ECN Forum Forums General Topics of the Trade General Discussion Area Threading 2 1/2" Gal pipe.

IMO
The service mast can be a raceway type or another type such as wood.
That would include other methods such as cable or the other approved methods.

230.28 Service Masts as Supports.
Where a service mast is used for the support of service-drop conductors, it shall be of adequate strength or be supported by braces or guys to withstand safely the strain imposed by the service drop.
Where raceway-type service masts are used, all raceway
fittings shall be identified for use with service masts. Only power service-drop conductors shall be permitted to be attached to a service mast.

As a guy who uses both pipe and conduit I'd say they aren't the same. Maybe its just who manufactures it but the galv coating on pipe doesn't look the same as the coating on conduit. On the other hand I see no difference on the inside, in other words I doubt its a safety hazard to use pipe for a mast?

Walrus, that's kind of the dangerous ground I'm walking on, in suggesting the use - in certain circumstances - of plumbing pipe.

First of all - as a reminder - the AHJ has the authority to approve alternate materials. Article 90 and all that.

Secondly, in the case of pipe .... "listed" seems to be, in this case, a distinction without a difference. (I can hear the howls already!) That is, pipe is a pretty straightforward product, and the ASTM specs for the two products ensure that the similarities are more than skin-deep.

After all, what's there for UL to inspect? Look inside, and say 'yup, it's smooth?'

I've been down this road - the use of plumbing pipe - a few times before. While this was (in the past) on account of the materials needed for chemical resistance, and was run past the AHJ for approval, the principles apply here.

Indeed, I've also had a job where rectangular, structural steel tubing was used as a raceway ... with AHJ approval. It was simply a solution to a wire protection problem. The point, again, is that there IS room for innovation.

Not that any of this is to taken as a wholesale disregard for the usual practices. I've yet to make a mast, myself, from anything but listed RMC. I have no plans to do so, either. If I had a mast that needed to project above a roof more than 7 ft., and my run to the meter below the eave was more than 5 ft., I'd surely consider it, though - along with substantial additional bracing!

Reno, you can cite 90.4 all you want until you're blue in the face.

The fact of the matter is that barring the AHJ's intervention in the process......plumbing pipe is not in accord with the NEC.

I suppose the question to be asked of the AHJ is, "May I have permission to use this unspliced section of plumbing pipe to make this service mast?

Who ever denied involving the AHJ?

My bet is if you installed it in a secure manner, following all the other NEC rules the AHJ would sign the card and drive away without ever suspecting that was plumbing pipe or really caring.

Dang! You mean that "Union-made, UL-Listed" label was on the part I cut off before I threaded it? I took that down to the recycling yard last week.

Whew, Been away from the forumns for a little while, but it did stir up some discussions. Went to the local Blackman Plumbing supply. I was told that they will thread pipe up to 4" in diameter. Good, I thought, I'm good to go. Got to the counter and they said, "We don't thread any one else's pipe. You'll have to buy a length here and we'll thread it for you." Okay I figured, let's price it out. "Hmmm, a length of 2 1/2 gal pipe, and I'll give you a full trade discount, ummmm $182.00." (Seemed a bit excessive to me. Some discount!) Plus I'd have to pay an additional $20.00 to have it cut and threaded. I'll ask the local AHJ if I can use a 2 1/2" compression connector ($50.00). Why didn't I think of that before? D'oh....

The Pipe that Blackman would thread for you, are the threads electrical pipe threads? I think there is a diffrence with the taper. Sounds like the 2 1/2" Comp. connector would be OK.