L.B.'s and LFMC fittings

[qcroanoke]

is it code compliant to use a LFMC fitting (or any other type fitting) in a threaded L.B. or is it only legal to thread rigid into them?
Compliant, not an industry wide accepted practice.

 

[Buck Parrish]

IMO metal to metal would be fine.

 

[dkidd]

See post #2

Using Rigid coupling for transitioning

Saw article in ( IAEI ) about using rigid couplings for transitioning from say emt to liquid tight conduit . ( Transitioning Between Raceway's ) Have always seen it done this way emt connector to rigid coupling to liquid tight conduit . Is this now considered wrong and are inspectors now...

forums.mikeholt.com

 

[dkidd]

 

[infinity]

The technical answer is RMC or IMC only due to the listing limitations. The practical answer is that it's done everyday without issue. IMO if the just required an EGC when using other than RMC or IMC the problem is solved.

 

[wwhitney]

There are also combination LBs that have both threads and set screws, marketed for both rigid and EMT. Seems like using a threaded fitting in those along with the set screw would be fine on all technical fronts, although likely not a tested combination.

Cheers, Wayne

 

[infinity]

We've been discussing this for over a decade. You would think by now those guys over at UL who are all asleep at the wheel would have addressed this by now.

 

[don_resqcapt19]

We've been discussing this for over a decade. You would think by now those guys over at UL who are all asleep at the wheel would have addressed this by now.

Not really UL....manufacturers don't want to pay the extra costs to get their connectors evaluated for use with fittings having female threads.

 

[infinity]

Not really UL....manufacturers don't want to pay the extra costs to get their connectors evaluated for use with fittings having female threads.

Doesn't UL typically write the standard? There is no reason why the standard cannot reflect the real life everyday use.

 

[don_resqcapt19]

Doesn't UL typically write the standard? There is no reason why the standard cannot reflect the real life everyday use.

UL Standards are written pretty much like the code is....based on submitted proposed changes.

 

[synchro]

is it code compliant to use a LFMC fitting (or any other type fitting) in a threaded L.B. or is it only legal to thread rigid into them?
Compliant, not an industry wide accepted practice.

I believe typical fittings for LFMC have NPT tapered threads like RMC and IMC. But fittings for connecting EMT to boxes or enclosures are NPSM straight threads.

 

[don_resqcapt19]

I believe typical fittings for LFMC have NPT tapered threads like RMC and IMC. But fittings for connecting EMT to boxes or enclosures are NPSM straight threads.

The issue is that they are not marked as required in the UL Guide Information for "Conduit Fittings (DWTT)". It is my understanding that they are not so marked because the manufacturers have not had their fittings evaluated for that use.

Male fittings not provided with a locknut, intended for securement to a threaded hub, are marked on the smallest unit shipping carton, "For securement to a threaded hub only," or the equivalent.

Male fittings provided with a locknut, also intended for securement to boxes with threaded entries, hubs or fittings with internal female threads (e.g., conduit bodies, couplings), are marked on the smallest unit shipping carton, "For securement to a threaded hub," or the equivalent.