Maybe to reduce the likelihood of this scenario: electrical worker mistakes DC conductor for an AC conductor. Tests for voltage with an AC voltmeter, but it reads 0 because there is only DC (is this correct)? Gets shocked as a result.
If there is a fault there is a concern that the peanut butter will mix with the chocolate. We don't want DC on the AC conductors and vice versa in the event of a cross conductor fault since the protection system have different ratings.
I don't find that argument to make any sense. Couldn't the same thing be said of AC+AC conductors? Say small and large AC conductors in the same conduit or raceway or box? I could have some 12 gauge conductors in a circuit with some big feeder conductors and there's no restriction, and if there is a cross fault that big circuit could turn those 12 gauge conductors into chowder.
Even if the DC is non-PV? You certainly seem to work with more AHJs that ignore what the code explicitly permit than most do.
Yeah I don't really see the reason to allow 600V AC in the same conduit as 120V AC circuits, but not 600V DC. Either of the 600V sources is going to wreak a lot of havoc if it gets onto the 120V circuit.
The main one who said that was CPS in San Antonio; they have their rules and they do not explain every one of them.
No, the exception is broader. Multiconductor jacketed cables for remote control, signaling, etc are also permitted. But also, even without the exception, the main text of 690.31(B)(1) only restricts non-PV system ckts unless they are separated by a barrier or partition. But I cannot find in the code what is a barrier or partition. A barrier can be electrical tape in my mind. When you open the Sol-Ark or any inverter, there generally are not any strict barriers or partitions in the wiring compartment. Everything is separated by space and orientation, and in some cases not much space at all, or maybe even some wiring is touching. The code needs to change with reality, it is safer to install wiring methods that keep the wiring neat and protected, and a trough often helps with that. I put DC battery circuits in their too, because the inverter manufacturers place conduit openings that make it difficult not to. If you use a gutter for a few ckts, you almost have to do bring all into it. You can still arrange and bundle conductors in the trough to keep physical separation and order.
Ok so I guess the battery output could be a "PV system circuit". So are "grid" and "load" both inverter output circuit?
I think these are rapidly becoming more common. For people having a PV system installed, for not a lot more money you can have battery backup for cheaper than a generator install.
I have certainly met all types among inspectors. It does not matter if the AHJ is generally green friendly, some inspectors still go by the book, while others don't know the book or don't care. This is a fine enough point that I'm not surprised if most inspectors don't catch it, but it's also a well known enough one that it's gonna limit Sol-Ark's market like you said.
Yes, both are inverter output circuits, because the Sol-Ark (or Schneider) inverter will output energy on either depending on how it is programmed and how large loads are.
There are a lot of restrictions in the NEC around mixing AC conductors, it's not a free for all. The issue with mixing AC and DC does not have to make sense to either of us, it just has to makes sense to enough people on the CMP to vote it in. Unless you are on the CMP they don't really care that much about what either of us think is sensible.
Since it does not state it plainly in the NEC it leaves us to speculate, and one speculation I have provided is that they don't want the AC and DC to cross in a fault. Prove me wrong, a letter from a CMP 4 member will suffice.
My people will get working on it.
. Ok well fair enough as I did ask, "any idea what THEY think the issue might be?" Not "is there any technical justification for this?". Your response did seem more like the latter however.You can tilt at AHJ windmills all you want, but my track record of winning those fights isn't very good, even when their rules were not supported by the NEC. Most of the time compliance hasn't been that big of a deal; I choose my battles accordingly.My people will get working on it.
Ok so you are going with the ggunn approach:
"it doesn't have to make sense, we just have to comply"
Btw just want to be clear I meant that in jest. I mean yes in the end it really all boils to what the AHJ/inspector allows + any fighting/appeals if deemed worth it, but sometimes it's nice to talk about the theory, question if perhaps there is a reason that I didn't see - or just complain about the CMP's
