Emergency TIA needed ASAP for raintight EMT fittings

don_resqcapt19 said:
In my opinion, 225.22 pretty much prohibits top entry. Maybe if you come down to a tee, with a drain in the bottom opening and then LB from the side opening into the top, it would be arranged to drain, but other than that, I don't see how you comply with 225.22. This rule was added in the 2002 code.
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Thanks, I'm going to use that when I see this in the future. I guess it would be OK for a 3R jbox, but as we know, arranging to drain into an ATS mechanism is a bad idea.
 
tortuga said:
Its just amusing to me that every electrician I have ever met including myself use rain tight EMT threaded adapters to thread into a 'hub' like WP 'bell box' or an LB, which voids the listing. So when connecting to a HUB the listing is voided regardless if you throw that o ring gasket away or not.
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My take is that almost nobody actually thinks this is true. Also threaded hubs don't leak and aren't what this thread was about.
 
I find it interesting that no one pointed out that the inside of a conduit run outside is considered a wet location, so raintight connectors are nothing but another money grab by manufacturers.
 
jaggedben said:
My take is that almost nobody actually thinks this is true. Also threaded hubs don't leak and aren't what this thread was about.
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The way I understand it and this may be out of date, is 358.6 Requires EMT fittings to be listed, UL Certifies (Lists) Conduit Fittings under the product category for Conduit Fittings (DWTT),
The UL white book states on P 141:
"All male threaded fittings and nipples have only been investigated for
use with locknuts.
Fittings with internal female threads (e.g., hubs, conduit bodies, cou-
plings) have only been investigated for use with threaded rigid conduit."
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So the options for connecting to a threaded hub are:

1) Threaded RMC/IMC

2) An NPT threaded fitting that is labeled for hubs. Pretty sure these will not come with a locknut, although I don't recall if UL 514B prohibits supplying them with a locknut. [Conversely, any threaded fitting with non-standard threads that is only for use as a box connector to a sheet metal box is required to be supplied with a locknut.] Example:

Mighty-Merge® Raintight EMT to NPT Hub Connector 1", SS Nipple

Die cast zinc raintight EMT to NPT hub connectors are used to join EMT to NPT-threaded hubs, conduit bodies and bosses. A patented design provides a listed raintight seal in wet locations, protecting inner wiring systems from water.
nsiindustries.com nsiindustries.com

3) A PVC male adapter. These are covered by UL 651, not 514B, and it specifies that the male adapters are for use with any female threaded hub or fitting. [A PVC box connector is a different type of fitting, that has an internal flange and is designed to glue into an external coupling.]

Any other options?

Cheers, Wayne
 
wwhitney said:
So the options for connecting to a threaded hub are:
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I think the big problem is 358.6, not every 'listing' can cover every safe a workman like installation, I think 358.6 should be notched down from listed to to 'approved', allowing the AHJ to approve an installation that may not be a 'listed' combination.
There is very old thread on here where Joe Tedesco was stating a similar thing, that you can't go from a FMC male adapter to a Rigid coupling to a EMT connector as it voids the 'listing'.
If I already have a listing violation connecting a RT EMT fitting to a hub, then just go back to using 'concrete tight' male adapters when entering a 'hub', neither fitting is listed for the purpose, and the interior of the raceway is a wet location no matter what we do.
 
tortuga said:
I think the big problem is 358.6
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I don't see that as a problem, EMT fittings should be used in accordance with the way they are tested in the listing standard.

To connect EMT to a hub, you can use a short rigid nipple along with a listed EMT to Rigid transition fitting, which has female threads. Or in sizes 1/2" to 1", the product mentioned in my previous post will do it as a single piece.

Seems like people are just doing it wrong either out of ignorance or convenience (don't want to stock the extra parts).

Cheers, Wayne
 
tortuga said:
...
The UL white book states on P 141:
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I mean...
So. What.

First of all, if 99.9% of people in the trade don't actually read the UL white book or care, my original statement simply stands. But to elaborate...

The UL White Book doesn't have the force of code. The code just says (110.3(B)) that listed equipment "shall be used in accordance with any instructions included in the listing or labeling." So unless the listed items have instructions that explicitly prohibit screwing using an NPS connector in an NPT threaded hub (or vice versa), there is no clear code violation. I have never seen instructions that are explicit about this stuff; in fact I don't think I've ever seen instructions come in the box for raintight EMT fittings or conduit bodies! ;) 358.6 just says connectors stuff shall be listed; it doesn't add any relevant detail here. Your connector comes with a UL mark, okay, you've complied. I can see how the White Book could be appealed to in a borderline case where one is asking if a fitting is 'suitable' for the purpose (110.3(A)). But if I've never IRL met any person in the trade, install or AHJ, who thinks that an EMT connector in a rigid conduit body isn't suitable for general purposes, after having seen it thousands of times ... I'd say that's not a borderline case. I'd say it's generally accepted as suitable.

Given what the code says (and doesn't say) it's also weak to rest this argument on what UL standards require to be 'investigated.' Again, that doesn't clarify what is prohibited or approved by listing to the standard. The code doesn't explicitly require that products 'investigate' every possible use; that isn't the language the code uses. Perhaps being investigated for the things mentioned in the White Book is sufficient for most general uses.

