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Posted By: Admin Die Cast Connector on Service Mast Riser - 09/11/04 10:50 PM
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Contractor used a EMT/IMC/RIGID connector on a service mast riser an I rejected it. He reported a complaint on me and said I was picking on him. I see a violation of the listing being used in a wet location. I also do not beleive this set up has adequate strength as requires in article 230. The service drop is 109' coming from across the road. He has called all the brass to go look at it with him. IMO this is NOT a code compliant installation.

- necbuff
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Posted By: iwire Re: Die Cast Connector on Service Mast Riser - 09/11/04 10:54 PM
déjà vu
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/12/04 02:02 AM
Wouldn't fly around here! Connector, or that strap? Looks like a drop holder without the insulator, used as a strap? Is the lower conduit EMT?

So this guy doen't own a threader, or too cheap to buy a listed theadless connector suitable for the purpose.
Posted By: Dave55 Re: Die Cast Connector on Service Mast Riser - 09/12/04 02:50 AM
I think you nailed this one necbuff. I'm not an inspector, but it looks like he found an EMT fitting that would fit IMC, like maybe a 3"EMT connector would fit 2 1/2" IMC. He did it out of cheapness or ignorance, but it's wrong. He's looking at his cost to pull it apart & put it back together & look like a fool in the process. If he pursists, large EMT connectors sometimes are stamped with the size, which will show the error(the hub on the meter socket may be stamped with the IMC size). This could be a big leaker by capilary action.

Dave
Posted By: Scott35 Re: Die Cast Connector on Service Mast Riser - 09/12/04 09:20 AM
This one seems like an easy one... but let's try it from "Another Angle" [Linked Image]

  • Do any Set Screw Fittings exist, which are UL Listed as Weatherproof - namely EMT Set Screw Fittings?,
  • Was there not a "little" issue a few Months back, with all Manufacturers of Compression Fittings for EMT losing UL Listings as to the Weatherproof abilities... and only one brand finally received Listing - and this was for Fittings DESIGNED for just that purpose?


Just seems very counter-productive (and stupid) to install a Set Screw EMT Fitting outdoors and in the path O' the Weather.

Unless the Fitting is Listed for that purpose (if so, please let me know!!!), the Installation is "Caa-Caa Del Toro"
(Bull Poo-Poo)
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Scott35
Posted By: iwire Re: Die Cast Connector on Service Mast Riser - 09/12/04 10:01 AM
Yes you can get Die Cast Set Screw RMC/IMC connectors.

Here is one company that makes them.


Why you would want to use one is another story.

In the larger sizes some set screw connectors are listed for RMC, IMC and EMT

I have not seen or heard of any that are weather proof.

That aside the service in the picture has a couple of violations that jump right out at ya.

230.28 and 344.42

This was brought up at another forum but I thought it was interesting.

Are threaded conduit couplings listed as raintight?

Bob
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/12/04 03:57 PM
That's right, compression connectors are only listed for rain-tight as you throw them over the border into Canada. [Linked Image](except that one company no-one around here carries)

So necbuff, what is being used to support that riser? The hole that he cut in the roof? Those straps, I have not seen before, are those common anywhere else?
Posted By: walrus Re: Die Cast Connector on Service Mast Riser - 09/12/04 04:34 PM
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Are threaded conduit couplings listed as raintight?

Not sure one way or the other but running threads won't keep water so I don't see how they could be. They sure the heck are alot stronger than a set screw connector.
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/12/04 04:51 PM
Treaded couplings should be, after all with a small amount of pipe compound you could have it be gas tight! And, for older buildings Rigid Galvanized was common water pipe for a long time.

I usually add a little Noalox to the threads anyway, for ease of installation, wrench tight a little further that way. But we are looking for "Rain-Tight", not "Water-Proof".

Reguardless, a set screw is neither.
Posted By: iwire Re: Die Cast Connector on Service Mast Riser - 09/12/04 05:03 PM
The problem is that RMC threaded couplings as Walrus pointed out have running threads (not tapered) While the galvanized ones for plumbing have tapered threads.

