breakers to micro-inverters. Do the AC combiner panels need the "PV Disconnect" label per 690.13(B) and a label with the AC voltage and current per 690.54?

 

[Flapjack]

Bueller?

 

[jaggedben]

I think it's unclear and no one has thought much about it, which is why you're not getting opinions.

I think it's definitely one or the other, if not both. The code says 'each' but is unclear exactly what that means. So if all the PV outputs on the premises flow through one main disco, and you label that disco, perhaps that is 'the' PV disco and you don't have to label the individual inverter circuits. But alternatively if you label all the individual circuits perhaps you have labeled 'each' and don't have to label the main. If there a multiple main discos then you must label them all, at a minimum.

Personally I think it is good practice to label each micro-inverter branch because it helps identify circuits and because the outputs can vary and are not labeled on the equipment like with string inverters.

 

[pv_n00b]

Both 690.13(B) and 54 relate to a single point where the PV system interconnects. So to me that means you only need one label at the final PV disconnect.

 

[electrofelon]

Begin rant: I really hate most of these PV label requirement and their vagueness. What generally happens is labels are slapped on everything "just in case" because no one wants to chance failing an inspection, then they become kinda meaningless (not that they really serve much purpose in the first place IMO).

 

[jaggedben]

Begin rant: I really hate most of these PV label requirement and their vagueness. What generally happens is labels are slapped on everything "just in case" because no one wants to chance failing an inspection, then they become kinda meaningless (not that they really serve much purpose in the first place IMO).

I think most of the requirements are not as vague in the code as the one discussed in this thread. But since such a large number of installers and inspectors don't actually read the code, what you say ends up being true.

 

[electrofelon]

I think most of the requirements are not as vague in the code as the one discussed in this thread. But since such a large number of installers and inspectors don't actually read the code, what you say ends up being true.

Well it's also, IMO, PV is "over-labeled". I don't see what most of these labels accomplish. Like that stupid "the conductors of this system are ungrounded and may be energized" label. Or the PV source conductors label. A lot of it Just seems ridiculous and pointless if the inverters are UL 1741.

 

[pv_n00b]

Well it's also, IMO, PV is "over-labeled". I don't see what most of these labels accomplish. Like that stupid "the conductors of this system are ungrounded and may be energized" label. Or the PV source conductors label. A lot of it Just seems ridiculous and pointless if the inverters are UL 1741.

There was a popular joke at one time that manufacturers could not make inverters any smaller because the inverters required a minimum surface area to attach labels to.

 

[tallgirl]

Well it's also, IMO, PV is "over-labeled". I don't see what most of these labels accomplish. Like that stupid "the conductors of this system are ungrounded and may be energized" label. Or the PV source conductors label. A lot of it Just seems ridiculous and pointless if the inverters are UL 1741.

I agree, today. I disagree ages ago.

One day a nice firefighter came to my house and he had a boot in his hand because he was raising money for some group or another.

We got to talking and he admitted he'd never seen a PV system up close and personal. After having lived through Oncor deciding the breaker feeding the INSIDE of my house needed to be opened (instead of the one clearly marked as the disconnect) I realized people haven't a clue what any of those labels even mean. So, I offered to let him and some of his fellow firefighters come to my house and I'd educate them on what all those labels mean.

I'd bet beer money your average firefighter and utility worker knows a lot more than they all did 15 years ago.

 

[jaggedben]

I think the problem for firefighters is they can't possibly have enough time while responding to a fire to properly ponder the meaning of the labels, no matter how accurate and educational they might be when there's no adrenaline flowing. So keeping the labels to a small number of consistent requirements is better.

I'd even advance the idea that there be a distinction between labels for firefighters (rapid shutdown) and those for electricians (e.g. system output amps) and that the former be required to be on the outside of equipment and the latter be prohibited from the same.

 

[Carultch]

I'd even advance the idea that there be a distinction between labels for firefighters (rapid shutdown) and those for electricians (e.g. system output amps) and that the former be required to be on the outside of equipment and the latter be prohibited from the same.

"Good luck" getting manufacturers to give you the space available to mount anything on the inside of equipment. Or knowing in advance what space you have available so you can specify them to fit. I get that your giant 400A disconnects and panelboard doors will have plenty of space on the inside cover. But the typical string inverter, would likely not have enough space on the inside cover. It is hard enough finding space on the outside cover.

 

[jaggedben]

It's not really a serious idea codewise because it's just a bit too clunky all around. But the idea would only apply to equipment with an door over a deadfront (string inverters therefore not applicable) and I had in mind mainly panelboards not other equipment. At least I'll recommend it as a 'best practice.' Combined with getting rid of unnecessary labels it would hopefully make firefighters job easier.

 

[tallgirl]

I think the problem for firefighters is they can't possibly have enough time while responding to a fire to properly ponder the meaning of the labels, no matter how accurate and educational they might be when there's no adrenaline flowing. So keeping the labels to a small number of consistent requirements is better.

I'd even advance the idea that there be a distinction between labels for firefighters (rapid shutdown) and those for electricians (e.g. system output amps) and that the former be required to be on the outside of equipment and the latter be prohibited from the same.

Yes. Some of the "outside the panel, in the elements" labels are stupid.

I like the engraved "labels", but they are harder to get and more expensive. The vinyl labels with spaces and red ink (I hate red ink) are the dumbest thing ever to mount OUTSIDE a panel.