Finally, where stuff like this apparently actually matters, such as when article 505 applies, the code actually is specific about the use of NPT threads and such. The silence about NPT vs. NPS threads in 314 and 358 (is it all of Chapter 3?) implies that where such special requirements do not apply, this stuff doesn't matter, and isn't a violation.
 
Why is it that Arlington can make threads that can fit anything? Look at the images here:

Arlington | GB5T Product Information

Four termination points, more than required by 250.94(A)(2) of the NEC, handle multiple hookups of communications systems ‐ telephone, CATV or satellite dish.
www.aifittings.com www.aifittings.com
 
ptonsparky said:
I've seen more than one SS connector used on the bottom side of a 3R enclosure. They never let any water in.
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I remember a regular farmer client of mine wanting me to check something out at a grain storage bin site that he was leasing from someone else several years ago. I remember a rack of all or nearly all NEMA 1 enclosures, motor starter enclosures, fused disconnects, wire way to tie them together. I believe even some set screw fittings were involved here and there. Exterior surfaces of many items had a rusty finish. Surprisingly I noticed the inside of the starter enclosures were pretty clean inside. I don't think there was much for top entries which maybe helped.
 
jaggedben said:
I mean...
So. What.

First of all, if 99.9% of people in the trade don't actually read the UL white book or care, my original statement simply stands. But to elaborate...
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I agree 100%, my soloution to fellons problem in post1 would be to change the requirement for the fittings from 'listed' to 'approved', then your free to use them however an AHJ 'approves'
jaggedben said:
The UL White Book doesn't have the force of code.
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My understanding is it does, I believe Mike taught that at his seminars.
I remember a city inspectors office that had several colors of UL books, white, green etc ..I cant remember what they all were.
UL used to send them out to AHJ for free, now that UL is all online and has a paywall fewer AHJ's use them.

Keep in mind EMT was not required to be a listed product until 1996 and EMT fitting were not required to be listed until 2002.
When the CMP did that they did not require UL to list every way fittings they were commonly used.
If you zoom out and look at the bigger picture of the NEC code changes over the last 20 years many are adding the requirement for things to be 'Listed', like requiring a ziptie to be UL listed. In my opinion electricians should push back against that, as it causes situations like this.
 
tortuga said:
Keep in mind EMT was not required to be a listed product until 1996 and EMT fitting were not required to be listed until 2002.
When the CMP did that they did not require UL to list every way fittings they were commonly used.
If you zoom out and look at the bigger picture of the NEC code changes over the last 20 years many are adding the requirement for things to be 'Listed', like requiring a ziptie to be UL listed. In my opinion electricians should push back against that, as it causes situations like this.
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I think I mentioned this earlier, but I like the IDEA of things being listed, to prevent junk on the market and us having to install it, but that doesn't really seem to be the result. The RT fittings, particularly the ones with the rubber gasket.......I guess there is no test that the locknut be tightened enough to dig thru the paint. Obviously no one at UL has ever installed one. Seems like that should be a test. Along similar lines frequently have fittings where the locknut "skips out" and can't be thoroughly tightened. Recently I also complained about the sharp edges on PVC LB's. Just seems like these people are a bit clueless on some of this stuff and not really sure what we are accomplishing with listing.
 
electrofelon said:
I think I mentioned this earlier, but I like the IDEA of things being listed, to prevent junk on the market and us having to install it, but that doesn't really seem to be the result.
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The thing is manufacturers will keep listing their fittings, I am working on a old industrial building from the 1940's and the EMT fittings are listed, but EMT fittings were not required to be listed in the NEC till 2002.
When the code requires a something to be listed then the way you can use the fitting has a very narrow scope, thats why the code does not require many things to be listed as your aware like transfromers, motors, HVAC equipment, industrial control panels. So if you void the listing of a EMT fitting by using it in a way that its not listed for, an AHJ has to turn you down even if they think what you did is fine. The AHJ's hands are tied by the listing requirement.
Also in the big push to make everything listed they remove 'construction specifications' from the code, these are important things manufacturers need to follow, like no sharp edges in a PVC LB.
I am just proposing to take it down a notch and change it so EMT fittings just need to be 'approved', and reject any PI to require more stuff be listed, then its up to the AHJ. If the AHJ wants everything listed fine thats a local issue.
 
tortuga said:
...
When the code requires a something to be listed then the way you can use the fitting has a very narrow scope, ...
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No.
The code requiring fittings used with (for example) EMT to be listed does not preclude using those fittings for other uses where the code does not require fittings to be listed. The only code violation stems from using the fitting in a manner that violates its *instructions*.

I am just proposing to take it down a notch and change it so EMT fittings just need to be 'approved', and reject any PI to require more stuff be listed, then its up to the AHJ. If the AHJ wants everything listed fine thats a local issue.
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I agree in principle. But I think you're exaggerating the extent to which the code doesn't already allow an AHJ to approve the use of a listed fitting that doesn't come with instructions limiting its use.

Have you ever seen an EMT fitting that came with instructions?
 
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