Would these be code violations?

[kolek]

I assume it is, but is it a code violation to run plastic conduit (containing PV wire) elevated by, say, fence posts?
Or all conduit must be buried from the PV array back to the house?
Is it allowable to have the PV array wires running exposed at any point, for example, under the roof of buildings on the way to the house?

2nd question.
I assume this is also a code violation, but can you put your conduit though a drainage pipe that runs under a small practically unused pubic road in the countryside in order to get your PV wires across said road? If not, how would you get your PV wires across a road? I can imagine this could potentially be a regulatory nightmare.

I know it depends on jurisdiction but just curious what generally the rules are in your neck of the woods.

 

[Luk88]

I'm no help regarding code in this instance.

2nd question.
I assume this is also a code violation, but can you put your conduit though a drainage pipe that runs under a small practically unused pubic road in the countryside in order to get your PV wires across said road?

Who owns the road? If you want to go "by the book" I think you need owners permission to put anything under (including in an existing drainage pipe).


You probably need someone with local knowledge to answer if you can put PV wires in an existing drain(properly protected).

If not, how would you get your PV wires across a road? I can imagine this could potentially be a regulatory nightmare.

Is the road asphalt? Concrete? Gravel? If the later I'd get the permission and I'd dig through it. Then I'd have to hire a compacting machine, otherwise there would be lots of spare road material.

If asphalt or concrete horizontal directional drilling is probably the best. No doubt there is a local company that does this in your neck of woods. Here is an example of a more diy approach:

This is how it looks in most places:

I know it depends on jurisdiction but just curious what generally the rules are in your neck of the woods.

Here I'd have to get owners permission in writing (even if I'm one of the owners) then it depends if it's a private, local government owned, county, region or national road. In this the easiest to deal with is private (whatever the owner is happy with), then the bigger the entity that owns it the more elaborate the rules.

Public entities usually work in accordance with some rules they either were given by the top level of gov. Or they just made them up by themselves. Sometimes if you ask thd right person they may just tell you what the rules are. However, most often if you ask the wrong person they will give you the worst "it cannot be done" kind of answer just to get rid of you. So in a way, before you ask you need to sort of know the answer already.

 

[kolek]

@Luk88 first thanks a lot for your detailed response!

Who owns the road?

City owns the road.
Nobody uses the road except the fire department who drives by once every 2 months doing their "routine check" of who knows what. I can totally see the fire truck stopping if they saw PV conduit using the drainage pipe, if for no other reason then it's the countryside where nothing ever happens and they are bored out of their mind. That plus using a public drainage pipe for passing a PV conduit probably violates something. I'm trying to research it here but also curious what the rules are elsewhere to get some sense of what to expect.

 

[mciholas]

High voltage DC in plastic conduit would be a serious safety hazard for someone who was not expecting it.

But 480 VAC would be okay? Why is that somehow "safer"?

Why would anyone expect to be able to touch energized wires in conduit just because the conduit is plastic?

Mike C.

 

[kolek]

Anyone know, generally is it a code violation to run plastic conduit (containing PV wire) elevated by, say, fence posts?
Or all conduit must be buried from the PV array back to the house?
I'm assuming all conduit from the PV array must be buried because that's what I see most people doing.

 

[wpns]

But 480 VAC would be okay? Why is that somehow "safer"?

Who said that?

 

[kolek]

You probably need someone with local knowledge to answer if you can put PV wires in an existing drain(properly protected).

I actually know a guy who does public works projects for the city so I'm planning on asking him and finding out the best person in the city to talk to. Was just curious what the rules are elsewhere before I go about that.

 

[dopeassjackson]

Who said that?

I believe they are arguing plastic vs metal.
Everyone seams to love plastic conduit..until they want to run DC into it. To me the PV voltage is basicly a un fused circuit and I would rather have it in plastic vs metal.

 

[DPC]

I believe they are arguing plastic vs metal.
Everyone seams to love plastic conduit..until they want to run DC into it. To me the PV voltage is basicly a un fused circuit and I would rather have it in plastic vs metal.

