Under the NEC or Not?

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Little Bill

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Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I got called to correct some things on a failed inspection, actually two failed inspections. The building in question is a barn on a "Pot-belley" pig sanctuary/farm. I won't get into the other red tagged items but just the one concerning a solar panel.

The owner installed a solar powered fan. It is actually an attic fan but they installed it in the side/gable of the barn. It is a packaged product that includes a solar panel, wire, and the fan. It is only a 12V DC fan. It is run straight from the solar panel, no inverter, battery or anything. It has push-in connectors for the hot (+) and gnd. (-) on each end of the wire.
The inspector turned it down and just wrote on his rejection paper- "solar array needs to be installed according to the NEC". I called him and asked what he wanted. He said the wire from the solar panel needed to be in rigid conduit down to a OCPD and disconnect.
Then from the disc. to the fan in MC.

Now I'll be first to admit that I don't know hardly anything about solar panel installs. But since this came as a packaged unit and in no way ties into the electrical for the barn, I don't understand why the inspector would even be inspecting it. It is only 12V DC, and from what I understand, if under 30V it wouldn't have to be in conduit or an OCPD. I may be wrong on that but not for sure.
I ask him what he wanted for an OCPD/disconnect since it was DC. I don't know of anything but an in-line fuse or a fuse block, but he said that would be field engineering and not approved. I don't know what he wants since there is nothing I can find locally that would satisfy him. I can't find anything in the code that says rigid, just metal raceway. Also, wouldn't the push-in connectors be a disconnect?

I told they owner the best thing they could do is just remove the fan and let the inspector just check the other items I fixed. Then it would be up to them to take care of the fan later if they still want it.

Here are a few pics of the solar panel, wire, and fan.

0619121101.jpg


0619121101a.jpg


0619121101b.jpg
 

Little Bill

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Location
Tennessee NEC:2017
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Semi-Retired Electrician
Sounds absurd. Is the fan listed?

The owner didn't have anything (paperwork) for the unit. I couldn't see anything on the fan, and I couldn't get see anything on the panel from where I was looking at it off the ladder. I didn't climb up on the roof to look at the other side.
That was one reason I told them it would be best to just remove it. If the unit isn't listed he probably wouldn't accept what ever I did to it. It would probably cost more to make it comply than what they paid for it.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
don't think it meets:

690.1 Scope. The provisions of this article apply to solar
photovoltaic (PV) electrical energy systems, including the
array circuit(s), inverter(s), and controller(s) for such systems.
[See Figure 690.1(A) and Figure 690.1(B).]
 

iwire

Moderator
Staff member
Location
Massachusetts
A new gray area.

Most of us accept if we bring a listed generator to a property and connect it permenantly to electrical equipment in a building the NEC would apply so why don't you think it applies here?
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
A new gray area.

Most of us accept if we bring a listed generator to a property and connect it permenantly to electrical equipment in a building the NEC would apply so why don't you think it applies here?

I don't think it is gray. I don't think it falls under the scope.

Do any other articles use figures to explain what is covered?
 

iwire

Moderator
Staff member
Location
Massachusetts
I don't think it is gray. I don't think it falls under the scope.

Do any other articles use figures to explain what is covered?

How is it not premise wiring?

Can I permently wire the same type of listed fan with rubber cord stapled to the building out to a listed generator?

And I don't see how the scope you posted excludes the PV portion of this set up.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
How is it not premise wiring?

Can I permently wire the same type of listed fan with rubber cord stapled to the building out to a listed generator?

And I don't see how the scope you posted excludes the PV portion of this set up.

It is premise wiring. Just don't see it in these two figures.

690.1(A).JPG

690.1(B).JPG
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
A new gray area.

Most of us accept if we bring a listed generator to a property and connect it permenantly to electrical equipment in a building the NEC would apply so why don't you think it applies here?

So how would you make the install comply? What would you use for OCPD and disconnect? The inspector didn't want the rigid ran into the solar panel, just close to it, then add a bushing on the end and seal it. The rigid would then run inside to a disconnect with OCP.
Then from the disconnect to the fan using MC cable. If you use MC you would have to cut the wire, thus voiding the mfg. listing (if there is one).
I also can't find in the NEC where it states "rigid" must be used. All I see is "metal raceway."
I personally don't think the inspector knows anymore than I do about PV systems, which in my case is little to none.:happysad:
That is why I said to ditch the fan!
 

jim dungar

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Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
According to the OP, the fan runs on DC directly from the solar array. Everything I see in the scope of 690, involves an inverter to AC.
 

jxofaltrds

Inspector Mike®
Location
Mike P. Columbus Ohio
Occupation
ESI, PI, RBO
So how would you make the install comply? What would you use for OCPD and disconnect? The inspector didn't want the rigid ran into the solar panel, just close to it, then add a bushing on the end and seal it. The rigid would then run inside to a disconnect with OCP.
Then from the disconnect to the fan using MC cable. If you use MC you would have to cut the wire, thus voiding the mfg. listing (if there is one).
I also can't find in the NEC where it states "rigid" must be used. All I see is "metal raceway."
I personally don't think the inspector knows anymore than I do about PV systems, which in my case is little to none.:happysad:
That is why I said to ditch the fan!

