Support column as electrical raceway?

[Slowbuilder]

Hey Sparkies!!

I have an outdoor shade structure that sits on a concrete slab and has a frame of 3" galvanized pipe with a corrugated tin roof. The pipes are structural, open at the ends, and bolted together to form the frame. I have power on one side of the structure, and I would like to hang some outdoor lights on the opposite side of it.

Can I use the horizontal 3" galvanized pipe that is under the roof as a raceway to run THHN from one side to the other, or do I need to put conduit (EMT, likely) inside (or outside for that matter) the pipe?

It's not a huge deal, as the structure is only about 19' wide.

Here's a photo of a typical corner "joint" of the structure.

 

[dscheidt]

The pipe is not rated as a raceway. Run conduit, or use low voltage stuff with wire in the pipe.

 

[southalabama]

Standard galvanized water pipes have rough interior seams or burrs that can strip wire insulation, and they lack certification under the National Electrical Code (NEC).

Use the proper conduit.

 

[wyliesdiesels]

not listed for use.

install EMT

 

[Codyboy]

That doesn't look like 3", but whatever.
Are you sure its not actually "conduit" instead of pipe?

Either way I would do it but use a bushing on the ends.
However it's going to look dumb and will be unprotected if the wire will be exposed from where it exits the one conduit and going into the other conduit.

 

[Bert_]

You could fish UF through it if you really didn't want to run conduit on the surface.

 

[billconner]

You could fish UF through it if you really didn't want to run conduit on the surface.

Or metal flex.

 

[LXCam]

You could fish UF through it if you really didn't want to run conduit on the surface.

Or metal flex.

As these guys said. It’s not listed as a raceway but it would classify as providing physical protection for a rated sheathed cable assembly or mc cable. Personally I’d run emt.

 

[billconner]

As these guys said. It’s not listed as a raceway but it would classify as providing physical protection for a rated sheathed cable assembly or mc cable. Personally I’d run emt.

Outside I'd prefer ENT (PVC conduit) over EMT.

 

[willf650]

As others have mentioned your only option that would be code compliant would be UF.

MC is not rated for wet locations and your pictures appear that would be the case.

 

[rlitman]

As others have mentioned your only option that would be code compliant would be UF.

MC is not rated for wet locations and your pictures appear that would be the case.

You could pipe with PVC (better outside) or EMT or rigid, flex pipe with LFNC or LFMC (preferred). If you go with UF, you need bushings on the sharp metal ends.

That "pipe" looks like the stuff used for fence posts. If so, and if using UF, I'd get a nice looking aluminum cap and drill it for a plastic romex bushing type clamp.

edit: and then I'm forgetting tray cable - duh. On second thought, that may be the best bet. Mini-split power/control cable is TC rated. Sunlight and water resistant and way more damage resistant than UF.

 

[LXCam]

MC is not rated for wet locations and your pictures appear that would be the case.

They make it in pvc jacketed as well as rated fittings.

 

[willf650]

They make it in pvc jacketed as well as rated fittings.

Yes but it's not readily available to a home consumer, at least around me. It's only sold on large spools at my local supply house. You may be able to buy a "cut" but I've never tried.

I only said MC because someone mentioned "metal flex" and assumed that may be what they were talking about.

I personally would run emt as well but UF fished in the pipes may be the cheapest and quickest solution.

 

[Slowbuilder]

Thanks for all your input. I'll likely run EMT and attach it to the outside of the "pipe". Why is ENT "better" outside? Here in AZ, the severe sunshine attacks PVC with a vengeance. It would have to be wrapped, especially where it's out from under the tin on the roof.

 

[willf650]

PVC is for underground to me and that's about it.

I know my opinion will be met with opposition.

It ages, breaks and expands like a champ.

He maybe talking Smurf tube but I've never seen it installed outside. Thats what I think of when someone says ENT. Never heard anyone call PVC conduit ENT except on this forum I guess.

 

[Stuart in MN]

Nonmetallic won't rust, but it can sag in very hot conditions. The usual solution for that is more closely spacing the conduit clamps or supports. Painting it can help protect it from UV from the sun, but then it becomes a maintenance issue since it will need to be repainted every so often.

 

[wyliesdiesels]

I only said MC because someone mentioned "metal flex" and assumed that may be what they were talking about.

MC and metal flex, aka FMC or greenfield, are not the same thing. MC has conductors, FMC does not.

 

[wyliesdiesels]

Outside I'd prefer ENT (PVC conduit) over EMT.

ENT aka smurf tube and PVC conduit are not the same thing.

 

[wyliesdiesels]

Why is ENT "better" outside?

i wouldnt consider it better outside. it will eventually bake and become brittle. EMT is the way to go

 

[billconner]

ENT aka smurf tube and PVC conduit are not the same thing.

Yes. Is PVC conduit just that? No other designation?

And I did think of it as inside the 3" structural pipe, solving the UV issue. Also did not notice it was in AZ until later, which affects it a lot. EMT outside here would be rusted pretty quickly.

 

[willf650]

Yes. Is PVC conduit just that? No other designation?

And I did think of it as inside the 3" structural pipe, solving the UV issue. Also did not notice it was in AZ until later, which affects it a lot. EMT outside here would be rusted pretty quickly.

RNC -but its antiquated and Rigid PVC is specified in the code book by name at this point.

There are starting to be too many acronyms thrown around in this thread.