I struggle to understand it myself

Where a conduit system must cross a fire break I can see the need for metal

But as long as it’s done right I don’t have a reason to think pvc is not exceptable.

I’ve run unshieled 13.8 kv conductors through pvc between transformers and switch gear and received the blessing of the electrical authority.
They have to be comfortable with what you do…
If there is a rule that contravenes this the inspector is the one who ultimately has the final say if it exceptable for your specific installation

And they will tell you.
But ask first and don’t suprise them or they will as a knee jerk reaction to something un familiar no.

 

[mciholas]

Who said that?

The code book.

It says 480 VAC in plastic conduit is okay, but 480 VDC in plastic isn't (just picking some voltage).

Both are lethal if contacted while energized.

Why the difference? What makes plastic conduit acceptable for a 480 VAC circuit but not for 480 VDC?

The code requirement for metal conduit for DC circuits feels like something done for trade or business reasons, not the underlying safety issue.

Mike C.

 

[Luk88]

I believe they are arguing plastic vs metal.
Everyone seams to love plastic conduit..until they want to run DC into it. To me the PV voltage is basicly a un fused circuit and I would rather have it in plastic vs metal.

I didn't see anyone arguing...

I can't say above ground, but below ground (at least here in Poland/EU - can't say about anywhere else) it is perfectly fine to use plastic (so called RVL pipe) for both DC and AC as long as the wire it contains is adequate for the voltage and current. The only extra stipulation for DC is that the wire (not the conduit) needs double insulation and extra heat resistance.

I know it is allowed, because I put it on my drawing that was accepted by the utility.

Here is the type of conduit I'm talking about (80cm below grade):


Edit: In general I believe no above ground wiring is allowed here anymore (unless you're the utility etc). But don't quote me on that. It's just something I was told. So you can't get a permit to hang a cable above a road etc.

 

[kolek]

The only extra stipulation for DC is that the wire (not the conduit) needs double insulation and extra heat resistance.

Hey @Luk88 that's good to know. In this case the wire we're using is rated to be run directly exposed to the elements, it is double insulated outdoor wiring, and it's 1 gauge thicker than required for the distance, so whatever the city gov says is required, I think at least our cable will be ok in the conduit they specify. Thanks again for that info!

 

[tinyt]

The way I understand it when a wire carrying current breaks, at the moment it breaks an arc can be generated at the break and sustained depending upon the voltage between the break. The same is true if there is an insulation breakdown between conductors of opposite polarities. For DC, the arc will be sustained continously depending upon the length the break or insulation breakdown and voltage level. If the conductor is enclosed in plastic conduit, the sustained arc can make the plastic conduit catch fire. That is way metal conduit which will not catch fire is recommended for DC carrying conductors. And PV wires carry DC.

If the conductors in the conduit are carrying AC current, a generated arc gets extinguished at every zero crossing of the AC voltage and there is less chance of it being sustained long enough to make the plastic conduit catch fire.

I could be wrong, but that is the way I understand it.

 

[mciholas]

If the conductors in the conduit are carrying AC current, a generated arc gets extinguished at every zero crossing of the AC voltage and there is less chance of it being sustained long enough to make the plastic conduit catch fire.

AC can arc quite a long time as long as the ionized air remains in the path.

I could be wrong, but that is the way I understand it.

Your explanation makes some sense.

It does beg the question of why PV wire OUTSIDE the house can be PVC, though, if this is the issue in question. Why is outside safe in plastic and inside not?

The code often doesn't make sense.

Mike C.

 

[tinyt]

....


Your explanation makes some sense.

It does beg the question of why PV wire OUTSIDE the house can be PVC, though, if this is the issue in question. Why is outside safe in plastic and inside not?

The code often doesn't make sense.

Mike C.

I don't know much about the code maybe it is still not safe outside the house if there are surrounding materials that can catch fire. Is PVC enclosed PV wire on a house roof allowed by the code?

 

[Mike 134]

I actually know a guy who does public works projects for the city so I'm planning on asking him and finding out the best person in the city to talk to. Was just curious what the rules are elsewhere before I go about that.

please post his answer