Two NEC 2017 code questions for Sol-Ark 15K: Wireways and conduit sizes

[EnergizerNate]

Background:

This is my first post to this forum. I have been designing a dual Sol-Ark 15K system for my new property since last fall and I am working through the last few details that are bugging me. I am located in Ohio under NEC 2017 and plan to be grid-tied with net metering to start, eventually headed to an off-grid setup in several years (hence the dual 15Ks). The AHJ said I can DIY solar as long as I have stamped electrical plans (still in work, my first draft is done, need to do a second pass).

Question 1:

AC and DC in the same wireway. I see it all the time on YouTube and this forum where people install a wireway under their Sol-Arks. Referring to the NEC 2017 code, this section bugs me when it comes do doing a wireway with PV, battery, and AC circuits all in the same wireway. My interpretation is in the code below so you can see why I am stuck on this.

NEC 2017 - 690.31 (B)

(B) Identification and Grouping. PV source circuits and PV output circuits (wires from my panels?) shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems (the grid input? a generator input?), or inverter output circuits (Sol-Ark Load?), unless the conductors of the different systems are separated by a partition.

Has anyone under NEC 2017 had an inspection done and had success or problems with this? I would hate to install a wireway and find out I had to change it. I have emailed the AHJ on this, but haven't received a response. Also emailed someone who does Sol-Ark installs and haven't received a response.

Background for Question 2:

I will only be installing 1 of the 2 Sol-Ark 15s in Phase 1 of my project. The 2nd will come when I have made the final decision to go off-grid. Thus, I will be wiring my 200A utility service into a single Sol-Ark, and feeding my 200A breaker panel out of the single Sol-Ark in Phase 1 (in general terms). So I will need 4/0 AL wire, which will either be SER cable or individual 4/0 wires to handle 200A.

Question 2:

The Sol-Ark 15K has 1.5" trade size knockouts. Assuming THHN or THWN-2 wire, this only handles 2 wires (EMT) or 1 wire (FMC) at 4/0. I could go to copper 200A conductors at 2/0, but then I am at 3 wires (EMT or FMC) and that still leaves me hanging if I need to bring in 2 hots, a neutral, and a ground. If I bring in an 4/0 SER cable, I need a 2" knockout for the connector. 2" knockouts would be better since that size allows four 4/0 conductors.

How do other people meet conduit fill code with the 1.5" knockouts? I would like to just enlarge the LOAD and GRID knockout holes to 2" or make new ones if there is room. I have a hydraulic punch I could use to do this. Need to ask Sol-Ark if this voids the warranty.

Tangent: Looking at FMC conduit if a wireway doesn't work out and also because I can't find a cheap conduit bender for 1.5 - 2" EMT. I might try something with lots of LBs so I can use EMT or IMC without needing to bend it.

Summary:

As you can tell, I want to make sure I can answer every part of the code when I get inspected because I don't want any expensive re-work. I am replacing my electrical panel soon as part of this project and hope to ask my AHJ some questions and get a feel for their strictness during that inspection, but I would appreciate any advice on these two items.

 

[Sol Goodman]

I used a 2" knockout cutter and enlarged one of the holes so I could get a 2" TA in there. I, unfortunately, did not think to check with Sol Ark about the warranty question. OOps. Hope that doesn't bite me in the ass someday.

 

[DIYrich]

Q1: partition the ac from dc. May be easier to have separate wire ways.

Q2: isn't there separate knock outs for each connection? Put a busbar in the wire way to make it easier to install #2

 

[byteharmony]

Q1: Watched many videos and not a single one had separate wireways. The sol ark device itself has all the different types of power wires in the same air space, why should an air space 2 feet further away be a problem. I get your read of the code. For me it's like having ground only bonded at the 1st panel. it makes a bigger difference the further you get from the junctions.

Q2: For 0/4 you could consider using the gen port for passing neutral wires and the com port for the ground. For SER cable you could consider separating the conductors in the wireway and passing the individual wires through the EMT / FMC into the sol ark - Is that a code issue?

Southwire fill calculator shows you get 2 4/0 aluminum in 1.5 FMC without a problem.

