Outside corner 90 bend emt wet location options

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Mustwin351

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Surprisingly I’ve never come across this situation but how do you guys like to to run emt around an outside corner 90 degree bend in a wet location? An offset with a 90 would look terrible to get around the corner and I have not seen any rain tight fittings for the job. I guess an an LB condulet with silicon for the emt compression connectors?
 
Mustwin351 said:
Surprisingly I’ve never come across this situation but how do you guys like to to run emt around an outside corner 90 degree bend in a wet location? An offset with a 90 would look terrible to get around the corner and I have not seen any rain tight fittings for the job. I guess an an LB condulet with silicon for the emt compression connectors?
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I just use rain tight connectors in a conduit body. Technically they are not listed to use their straight threads in the conduit body though, so if you want to comply with that you just may need to use RMC/IMC.:blink:
 
Mustwin351 said:
Surprisingly I’ve never come across this situation but how do you guys like to to run emt around an outside corner 90 degree bend in a wet location? An offset with a 90 would look terrible to get around the corner and I have not seen any rain tight fittings for the job. I guess an an LB condulet with silicon for the emt compression connectors?
Click to expand...

You cannot use silicone as a replacement for the proper fittings.
 
infinity said:
You cannot use silicone as a replacement for the proper fittings.
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Isn’t (not always) generally acceptable with AHJ’s to allow conduit bodies or bell boxes with raintight emt fittings with silicone on the threads if you are using an equipment grounding conductor?
 
Smart $ said:
To be completely compliant with Code and listings...
1 EMT/IMC/RMC pull ell (or LB)
2 RMC close nipples
2 raintight EMT to RMC combination couplings

View attachment 18806 (http://www.tnb.ca/en/pdf-catalogues...dustrial-fittings/B-Industrial-Fittings-E.pdf, page B56)
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Never knew those existed!
If you don't get a hold of those, the RMC close nipples can go into RMC couplings and EMT compression connectors. The RMC nipples if they show can get rusty so some galvanized paint can help.
 
Ozymandias said:
Yes, and I thought EMT compression connectors where rain tight except when buried where you have to add means of protection
(Cow's LB picture was supposed to go here)
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An EMT compression fitting with just a metal ferrule is typically listed only as concrete tight... not raintight.
 
Ozymandias said:
Never knew those existed!
If you don't get a hold of those, the RMC close nipples can go into RMC couplings and EMT compression connectors. The RMC nipples if they show can get rusty so some galvanized paint can help.
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TTBOMK [metal] connectors are not listed for use with any threaded entry or fitting. They are only investigated for grounding continuity using locknuts.
 
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It seems ridiculous that this conduit body is only suppose to be used with INC or rmc. It is made from pewter and seems like it would fall apart as soon I tightened it up the conduit threads.

I also have another conduit body with a gasket under the cover but it has set screws for emt conduit (and it is not threaded inside the conduit body for RMC)....obviously it would not be for use in wet locations but yet it is provided with a gasket. (Sorry for the rant)
 
Mustwin351 said:
Isn’t (not always) generally acceptable with AHJ’s to allow conduit bodies or bell boxes with raintight emt fittings with silicone on the threads if you are using an equipment grounding conductor?
Click to expand...
Don't know of any AHJ in its entirety, but I certainly do not have intimate knowledge of all AHJ's. :D

There may be some inspectors which permit it... so IMO it's a shirt-pocket ruling.
 
Mustwin351 said:
View attachment 18807
It seems ridiculous that this conduit body is only suppose to be used with INC or rmc. It is made from pewter and seems like it would fall apart as soon I tightened it up the conduit threads. ...
Click to expand...
I have seen many of the hubs on those breaks apart when the conduit is overtightened.

I've even seen a few instances where the hub doesn't break apart until after the run is completely installed, wires pulled. :cry:
 
Mustwin351 said:
View attachment 18807
It seems ridiculous that this conduit body is only suppose to be used with INC or rmc. It is made from pewter and seems like it would fall apart as soon I tightened it up the conduit threads.

I also have another conduit body with a gasket under the cover but it has set screws for emt conduit (and it is not threaded inside the conduit body for RMC)....obviously it would not be for use in wet locations but yet it is provided with a gasket. (Sorry for the rant)
Click to expand...

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
 
I am curious. Since EMT outside is considered a wet location, do you actually need a raintight fitting for a corner? My understanding is that the fittings need to be listed for wet locations, and that they must _either_ prevent moisture from entering or accumulating, eg. with drain holes.

Do there exist pull elbows or conduit bodies for EMT that meet the requirements by draining rather than being water tight? Eg. listed to be exposed to moisture and be in a wet location without actually trying to keep the water out?

Also, in the original question mentioned going around the corner using an offset followed by a 90, which would push the conduit away from the corner in order to provide space for the radius of the bend. Another option for bending to get around the corner is to use a pair of vertical 90's. One 90 to go from the wall to parallel to the corner, and the second 90 to go from parallel to the corner edge to the other wall. I leave it to the reader to decide if this would look good or not....

-Jon
 
Even a RMC nipple to RMC coupling to rain tight emt connector would not be correct as the threads are not the “correct” match.

So technically emt cannot be run to a bell box in a wet location because there is not a listed connector for a bell box to emt connection?

is there a way without running RMC or IMC in a metal raceway.
 
winnie said:
I am curious. Since EMT outside is considered a wet location, do you actually need a raintight fitting for a corner? My understanding is that the fittings need to be listed for wet locations, and that they must _either_ prevent moisture from entering or accumulating, eg. with drain holes.

Do there exist pull elbows or conduit bodies for EMT that meet the requirements by draining rather than being water tight? Eg. listed to be exposed to moisture and be in a wet location without actually trying to keep the water out?

Also, in the original question mentioned going around the corner using an offset followed by a 90, which would push the conduit away from the corner in order to provide space for the radius of the bend. Another option for bending to get around the corner is to use a pair of vertical 90's. One 90 to go from the wall to parallel to the corner, and the second 90 to go from parallel to the corner edge to the other wall. I leave it to the reader to decide if this would look good or not....

-Jon
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Wet location (i.e. raintight) fittings are not meant to keep out moisture. Humidity will penetrate almost any system unless it is constantly purged with 'dry' air. Condensation follows with changes in outside temperature (more so in the north). This is why raceways are required to be arranged to drain. While many resort to weep holes at various locations, there are actually drain fittings for the purpose... but they are relatively much more expensive. :happyyes:

While I've considered using a dogleg 90-90 offset many times through the years, I've never actually used one. Aesthetically, I think it would look terrible... but may be ideal for some installation which aesthetics make no difference. :blink:
 
Smart $ said:
Wet location (i.e. raintight) fittings are not meant to keep out moisture. Humidity will penetrate almost any system unless it is constantly purged with 'dry' air. Condensation follows with changes in outside temperature (more so in the north). This is why raceways are required to be arranged to drain. While many resort to weep holes at various locations, there are actually drain fittings for the purpose... but they are relatively much more expensive.
Click to expand...

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
 
Mustwin351 said:
...I also have another conduit body with a gasket under the cover but it has set screws for emt conduit (and it is not threaded inside the conduit body for RMC)....obviously it would not be for use in wet locations but yet it is provided with a gasket. (Sorry for the rant)
Click to expand...

Mustwin351 said:
Even a RMC nipple to RMC coupling to rain tight emt connector would not be correct as the threads are not the “correct” match.

So technically emt cannot be run to a bell box in a wet location because there is not a listed connector for a bell box to emt connection?

is there a way without running RMC or IMC in a metal raceway.
Click to expand...
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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