Outside corner 90 bend emt wet location options

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winnie said:
But would a wet location fitting necessarily be raintight?

Could a standard 'set screw' pulling elbow that is suitably 'non-corroding' be listed as 'wet location'? If it is going to get wet internally anyway, and is supposed to drain, then why put any effort at all into gaskets and sealing?

-Jon
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The intent of raintight fittings is to prevent relatively *rapid* water ingress. Imagine several fittings all leaking in water at the same time. The run may be arranged to drain but the ingress is accumulative and may overload the drainage vehicle (very easily with a small weep hole).

I haven't went looking for any differences between a listed raintight fitting versus a wet location listed fitting. Is there even a distinction? At this point, I think the terms are used interchangeably when applicable. However, raintight seems to be used more for fittings than for wiring methods and condulets.

Only the pulling elbow with dual type entry, i.e. set screw for EMT, threaded for IMC/RMC, and only when used with the latter. Note some say with rigid in marketing materials but I believe the listing qualifies either IMC or RMC.
 
hbiss said:
Not pewter but aluminum. I've used more of those than I care to count and I've never had a problem with the threads. Maybe those from China you would. As for set screw LBs with cover gaskets, you do know that that the gasket is a separate item and the supply house guy might not give you one even for threaded LBs. Or he might give you one with a SS LB.

-Hal
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All the cast aluminum conduit bodies I ever purchased were sold with gasket and cover already installed. Malleable iron bodies you need to also order a cover and gasket as separate items.

winnie said:
But would a wet location fitting necessarily be raintight?

Could a standard 'set screw' pulling elbow that is suitably 'non-corroding' be listed as 'wet location'? If it is going to get wet internally anyway, and is supposed to drain, then why put any effort at all into gaskets and sealing?

-Jon
Click to expand...

Smart $ said:
The intent of raintight fittings is to prevent relatively *rapid* water ingress. Imagine several fittings all leaking in water at the same time. The run may be arranged to drain but the ingress is accumulative and may overload the drainage vehicle (very easily with a small weep hole).

I haven't went looking for any differences between a listed raintight fitting versus a wet location listed fitting. Is there even a distinction? At this point, I think the terms are used interchangeably when applicable. However, raintight seems to be used more for fittings than for wiring methods and condulets.

Only the pulling elbow with dual type entry, i.e. set screw for EMT, threaded for IMC/RMC, and only when used with the latter. Note some say with rigid in marketing materials but I believe the listing qualifies either IMC or RMC.
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My opinion - the manufacturers needed to push their new "raintight fittings" and got a change in how they are listed. Before they made what they call raintight today, we got along just fine for many many moons with standard compression fittings. Standard compression still keeps out more water then what forms inside as condensation. Most raintights I have used are difficult to insert raceway without completely taking them apart adding more time to installation with literally nothing being gained from it. We used to always put standard compression fittings into myers hubs when entering top of an enclosure, the new raintight fittings come with a gasket - makes sense to include gasket as they are not supposed to be listed for use in hubs - the gaskets don't hold up to the weather, end up cracking and even completely falling out of place within just a couple years. I have gone back to using myers hubs. Not to mention once that gasket is gone there is extra space and the fitting is loose and is no longer doing it's "self bonding" thing. The whole raintight fitting thing is a scam to sell more expensive products with no real benefit IMO. Sure for 1/2 and 3/4 inch it don't add that much material cost to a job, but for the company that manufactures millions of them - it adds up.
 
ActionDave said:
Funny thing to think about, you make a conduit run above ground and the hand wringers get all flustered about moisture; run conduit underground, where you have constant moisture rain or shine day or night summer or winter, and nobody says a thing.
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Well said!:thumbsup::thumbsup: and the conductors are "W" rated.

Not to stir things up but I don't think CMP have any manufacturer reps during their meetings. :happyno:
 
kwired said:
+1

and the "raintight fitting" thing is a listing issue and not a direct code issue.
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jumper said:
Manufacturer reps are on many CMPs. NEMA has plenty of pull.
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I was being jocular. I know they have reps on the CMP.

My comment was towards the rain tight fittings. IMO, rain tight fittings are not necessary in our installations.
 
Yeah the UL listing for EMT Conduit Fittings (DWTT), has been incomplete for decades and obviously the manufacturers don't care.
To be code compliant everyone would need to just simply use IMC or PVC for outdoor work.
T&B actually depicts a UL/NEC violation in their catalog showing a image of a bell box with a raintight EMT connector connected to it.
I actually asked UL about this and their reply was that use (without locknuts) has not been investigated I.E basically like "pay us to investigate that".
I imagine if your really attached to using EMT get special permission in writing to waive 358.6 from your AHJ before you start the job. I have done this in the past. Any AHJ (inspector) I have ever dealt with will approve 110.3(A) EMT raintight connectors threaded into an LB without the use of a locknut.
 

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I've never had an ahj call me out on emt into an lb or a bell box. My question is has any seen any real issues using raintight conns into a threaded lb or bell box? Is the concern bonding?

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electrofelon said:
Guys, I'm pretty sure those "combo" threaded/SS lb's are listed for use with emt connectors, no?
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They likely accomplish bonding requirements if you tighten the set screw - next question is are they "rain tight"? My guess is they haven't been tested for that so they won't have any listing for that.
 
electrofelon said:
I would think using a RT emt conn would do it.
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I would as well, doesn't mean they have evaluated it for the application though. As a general rule straight threaded fittings have never been evaluated for use in threaded hubs period, many of us use them that way all the time though.
 
QUOTE=kwired All the cast aluminum conduit bodies I ever purchased were sold with gasket and cover already installed.

So that's where all those gaskets came from that I found on the floor of the truck. :roll:


Malleable iron bodies you need to also order a cover and gasket as separate items.


Yeah, I must have been thinking about malleable bodies and the gaskets being separate items.

-Hal
 
kwired said:
I would as well, doesn't mean they have evaluated it for the application though. As a general rule straight threaded fittings have never been evaluated for use in threaded hubs period, many of us use them that way all the time though.
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I generally agree, but those combo lb's say right on the box "for emt and RGS". When you use them with emt are you supposed to just jam the pipe in there without a box connector?
 
kwired said:
They likely accomplish bonding requirements if you tighten the set screw - next question is are they "rain tight"? My guess is they haven't been tested for that so they won't have any listing for that.
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Not to be pedantic but this issue really bugs me.
From what UL informed me that is correct, the LB is not listed for wet or damp locations when using it with its set screws and EMT directly.
There is no code compliant (2014 NEC 358.6) way in a wet or damp location to connect a rain tight EMT connector (straight threads) to a conduit body like an LB or a bell box threaded hub (tapered threads).
Side note; the requirement for EMT to be listed was proposed by Allied tube & Conduit Co (proposal 8-66) and was adopted in the 1996 NEC. It had opposition for similar reasons
"EXPLANATION O F NEGATIVE: The listing requirement restricts the options open to the
user. In some cases, there is no listed material available."
Also there were no documented problems for the 80+ years prior of unlisted EMT.
I recommend everyone on this forum ask your inspector for special permission to waive 358.6 next time you want to thread a raintight fitting to a lb or bell box and see if any turns you down.
Cheers
 
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