 

[Zapper77]

Background:

NEC 2017 - 690.31 (B)

(B) Identification and Grouping. PV source circuits and PV output circuits (wires from my panels?) shall not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as conductors, feeders, branch circuits of other non-PV systems (the grid input? a generator input?), or inverter output circuits (Sol-Ark Load?), unless the conductors of the different systems are separated by a partition.
.

What did you end up using?

I told my inspector, "these are for the same system". That almost worked.

We compromised on using 1 1/2" flex conduit around grid and load inside the wire way. He implied that, what I do after he leaves is on me. The next rewire I did, that stuff came out.

 

[EnergizerNate]

What did you end up using?

I told my inspector, "these are for the same system". That almost worked.

We compromised on using 1 1/2" flex conduit around grid and load inside the wire way. He implied that, what I do after he leaves is on me. The next rewire I did, that stuff came out.

Well, I know I will get a good ribbing for it, but my entire setup will be using FMC and not a large wireway. Partly because of this code requirement and partly due to height limitations actually. I am building right now, so I hope it all works. I think in the 2020 or 2023 code they changed it because most inverters have AC and DC so close together anyway.

 

[ChrisG]

What did you end up using?

I told my inspector, "these are for the same system". That almost worked.

We compromised on using 1 1/2" flex conduit around grid and load inside the wire way. He implied that, what I do after he leaves is on me. The next rewire I did, that stuff came out.

Do you have a picture of this @Zapper77? I’d like to see that flex inside wire way and how you entered/exited with it. Odd they would let you have a horizontal partition in the wireway.

 

[Zapper77]

Do you have a picture of this @Zapper77? I’d like to see that flex inside wire way and how you entered/exited with it. Odd they would let you have a horizontal partition in the wireway.

It's a large wire cabinet under the inverter.

 

[Zapper77]

 

[ChrisG]

View attachment 176244

Nice. So you removed the flex conduit already?

 

[Zapper77]

Nice. So you removed the flex conduit already?

Yes.

Inspector did say he would be ok if I bring the AC THHN cables in from the top right side without flex conduit. But I already punched the 2" hole in the left side.

Basically he didn't want the AC and DC cable to cross unless I had a barrier between them.

 

[Quattrohead]

Basically he didn't want the AC and DC cable to cross unless I had a barrier between them.

Surely that does not matter if all the wires are rated to the highest voltage they will see, I think most are rated to 600 volts.
I am pretty sure this is the only thing that code looks for in this instance.

 

[Zapper77]

Surely that does not matter if all the wires are rated to the highest voltage they will see, I think most are rated to 600 volts.
I am pretty sure this is the only thing that code looks for in this instance.

It was easier to please the old man. I literally shoved THE 4-6AWG THWN into a 1" flex conduit. Once he signed off on the work and left I took them out.

 

[prometheanfire]

Newer NEC rules say that as long as all insulation is great than the max system voltage you are good. May not satisfy them as they are going off of NEC 2017, but some may be ok with going with newer code...

Digital Codes

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org

NEC 2023 300.3 C 1

 

[Zapper77]

Newer NEC rules say that as long as all insulation is great than the max system voltage you are good. May not satisfy them as they are going off of NEC 2017, but some may be ok with going with newer code...

Digital Codes

ICC Digital Codes is the largest provider of model codes, custom codes and standards used worldwide to construct safe, sustainable, affordable and resilient structures.

codes.iccsafe.org

NEC 2023 300.3 C 1

My area is still going off of 2017.

 

[Balrog006]

FWIW these are my takes from my self installed 15k on NEC 2017

Q1 AC and DC can occupy the same wireway/enclosure as long as nothing exceeds 600v and they are part of the same system. That being fed into the 15k is all part of the system so DV PV and AC load wiring are good to go. Just don’t try to run wiring from other circuits or something back thru the wireway from a panel to a sub panel or something like that-those are not part of the system.

Q2 I tried and could not get 3+ 4/0 AL (L1, L2, N +Ground) conductors in the 1.5” MC nipples between my wireway and the inverter. I had to bite the bullet and get some 3/0 copper and the. I could just fit the 3 mains in each nipple-the ground I ran in another knockout, the comms or whatever was close and had space.

Regardless code fill limitations for conduit size vs cable do not apply to short nipples, iirc 6” or less long.


Happy building!