Don't know about Tenn. but in Ohio an inspector MUST cite what he is failing you on. Not just it's in the book or article 690.

Like 690.4(F). That way you know what you have to fix.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Don't know about Tenn. but in Ohio an inspector MUST cite what he is failing you on. Not just it's in the book or article 690.

Like 690.4(F). That way you know what you have to fix.

I actually haven't been failed. I got called into this because they had two failed inspections. They had two different electricians (maybe electricians) that wired the barn. After the second one the owner decided to get some recommendations for electricians from another source. That's when I was called in. I read the inspectors list and had no trouble finding/fixing the other items but when I came to the PV part, all he said was " solar needs to be wired according to the NEC". I called him and he wasn't specific about much other than the use of rigid and MC. He couldn't tell me what he wanted for OCP or disconnect.


How come no one has asked about the "critters"?
 
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jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Let's suppose for a second that this is under the NEC (and is not a listed, self contained device). All of the inspector's requests are STILL RIDICULOUS.

1) Raceway is not required for source circuits under 30V. 690.31(A). The only thing he's got is 690.31(E), and that is only inside the building.
2) RMC has never been required. EMT has always been allowed in 690, and the last couple iterations of the code have allowed other raceways and methods as well.
3) Overcurrent protection is not required for this setup regardless of voltage. See the exceptions in 690.9(A).
Those exceptions are there to recognize that overcurrent protection is patently ridiculous for this setup, because the panel cannot produce more current than the fan uses.
4) Disconnecting means are required specifically to 'disconnect conductors of the PV system from all other conductors in a building or other structure.' 690.13 Since the conductors of this device are not connected to any others, no disconnect is necessary.

The most you would have to do to make this compliant is to put the wire inside the building in a raceway, e.g. EMT. It might be easer to just move the wire from the inside to the outside. :-D The inspector needs an education on 690. If he's using the NEC as his standard, hold him to the NEC.
 
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Little Bill

Moderator
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Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Let's suppose for a second that this is under the NEC (and is not a listed, self contained device). All of the inspector's requests are STILL RIDICULOUS.

1) Raceway is not required for source circuits under 30V. 690.31(A). The only thing he's got is 690.31(E), and that is only inside the building.
2) RMC has never been required. EMT has always been allowed in 690, and the last couple iterations of the code have allowed other raceways and methods as well.
3) Overcurrent protection is not required for this setup regardless of voltage. See the exceptions in 690.9(A).
Those exceptions are there to recognize that overcurrent protection is patently ridiculous for this setup, because the panel cannot produce more current than the fan uses.
4) Disconnecting means are required specifically to 'disconnect conductors of the PV system from all other conductors in a building or other structure.' 690.13 Since the conductors of this device are not connected to any others, no disconnect is necessary.

The most you would have to do to make this compliant is to put the wire inside the building in a raceway, e.g. EMT. It might be easer to just move the wire from the inside to the outside. :-D The inspector needs an education on 690. If he's using the NEC as his standard, hold him to the NEC.

Thanks Jag, I was hoping someone familiar with solar installs would chime in. I found a couple of the sections you cited but I'm not knowledgeable enough of this area to be sure.
I have no problem fixing/changing things required by an inspector when he can show me specifically what he wants with code sections to back it up, and I feel confident he knows what he is talking about. It was painfully obvious from talking to him that he didn't know/understand the solar (PV) section of the code. I think this was something he had never ran into and rather than search it out on his own, he just failed it. Then only saying, "do it according to the NEC".
 

iwire

Moderator
Staff member
Location
Massachusetts
According to the OP, the fan runs on DC directly from the solar array. Everything I see in the scope of 690, involves an inverter to AC.

Which is why I say we are entering a gray area. As I understand it the idea of metal conduit and or outdoor disconnect is the protection of firefighters.

Now I think we can all agree this tiny system does not pose much of a danger but at what point would you say it does? How large of a 'plug and play' PV system should we be able to install without the NEC applying?

What should be the max voltage?

What should be the max short circuit current?


I really do not know if the inspector is right or not, all I am saying is that I don't think it as anywhere near as cut and dry as some seem to. I think the biggest issue is that it is a surprising idea and therefore dismissed without thought.
 
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