EMT to Liquidtite

[LJSMITH1]

Given the quality, or more correctly the lack thereof, or many listed fittings I have no idea why we need to use listed ones.

I agree. The offshoring of many manufacturer's fittings has certainly proven this with some major manufacturers (but not all). The contributing problem to the quality, is the major price pressure exerted by the sales side. Everyone wants product practically for free. However, what suffers is the quality and consistency.

However, I do have to say that UL does conduct unnannounced verification testing, and I have seen manufacturers lose their product listings due to failures.

 

[jwelectric]

I don't have a copy of the white book in front of me, but are there any limitations of other types of fittings outlined in the book?

Well here is page100

And here is page 101

For example, is there anything that would prevent me from using a setscrew coupling in a meyers hub?

Nothing except the location of the enclosure

What about a compression fitting with a rigid conduit body?

Nothing I know of

The combinations are endless and I am sure that the standards don't address every one. I am sure that the UL White Book doesn't say that you CAN use the RMC in that specific application. It plain doesn't define anything except the standard methods.

and that is the sweet thing about the NEC, it is a permissive document meaning that unless forbidden then it is allowed.

As for UL Standards, they are consensus based documents which are developed by:

? Manufacturers, which use the standards to design products and systems that meet requirements for certification;
? Regulatory authorities, which reference the standards for products and systems used in their jurisdictions;
? Code development organizations, such as the National Fire Protection Association and International Code Council, and government agencies, such as the Occupational Safety and Health Administration, which adopt and reference UL safety standards; and
? Certification organizations, which apply UL requirements for product evaluations.

While these UL standards may have little to do with the actual installation of the product, they sure do take into account how it is installed when the standards are developed.

Yes I agree that the method outlined above are how the standards are based but the standards still have nothing with mandating the installation.

You obviously have not had an inspection resulting in an issue with the installation that you are discussing. However, in other jurisdictions, I am sure that it is treated differently, no matter how you interpret the codes.

You are right I have never ran into any trouble with this type of installation and no other person should either. It is not a matter how I am interpreting the codes but what is written in the codes.

I ask you, if the application (or combination of fittings) thereof is not mentioned in any UL listing, does it still mean it's ok? It's certainly not my place to say, as the AHJ has the final say per Art 100.

It is never the code official that has the final say. There is always someone that they call boss.

It's obvious that we have separate opinions, and I respect you for that. So...let's agree to disagree...ok?

It is okay to disagree but remember that I have posted the material to back my ?opinion? and am still waiting for your?s

 

[quogueelectric]

You guys are taking this way too seriously. It is just a fromto. simple as that a transitional device that changes something from something to something. What if you used a c condulet or a jbox. Come on someone has to install this stuff while you super geniouses figure out how we are allowed to. Could you make it any more difficult on us?? I dont think so. This is real bs in my opinion and I am no stranger to the bull.

 

[JohnJ0906]

I don't have a copy of the white book in front of me,

White Book

 

[jdsmith]

You guys are taking this way too seriously....

Yep. I will reiterate the point that Mike made a few posts ago that the NEC is a permissive document that allows us to do anything unless it specifically says otherwise. The NEC is the only document that we have to go by - the UL listing only comes in when things are listed and provided with specific instructions. Since my conduit fittings don't come with instructions I'm not violateing what doesn't exist, so I can screw any pipe threads together that I want to.

Happy 4th of July recovery day!!!

 

[iwire]

Yep. I will reiterate the point that Mike made a few posts ago that the NEC is a permissive document that allows us to do anything unless it specifically says otherwise. The NEC is the only document that we have to go by - the UL listing only comes in when things are listed and provided with specific instructions. Since my conduit fittings don't come with instructions I'm not violateing what doesn't exist, so I can screw any pipe threads together that I want to.

Very well put and that also describes my postion as well.

 

[LJSMITH1]

White Book

Thank you!

 

[iwire]

Check this out from OZ_Gedney regarding chase nipples and rigid conduit couplings.

Bushed Conduit Nipples

Use:

Use through knockout to connect box to conduit coupling.

Use with a locknut to connect two boxes side by side or back to back. Use with a locknut to connect fixture housings in continuous runs.

