jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
No, you use a sealing locknut on the outside. (Google it.)
Raintight fittings and emt
- Thread starter Solar_ice_caps
- Start date
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
This is one of my pet peeves. A money grab by manufacturers who made a product that isn't necessary. The inside of a conduit outdoors is considered a wet location, so why in the bleeping universe do I need raintight fittings on it?
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
Only required if above live parts. A standard locknut is still legal because threaded rigid fittings don't require rain tight. The panel or disconnect is what dictates needing the sealing when above live parts. I still avoid the water though.
Interesting; at least one outdoor box vendor says their hubs accept any threaded fitting: https://hubbellcdn.com/specsheet/5320-0.pdf
The raintight EMT compression fittings ship with gaskets on the threaded end; I would think that would be enough given that the box vendors approve the fittings. I don't see what the locknut does other than decrease thread engagement between the adapter and the box hub.
- Location
- Illinois
- Occupation
- retired electrician
But the UL Guide Information for "Conduit Fittings" (DWTT) says:
I have not seen that marking in the field.
11Haze29
Member
- Location
- Rhode Island
- Occupation
- Electrical Engineer
Conduit is never 100% watertight, and trying to make it 100% watertight is a futile effort. Mother Nature will always win in the end.
My philosophy has always been to assume water will enter the conduit and to use gravity to my advantage. Always enter and leave and enclosure from the bottom, or lower side below any internals. Then create a low point in the conduit and install a conduit drain. I usually drill a 1/4" hole in the bottom of the enclosure as a means to drain the enclosure should it be infiltrated with rainwater. With smaller conductor, you add a small downward kink in the conductors to create a drip edge. Water will migrate down a cable like water clinging to a bad water pitcher.
My philosophy has always been to assume water will enter the conduit and to use gravity to my advantage. Always enter and leave and enclosure from the bottom, or lower side below any internals. Then create a low point in the conduit and install a conduit drain. I usually drill a 1/4" hole in the bottom of the enclosure as a means to drain the enclosure should it be infiltrated with rainwater. With smaller conductor, you add a small downward kink in the conductors to create a drip edge. Water will migrate down a cable like water clinging to a bad water pitcher.
kwired
Electron manager
- Location
- NE Nebraska
Them gaskets are junk. When they first started pushing these RT fittings I used them as intended. Came back to a few installs within just a year or two and find the gasket deteriorated enough that it doesn't seal and leaves more of a hole for leakage than had I not used the gasket at all. Have since gone back to using a myers hub and not using the gasket or locknut that comes with the fitting.
You don't use the locknut on a box with integral hub that would decrease thread engagement as you mentioned, it is for the inside of drilled or KO holes in thin walled enclosures.
Here is a almost 20 year old thread with some history on this topic:
UL listed emt fitting for a wet location (watertight)
Hello, Has anyone seen an approved EMT fitting for wet location. I know that UL pulled the approval in 2001 or there about. Has anyone seen an approved fitting yet? How are you all dealing with outdoor piping?
forums.mikeholt.com
Yes of course, that's why its use as in post #5 seems unnecessary to me.
kwired
Electron manager
- Location
- NE Nebraska
Where are you proposing to place it if you did use it other than on the outside of the enclosure?
I have brought up the fact that the gaskets on most these fittings are junk and deteriorate in the elements in relatively short time. This leaves them with more gap for leakage than had you not used the gasket at all, and reason I quit using them. So far no inspector has ever challenged me with this. But from experience if one ever does I will not go down easily.
Solar_ice_caps
Member
- Location
- Florida
- Occupation
- Solar EPC
Now I’m wondering on my original design because I went back to Lowe’s and saw that these EMT LBs are marked on the box for Wet Locations even though they are set screw:
Slowly learning the nuance between Dry/Wet Location rated vs rain/water tight.
My understanding now, especially since inside the conduit is considered wet, is that the fittings simply need to be rated for wet locations not any kind of “tight.”
To that end I’m looking at just replacing the screw adapters with raintight adapters and being done with it .
Thoughts?
Slowly learning the nuance between Dry/Wet Location rated vs rain/water tight.
My understanding now, especially since inside the conduit is considered wet, is that the fittings simply need to be rated for wet locations not any kind of “tight.”
To that end I’m looking at just replacing the screw adapters with raintight adapters and being done with it .
Thoughts?
jaggedben
Senior Member
- Location
- Northern California
- Occupation
- Solar and Energy Storage Installer
I feel like that label is BS.
Solar_ice_caps
Member
- Location
- Florida
- Occupation
- Solar EPC
Yeah, that's a concern I had. The web listing description says dry locations....
Is there a way to look up if something is listed for wet location use? I can look up the UL number but I'm not sure where to go from there.
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
If it's threaded on the inside also then that may be used like we mentioned about threaded imc and rmc don't need rain tight just threadless fittings.
Solar_ice_caps
Member
- Location
- Florida
- Occupation
- Solar EPC
Do you mean threaded?
letgomywago
Senior Member
- Location
- Washington state and Oregon coast
- Occupation
- residential electrician
Yes sorry
I'm agreeing with you, in that you don't use it at all with a hub.
Interesting I highly doubt its a listed rain tight EMT fitting on its own.
I bet you'd have to use a piece of rigid or IMC to keep the UL listing.
Contact the manufacturer and post the UL listing file DWTT7.E121488 here.
Sigma Engineered Solutions | Combination Conduit Body – Type LB
Used with threaded rigid conduit, IMC or EMT for providing access to the interior of a conduit system for pulling,...
sigmaengineeredsolutions.com
E121488 for Sigma Engineered Solutions | UL Solutions
productiq.ulprospector.com
Solar_ice_caps
Member
- Location
- Florida
- Occupation
- Solar EPC
Interesting I highly doubt its a listed rain tight EMT fitting on its own.
I bet you'd have to use a piece of rigid or IMC to keep the UL listing.
Contact the manufacturer and post the UL listing file DWTT7.E121488 here.
Sigma Engineered Solutions | Combination Conduit Body – Type LB
Used with threaded rigid conduit, IMC or EMT for providing access to the interior of a conduit system for pulling,...E121488 for Sigma Engineered Solutions | UL Solutions
Wanted to close the loop on this so I reached out to Sigma directly about these and this was their response:
"The parts ARE listed for use in Wet Locations. As for the 3 different variants, the difference is as below."
LBSS050 – This is just the Conduit Body without any Gasket & Cover
LBSS050AN – This is Conduit Body assembled with a Stamped Cover and Neoprene Gasket
LBSS050CG – This is Conduit Body assembled with a Die Cast Cover and Fiber Gasket"
These PNs are specifically their EMT LBs with the double set-screw: https://sigmaengineeredsolutions.com/?s=LBSS050
I think that brings me back to what I've come to understand in this thread about the nuances between 'wet location rated' and rain and/or watertight.
The conduit body can be used in a wet location and is likely designed not to corrode, etc. That doesn't necessarily mean it's meant to keep water out. In this case though, the EMT butt-joint inside the screw connector may provide some sufficient level of protection that lets it be listed for wet locations.
kwired
Electron manager
- Location
- NE Nebraska
You didn't ask about "ingress protection" ratings
With EMT and the set screws vs a threaded entry.