We do it nice because we do it twice

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wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
I just built this hair-raising 30 foot 1" emt service riser for an apartment

Used 1" emt and compression couplings

Now inspector, a wonderful person, tells me that the compression couplings have to say rain tight on them.

these were some 10-year-old compression couplings I had in my bag

looks like I'll just go and buy some new ones that say rain tight on them and climb back out on my plank

Did The old compression couplings need to say rain tight on them?

There any good argument I can make before climbing back out on my plank with a safety harness =0

Photos to follow


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wyreman

Senior Member
Location
SF CA USA
Occupation
electrical contractor
That's what I'm talking about!

However, I'm 54 years old, get my on-the-job training about new advances from electrical inspectors :)

She Also showed me a new one how to fit a remodel light into 2 inch thick wooden ceiling

Let mer me see if I find The part I'll post a link


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iwire

Moderator
Staff member
Location
Massachusetts
The older style of compression connectors lost their raintight listing a few years ago.

Some job specs and local codes require compression fittings for all pipe work so you could use the old style for that.

But for wet location use you know must ask for and pay more for raintight compression fittings. The ones we get around here will have black or blue colored parts on them for easy identification by inspectors.
 

iwire

Moderator
Staff member
Location
Massachusetts
Raintight%20EMT%20Black%20Gland.jpg
 

GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The older style of compression connectors lost their raintight listing a few years ago.

Some job specs and local codes require compression fittings for all pipe work so you could use the old style for that.

But for wet location use you know must ask for and pay more for raintight compression fittings. The ones we get around here will have black or blue colored parts on them for easy identification by inspectors.
And, as we learned in another thread, you cannot use one of them with a conduit body instead of a box and expect to get raintight performance for very long, if at all.
 

GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I am not getting that from the thread you linked to but most likely they are not listed :thumbsup: to be used with threaded conduit bodies and boxes due to the straight threads on the connectors.
Exactly, and since neither the mismatched threads nor the gasket, without controlled pressure and good alignment, will provide reliable rain-tightness, they also will not be raintight. The junction of the connector to the EMT will still be raintight, but the connector to box gasket will not work properly.
 

iwire

Moderator
Staff member
Location
Massachusetts
Exactly, and since neither the mismatched threads nor the gasket, without controlled pressure and good alignment, will provide reliable rain-tightness, they also will not be raintight. The junction of the connector to the EMT will still be raintight, but the connector to box gasket will not work properly.

Do you install a lot of these?

Because when I do and tighten them up the gasket does seal agaist the conduit body or box.

They work fine but there are listing issues, just like using LFMC connectors with threaded WP boxes. A common application that works but runs afoul of the listing.
 

GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
Do you install a lot of these?

Because when I do and tighten them up the gasket does seal agaist the conduit body or box.

They work fine but there are listing issues, just like using LFMC connectors with threaded WP boxes. A common application that works but runs afoul of the listing.
I do not install any at all. But in the other thread there were comments that the gasket did not last very long, so you might as well throw it away. I was extrapolating from that.
If you are careful and do not put too much pressure on the gasket because you are using a big wrench to torque the straight thread into the tapered thread, then it may work just fine.

That said, have you checked the seal a year or two later? :)
 

darekelec

Senior Member
Location
nyc
I guess rigid compression connectors do not require those fancy rubber gaskets yet, right?
I am running some rigid aluminum conduit outside nowadays and I was contemplating about it.
 

Ponchik

Senior Member
Location
CA
Occupation
Electronologist
IMO the way WP & conduit bodies are listed to be used with threaded pipe is non sense. I never had any issue with AHJ but then again if they cite me for using a EMT connector, LTFNM connector on WP boxes or conduit bodies then I have no argument.

This listing just doesn't make sense.
 

GoldDigger

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Location
Placerville, CA, USA
Occupation
Retired PV System Designer
I guess rigid compression connectors do not require those fancy rubber gaskets yet, right?
I am running some rigid aluminum conduit outside nowadays and I was contemplating about it.
They probably will end up needing the internal seal at the compression end, but if the threaded end is tapered, it should not need any gasketing.
 

iwire

Moderator
Staff member
Location
Massachusetts
They probably will end up needing the internal seal at the compression end, but if the threaded end is tapered, it should not need any gasketing.

I am not aware of any electrical fittings with tapered threads.

And again I believe using compression RMC connectors with conduit bodies, threaded boxes or hubs would be a listing issue.
 

iwire

Moderator
Staff member
Location
Massachusetts
I do not install any at all. But in the other thread there were comments that the gasket did not last very long, so you might as well throw it away.

Not exactly, I believe someone said they heard that the gaskets don't last long.

I have never seen them fail and if they last for a listed application they would certainly last for the unlisted application.



If you are careful and do not put too much pressure on the gasket because you are using a big wrench to torque the straight thread into the tapered thread, then it may work just fine.

Take it from a guy who has been hands on for 30 something years, this is not rocket science. You tighten it up and it seals. You would have to really go nuts to tighten it so much the gasket squeezes out.


That said, have you checked the seal a year or two later? :)

Specifically? No.

But I am in service and this is not a problem I see.

You know where I see the most water damage? In WP boxes that people do not put drain holes in. The water gets in but can't get out.

When I do my work I always assume water will get in either directly or via condensation and keeping that in mind I always make a place for it to drain. A hole in a box, a hole in a conduit body, a snip out of the gasket on the bottom edge etc.




This is a lot to do about nothing considering IMC and RMC have tapered threads but straight threaded couplings that leak a lot. We have to use type W conductors in wet locations anyway and have to arrange the conduit to drain.

This whole topic is really driven by the ridiculous positions of UL.
 

iwire

Moderator
Staff member
Location
Massachusetts
Sure it is. But look on the bright side; we have color options we never had before. Match the building finish or the mood you are in.

Buy different brands and use them randomly. Drives those OCD guys on the crew nuts. I love doing that.

:D

I do find it funny that folks get all bent out of shape if someone uses a sharpie to mark a pipe but our pipe can come 'inch marked' or have stickers on it and now the fittings can be different colors.
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
:D

I do find it funny that folks get all bent out of shape if someone uses a sharpie to mark a pipe but our pipe can come 'inch marked' or have stickers on it and now the fittings can be different colors.
:D:D. I work with a guy that will throw an absolute fit if you mark a bend with a sharpie. He also looses sleep if all the strut straps and strut are not the same color.
 
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