APPROVED CONDUIT

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construct

Senior Member
Wanted to throw this out there to get others take on this. (Inspectors and contractors alike) An electrical contractor in my jurisdiction has surface mounted rigid type 'L' 1/2" copper pipe and fittings used as conduit for branch circuit wiring to utilization equipment. I know different types of copper are used for LP gas, natural gas, and medical applications; but I have nerver found where it has been listed for use as a raceway. It is not being used as an egc, it is due to the desired appearance over EMT. My thought is that mechanical continuity cannot be maintained for bonding since pipe and fittings are simply pushed together, outside of the fact that I've not seen this attempted before.

Would appreciate hearing any thoughts. :?
 

iwire

Moderator
Staff member
Location
Massachusetts
Assuming it would fit the EC might be able to use a cable assembly in the copper tubing but it is a code violation to run single conductors in it.


300.3 Conductors.
(A) Single Conductors.
Single conductors specified in
Table 310.104(A) shall only be installed where part of a
recognized wiring method of Chapter 3.

Exception: Individual conductors shall be permitted
where installed as separate overhead conductors in accordance
with 225.6.

The copper tubing would have to be listed as EMT or another type of electrical conduit found in Chapter 3.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I have seen it done with black iron pipe as well.

I don't see it as really "bad", but code wise it is extremely dubious unless it is NM inside.

I am pretty sure there is brass conduit still made.
 
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dieselram752

Member
Location
mass
It sounds Hack but maybe.
If the fittings were soldered to keep a bond .
If the run was short.
If it was just covering a cable.
Still hack no mater how you look at it.
Copper water pipe is not an approved raceway so don't be shocked if it fails inspection.:ashamed1:
 

renosteinke

Senior Member
Location
NE Arkansas
I've seen even the strictest jurisdictions happily embrace the use of non-listed or unconventional raceway or conduit asemblies. The approval has come after I've explained the reasons for the use.

First, identify the reason you want to use a certain material, and outline your attempts to find a listed solution.

A starting point can be the UL "White Book." While the book might claim that, for example, there is listed conduit made of "miracle metal" or whatever material you wish to use, that doesnn't always mean you can buy it.

( I am thinking here of a pump manufacturer who needed some stainless RMC for a corrosive environment. While the UL provided a list of manufacturers, the electrical supply houses were not willing to supply it, and the manufacturers would only make it if the order was the equivalent of several freight-cars full. In the end, common stainless plumbing pipe was accepted by the AHJ).

The next step is to have a copy of some standard or specification. For example, the UL or ASTM standard for the product. Be prepared to show how your material meets or exceeds every requirement, save for the actual material. For example, is it as strong?

Show how the material you have chosen meets your requirements, while the usual product does not. For example, a certan plating shop in Chicago is able to use the (local law) expressly forbidden PVC conduit because any metal is quickly eaten through.

Finally, pay attention to the installation requirements. You might have to use additional supports, for example.

The biggest problems with using copper tubing as a conduit are the fabrication and the fittings. In detail:
1) Try bending it and it tends to collapse- not allowed;
2) The radius of the elbows is far too tight for wiring- you must be able to pull the wires; and,
3) Connections are not allowed to rely upon solder alone for mechanical strength.

So, what's one to do? Well, I once met the exact same problem - the desire to make the EMT fit in with the copper piping and other architectural details - using spray paint. There are metallic paints at the hardware store that are spot-on matches for copper, brass, whatever you want to use. In other situations, you can probably get away having the materials plated
 

iwire

Moderator
Staff member
Location
Massachusetts
Reno, putting all that personal stuff aside ........ is it an NEC violation to use single conductors in tubing that is not a chapter 3 wiring method?
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Reno, putting all that personal stuff aside ........ is it an NEC violation to use single conductors in tubing that is not a chapter 3 wiring method?

I would say it is a violation.

However, the code has no meaning unless it is enacted by some governmental entity and they always have built into the system a means by which you are allowed to request special permission to do something outside of the what the code specifically allows if you can convince the AHJ that you have a good enough reason.

So while the code itself does not allow for it, the enforcement mechanism does if you can make a good enough case with the AHJ.
 

iwire

Moderator
Staff member
Location
Massachusetts
I would say it is a violation.

However, the code has no meaning unless it is enacted by some governmental entity and they always have built into the system a means by which you are allowed to request special permission to do something outside of the what the code specifically allows if you can convince the AHJ that you have a good enough reason.

So while the code itself does not allow for it, the enforcement mechanism does if you can make a good enough case with the AHJ.

Yes.

But the OP is an inspector, he is asking about what a contractor is doing.

That being the case I assume the OP is looking for the code answer.

Now once the inspector gives the contractor the code answer the contractor could ask for 'special permission' but it is a request not a demand. The AHJ does not have to give special permission if they do not choose to regardless of the reason and if I am ever an AHJ I would be very, very hesitant to issue anyone written special permission.

The only reason for it in this case would be the looks of the installation, someone wants copper. To me that does not even rate a blip on the radar of special permission. For me special permission is used when there are no other options.
 

construct

Senior Member
Yes.

But the OP is an inspector, he is asking about what a contractor is doing.

That being the case I assume the OP is looking for the code answer.

Now once the inspector gives the contractor the code answer the contractor could ask for 'special permission' but it is a request not a demand. The AHJ does not have to give special permission if they do not choose to regardless of the reason and if I am ever an AHJ I would be very, very hesitant to issue anyone written special permission.

The only reason for it in this case would be the looks of the installation, someone wants copper. To me that does not even rate a blip on the radar of special permission. For me special permission is used when there are no other options.

Yes 'iwire', that is it in a nutshell.

Do I think this installation poses a safety hazard? No. Do I think it will effect the intended function of the circuit? No. Do I think this is the best asthetically pleasing choice? I don't know. But, these are all personal observations. My job is to require compliance with the code as written or amended, whether I agree or disagree with the requirements. When you start making allowances, exceptions, or special permissions, how far do you go.........where do you stop? When you step outside the boundaries of regulatory empowerment, I think you start making up your own rules. And I agree that special permission is used only when there are no other practical solutions. You can take my opinion with five dollars and buy a cup of coffee most anywhere.

I think this install is a code violation, but I wanted to be sure I was not over looking something. Thanks.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Yes 'iwire', that is it in a nutshell.

Do I think this installation poses a safety hazard? No. Do I think it will effect the intended function of the circuit? No. Do I think this is the best asthetically pleasing choice? I don't know. But, these are all personal observations. My job is to require compliance with the code as written or amended, whether I agree or disagree with the requirements. When you start making allowances, exceptions, or special permissions, how far do you go.........where do you stop? When you step outside the boundaries of regulatory empowerment, I think you start making up your own rules. And I agree that special permission is used only when there are no other practical solutions. You can take my opinion with five dollars and buy a cup of coffee most anywhere.

I think this install is a code violation, but I wanted to be sure I was not over looking something. Thanks.

IMO, the inspector is not the person to be making allowances, exceptions, or giving special permission.

However, the inspector is also human and may not recognize every code violation, or may miss it entirely. Sometimes being human has its place.

In this case, it does not appear like it would be all that hard to have run NM inside the copper, which would seem to be a code legal answer.
 
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construct

Senior Member
IMO, the inspector is not the person to be making allowances, exceptions, or giving special permission.

However, the inspector is also human and may not recognize every code violation, or may miss it entirely. Sometimes being human has its place.

In this case, it does not appear like it would be all that hard to have run NM inside the copper, which would seem to be a code legal answer.

I agree with you and I also miss things. I told the contractor IF I saw NM used, it would be compliant.
 
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