RMC threaded coupling U.L. listing

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Smart $

Esteemed Member
Location
Ohio
Debatable: Code vs. Listing (design, instructions).

It's been practiced by many without consequence, and will continue to be practiced by many. However, there are AHJ's and others that say a LFMC connector is designed for raceway termination at/through an enclosure KO and not for theading into an RMC coupling.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
Debatable: Code vs. Listing (design, instructions).

It's been practiced by many without consequence, and will continue to be practiced by many. However, there are AHJ's and others that say a LFMC connector is designed for raceway termination at/through an enclosure KO and not for theading into an RMC coupling.

How would that be different than using an EMT connector threaded into an RMC conduit body?
 

iwire

Moderator
Staff member
Location
Massachusetts
Debatable: Code vs. Listing (design, instructions).

It's been practiced by many without consequence, and will continue to be practiced by many. However, there are AHJ's and others that say a LFMC connector is designed for raceway termination at/through an enclosure KO and not for theading into an RMC coupling.



I agree with Smart even though I have done it and will do it again.
 

fmtjfw

Senior Member
2013 UL White Book CONDUIT FITTINGS (DWTT) listing

2013 UL White Book CONDUIT FITTINGS (DWTT) listing

Debatable: Code vs. Listing (design, instructions).

It's been practiced by many without consequence, and will continue to be practiced by many. However, there are AHJ's and others that say a LFMC connector is designed for raceway termination at/through an enclosure KO and not for theading into an RMC coupling.

This category covers metallic and nonmetallic conduit fittings, such as connectors, couplings, conduit bodies, short-radius conduit bodies, expansion fittings, locknuts and sealing (liquid-tight) locknuts for use in the assembly of nonmetallic and metallic wiring systems. Also covered are fittings used to provide a transition between metallic and nonmetallic wiring systems. All fittings are intended to be installed in accordance with ANSI/NFPA 70, ??National Electrical Code?? (NEC), and are intended for installation and use in accordance with the following information and the limitations specified in the appropriate conduit or tubing category.

Some of these fittings are also suitable for use in certain hazardous (classified) locations where unclassified locations fittings are permitted in Articles 501, 502, 503, 505 and 506 of the NEC.

This category also includes metal bushings for use in conduit and insulating bushings for use on conduit inside boxes, gutters, etc.

The individual certifications for each connector used with non-metallic-sheathed cable may have details about the size and number of the nonmetallic-sheathed cable it will secure.

All male threaded fittings and nipples have only been investigated for use with locknuts.

Fittings with internal female threads (e.g., hubs, conduit bodies, couplings) have only been investigated for use with threaded rigid conduit.


....

The male threads on fittings are not tapered threads.

Nipples may or may not be tapered threads.

The female threads and designed to work (only?) with tapered threads.

Throw the implications of DWTT in the middle of an IAEI meeting and you will be entertained with a minimum ? hour cat fight. (I know, I've done it.) The UL rep will respond with the DWTT verbiage and then sit back.
 

texie

Senior Member
Location
Fort Collins, Colorado
Occupation
Electrician, Contractor, Inspector
How would that be different than using an EMT connector threaded into an RMC conduit body?

Not compliant either. EMT fittings are covered under FKAV and are only investigated for use with lock nuts. Same as KDER and DWTT for other related products. I know, this is just crazy. Any time I mention this to our UL rep I get the standard answer of "these were not investigated for this use". Well gee, wouldn't you think that after 50 or so years of folks using these products this way that somebody would say "lets investigate and get 'em listed" for this use?
 

xformer

Senior Member
Location
Dallas, Tx
Occupation
Master Electrician
Debatable: Code vs. Listing (design, instructions).

It's been practiced by many without consequence, and will continue to be practiced by many. However, there are AHJ's and others that say a LFMC connector is designed for raceway termination at/through an enclosure KO and not for theading into an RMC coupling.

I agree with this..
 

fmtjfw

Senior Member
Not compliant either. EMT fittings are covered under FKAV and are only investigated for use with lock nuts. Same as KDER and DWTT for other related products. I know, this is just crazy. Any time I mention this to our UL rep I get the standard answer of "these were not investigated for this use". Well gee, wouldn't you think that after 50 or so years of folks using these products this way that somebody would say "lets investigate and get 'em listed" for this use?

Then they would have to rewrite the standard, and possibly delist a whole bunch of stuff that does not meet the new standard.

As a practical matter nothing will change until and unless inspectors start failing installations that violate the listings.
 
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fmtjfw

Senior Member

Do you want UL to come up with parallel standards for all the current fittings listings with the added requirement that they work properly with tapered threads for the males and untapered threads for the females?

Or do you think that all the current fittings can work unaltered?

Last time I started the cat fight, a manufacturer came up to me and said, "we'll get our fittings listed for both." I doubt it since I don't know such a fitting standard exists.

I'll see if they are at the Western Section IAEI meeting this Sep. and ask what progress they have made.

I'm not against it at all, but without inspector pressure there is a small to none market.
 

Smart $

Esteemed Member
Location
Ohio
Then they would have to rewrite the standard, and possibly delist a whole bunch of stuff that does not meet the new standard.

As a practical matter nothing will change until and unless inspectors start failing installations that violate the listings.
Exactly. There's basically only two issues in play: 1) retention, and 2) grounding capabilities. Where connectors are made up wrench tight in threaded couplings, bosses or hubs, I believe the connection will prove to be superior.
 

OTT2

Senior Member
Location
Orygun
Then they would have to rewrite the standard, and possibly delist a whole bunch of stuff that does not meet the new standard.

As a practical matter nothing will change until and unless inspectors start failing installations that violate the listings.

This has been discussed in IAEI meetings before.

You guys go first and we'll see how that works for you. :huh:
 

jusme123

Senior Member
Location
NY
Occupation
JW
...the manufactures don't want it changed , it would result in them not being able to sell the overpriced "fromto's":rant:
 
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