This can be found on page 4 of this pdf

Now the threads on a chase nipple are no different then the threads on a LFMC or EMT connector.

Considering I have NEVER seen any specific installation directions or labeling on a RMC coupling then using it with connectors is not a violation of 110.3(B)

 

[LJSMITH1]

Yep. I will reiterate the point that Mike made a few posts ago that the NEC is a permissive document that allows us to do anything unless it specifically says otherwise. The NEC is the only document that we have to go by - the UL listing only comes in when things are listed and provided with specific instructions. Since my conduit fittings don't come with instructions I'm not violateing what doesn't exist, so I can screw any pipe threads together that I want to.

Happy 4th of July recovery day!!!

I agree with that statement. I guess the issue I have a problem with is when a field application of a product is not specifically defined in documents like the UL white book, NEC, or other related publication. I am sure we can all come up with numerous instances where combinations of fittings have been used to transistion from one raceway to another. I like to call them 'frankenstein fittings'.

I am under the impression that in order to have the performance of the product as guaranteed by the UL listing process, it must be used exactly as tested in the UL specification. Any variation from that use, will basically put the fitting in an area of uncertainty because no testing in a controlled environment has been done. Am I misguided?

Here's one story that I have which relates to this discussion:

I had a call from an electrician who stated he was having problems installing a 2.5" EMT/RIGID setscrew connector into a 2.5" Meyers Hub. It would only thread in 1-2 turns and then jam (wrench tight). He was flagged by the AHJ, because the connector was not even close to being fully threaded into the hub (visually). The electrician, looking to pass the inspection, decided to cut 1/2" of thread off the connector and screw it back into the hub. Now it appeared to be fully threaded, when in fact it was threaded in the same exact amount. The AHJ approved it. He then called to complain to us that the connector or hub was NG. When I told him that the connector was only designed to be used with a locknut and had a straight thread, and that the hub is used secure threaded rigid service entrance conduit to a box or enclosure, he was surprised. He assumed that the hub and the connector had the same thread. He understood that a straight thread and a tapered thread are not really designed to go together.

The UL white book does not prohibit this exact combination, nor does it address field modification of the connector specifically. However, the electrician did misapply the hub application as the literature specified "To secure threaded rigid service entrance conduit to box or enclosure". However, as an engineer, I am not comfortable with his application because I have not evaluated it in a test lab.

It's great that we all live by the letter of the law, but I think sometimes common sense needs to help guide us and our interpretation of the code.

Let me end by saying that I learn a lot from the many great folks in this forum who take the time to educate and discuss issues like these. Thanks!

 

[LJSMITH1]

Check this out from OZ_Gedney regarding chase nipples and rigid conduit couplings.



This can be found on page 4 of this pdf

Now the threads on a chase nipple are no different then the threads on a LFMC or EMT connector.

Considering I have NEVER seen any specific installation directions or labeling on a RMC coupling then using it with connectors is not a violation of 110.3(B)

Great. Then this means O/Z has tested this exact application and verified that it will maintain the integrity of their UL listing. However, if T&B's chase nipple does not have the same specification, then I would counter that it is not the same.

 

[LJSMITH1]

Great. Then this means O/Z has tested this exact application and verified that it will maintain the integrity of their UL listing. However, if T&B's chase nipple does not have the same specification, then I would counter that it is not the same.

Here's T&B's chase nipple specification:
http://www.tnb.com/ps/fulltilt/index.cgi?part=HA210

 

[don_resqcapt19]

Here's T&B's chase nipple specification:
http://www.tnb.com/ps/fulltilt/index.cgi?part=HA210

That spec sheet says for use with rigid or IMC conduit. How do you use it with conduit unless you screw it into a coupling?

 

[iwire]

Great. Then this means O/Z has tested this exact application and verified that it will maintain the integrity of their UL listing.

We have no idea if that is true at all, it could be that they simply know that using a rigid coupling for other purposes then conduit is not prohibited.

After all this you have not shown one reference that this is a violation.

 

[jdsmith]

I am under the impression that in order to have the performance of the product as guaranteed by the UL listing process, it must be used exactly as tested in the UL specification. Any variation from that use, will basically put the fitting in an area of uncertainty because no testing in a controlled environment has been done. Am I misguided?