I do use RMC threaded conduits outside but I do not believe they are listed as raintight. [Linked Image]
Posted By: Dave55 Re: Die Cast Connector on Service Mast Riser - 09/12/04 05:12 PM
Though it's not in the NEC, I apply 100% silicone caulk liberally on the threads and joints on exterior services. It's flexible and made to repel water. I also make sure there are small drain holes in the meter socket (usually provided in manufacture).

Dave
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/12/04 06:02 PM
Had to go out to the truck to check, yep factory (Un-tapered)running thread, So why is it that feild threads are tapered? Hmmm...
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344.28 Reaming and Threading.
All cut ends shall be reamed or otherwise finished to remove rough edges. Where conduit is threaded in the field, a standard cutting die with a 1 in 16 taper (3/4-in. taper per foot) shall be used.
And, I beleive this to mean running threads past the normal range to allow connection without an Ericson type 3-piece coupling?
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344.42(B) Running Threads. Running threads shall not be used on conduit for connection at couplings.

Dave55, not sure if silicone chalk is not a reduction in conductivity. Noalox, and Penetrox are at least listed for Aluminum conduit, and the zink in them isn't reactive on steel. Often HD Corrosion-X or thread cutting oil used to cut the threads is enough to keep most water out.

[This message has been edited by e57 (edited 09-12-2004).]
Posted By: DougW Re: Die Cast Connector on Service Mast Riser - 09/12/04 06:23 PM
I think if there were double anchors above that transition, he'd have an argument for strength of the mast. I can kinda understand the connector - his mindset is probably that the non "tight" end is downward facing, and thus not subject to rundown H2O.

If I were him, I would have used the full length piece of IMC from the box to the coupling, and then joined the short length to the full sized one with a threaded coupling. I would have put the cut end up, and clamped the weather head to the cut end. Uniform joining of pipe, Code compliant, and no blatant "WTF?" coupling in the middle of the run.
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/12/04 06:33 PM
Doug, I would have done it that way too.
Posted By: necbuff Re: Die Cast Connector on Service Mast Riser - 09/12/04 07:58 PM
I would have took this installation if he had put the joint below the first strap, used a rigid coupling between the straps or guy'd the riser off. maybe not 100% code compliant but I would feel a resonable level of safety had been accomplished. I am most concerned with the strength of the riser. This is a 109' pull here. As for the straps, we call them stand off's or thru wall bolt clamps. They have a bolt that goes thru the wall and are required by the poco. This guy calls when things do not go his way, you guys know the type. This is 2 1/2" RMC or IMC.

[This message has been edited by necbuff (edited 09-12-2004).]
I'm not sure what size the service is or the mast here. Around here your saposed to use 2 1/2" steel ridgid for 100a and 3" for 200 amp if it is used as a suport for the service drop. I would say it should have one more strap also. Utility requires max 4' 2" from head to first clamp using min 1/2" bolts.

Besides NEC does it meet the local utility requirments?

They could have done this with out a threader. 1 stick meter to threaded coupling. 2nd stick cut off at weather head.

I would be angery if I seen this kind of work approved.

Tom
Posted By: iwire Re: Die Cast Connector on Service Mast Riser - 09/12/04 08:22 PM
It is very tough to guess or know what each areas POCO wants. Some POCOs require the top stick of pipe to be a full stick, the cut one goes at the bottom.

Personally that is also how I do it, on the few masts I have done I have not relied on a coupling to hold the drop. I have seen a few broken conduits and the break is always at the closest thread to the coupling. Of course that is just a personal preference not an NEC requirement. [Linked Image]

Bob
Posted By: Dave55 Re: Die Cast Connector on Service Mast Riser - 09/15/04 10:54 PM
Right Mark.

I assemble everything wrench-tight, then apply the silicone.

Dave
Posted By: e57 Re: Die Cast Connector on Service Mast Riser - 09/16/04 07:47 AM
Ohhh....[thumbsup] Cool, Dave, I thought you were lubing the threads with it there.
Posted By: necbuff Re: Die Cast Connector on Service Mast Riser - 09/16/04 11:27 PM
Got overrode... Life goes on.
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