I agree with you. What we then approach is what we do in the face of an uncertain, untested combination. This becomes a question of individual judgement and must be weighed against the consequences in the event of a connector or raceway failure. The two areas I work in are a refinery and light commercial buldings at my favorite non-profit organization. Obviously I make different cost/performance tradeoffs in the two situations because of differences in risk.

Related issues that come down to judgement:
Steel EMT fittings vs. cast zinc fittings.
Compression EMT fittings vs. setscrew fittings.
Typical zinc locknuts (little ridges that don't cut through paint) vs. zinc locknuts that will cut through paint vs. two styles of steel locknuts vs. malleable locknuts.

 

[iwire]

Lets try this from another direction.

If an NEC inspector feels they must fail an installation they have to cite a code section.

The only possible code section in this case would be 110.3(B)

110.3(B) Installation and Use. Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling.

Now I have never seen any instructions labeled on an RMC coupling, but it certainly is listed.

Now What instruction included in the listing prohibits using the RMC coupling to couple other connectors?

 

[LJSMITH1]

I guess you are right..there are no instructions that I have seen in fitting listings with the exception of cable/conduit diameters. There are no specific instructions on how to use/apply a RMC coupling except on RMC. So I guess the lack of instruction means that its ok to use in a particular application if its not specifically prohibited.

This is really a circular discussion and I will admit I have no code/specific evidence to counter your points.

 

[LJSMITH1]

We have no idea if that is true at all, it could be that they simply know that using a rigid coupling for other purposes then conduit is not prohibited.

After all this you have not shown one reference that this is a violation.

Of course its true, O-Z states it in their sales literature. If they state it, then I would think its been tested for that application. Likewise, T&B's literature only refrences their product to be used with a locknut and does not mention coupling at all. I have provided the link to their catalog page to back up my statement. The violation is obviously not clear...and lack of clarity means its ok, right?

 

[LJSMITH1]

I agree with you. What we then approach is what we do in the face of an uncertain, untested combination. This becomes a question of individual judgement and must be weighed against the consequences in the event of a connector or raceway failure. The two areas I work in are a refinery and light commercial buldings at my favorite non-profit organization. Obviously I make different cost/performance tradeoffs in the two situations because of differences in risk.

Related issues that come down to judgement:
Steel EMT fittings vs. cast zinc fittings.
Compression EMT fittings vs. setscrew fittings.
Typical zinc locknuts (little ridges that don't cut through paint) vs. zinc locknuts that will cut through paint vs. two styles of steel locknuts vs. malleable locknuts.

I am sorry, these are not related issues. You are talking about apples and oranges.

Mixing and matching unlike fittings is VERY different from the issues you listed. All of those issues you stated are handled by the same UL Specification - UL514B. If all of those types of fittings pass UL514B (Zinc, Steel, Compression, SetScrew, etc), then they are ok for all specified applications.

 

[jim dungar]

I guess you are right..there are no instructions that I have seen in fitting listings with the exception of cable/conduit diameters. There are no specific instructions on how to use/apply a RMC coupling except on RMC. So I guess the lack of instruction means that its ok to use in a particular application if its not specifically prohibited.

Honestly, if there are no instructions included how are we to know that something is being done wrong? Can I throw away the locknut that comes with an EMT connector and use one that is a different style or from a different manufacturer; how would I know not to?

 

[LJSMITH1]

Honestly, if there are no instructions included how are we to know that something is being done wrong? Can I throw away the locknut that comes with an EMT connector and use one that is a different style or from a different manufacturer; how would I know not to?

That's a great question, and I wish I had an answer for it. I think many manufacturers have not spent enough time educating the end user - especially with all the new fittings out there. The main reason seems to be that it is 'assumed' that the end user 'knows' how its used and its limitations. The fittings industry is so mature on one hand, yet it has a long way to go on the other.

How do we know a setscrew is tight? UL provides a torque spec. required to meet the minimum pull pounds. However, most electricians I know don't carry a torque screwdriver to tighten fitting setscrews. Its very frustrating, because manufacturers are required to test to a specific number, when we all know that there are weak handed folks and then there are the gorillas... You get screws that are stripped from over-tightening, and then you get complaints about conduit popping out of connectors due to screws not tightened enough.