Why not use LFNC?

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mikeybmdb32

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My electrical contractor is wanting to install LFNC as opposed to LFMC. The application is per code and specifications, but I've never seen LFNC installed on a job - it's always been LFMC.

Does anyone have an opinion (aside from cost difference) as to why you would want LFMC as opposed to LFNC? Maybe some advantages/disadvantages between the two? Anyone seen long-term issues with LFNC being installed, like maybe it comes apart easily?
 
I have only used LFNC a few times but I think it is a superior product to LFMC, especially in wet locations. It does not take too many years before the metal in the LFMC is rusted away in a wet location, and the non-metallic jacket, at least the part facing the sun, is also gone in about the same time frame when the LFMC is exposed to direct sun light
 
LFNC is cheaper and easier to cut, I would guess that LFMC is somewhat stronger and can in some installations be used without an additional EGC.
 
ptonsparky said:
We use LFNC for most installs. Rarely non metallic fittings.
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Agree regarding the non-metallic fittings. The plastic fittings always struck me as extremely cheap and damage prone. One wonders how they were ever approved. I d like the LFNC though. As others have said, it's easy to cut and work with. I'm not actually sure that LFMC is actually stronger. The jacket is pretty thin, and the metal spiral can unravel. I don't know what the tensile strength of LFNC is, but it seems pretty darn tough.

The necessity of running an EGC is not an issue for me; I'd run an EGC in LFMC as well.



SceneryDriver
 
SceneryDriver said:
Agree regarding the non-metallic fittings. The plastic fittings always struck me as extremely cheap and damage prone. One wonders how they were ever approved. I d like the LFNC though. As others have said, it's easy to cut and work with.
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I do not see any issue with plastic fittings on plastic raceway. If you are securing the raceway as required the fittings should not be under any stress.

Furthermore if you are using plastic raceways and plastic boxes you had better be using plastic fittings to connect them. Grounding isolated metal fittings would be a problem.

I'm not actually sure that LFMC is actually stronger. The jacket is pretty thin, and the metal spiral can unravel. I don't know what the tensile strength of LFNC is, but it seems pretty darn tough.
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I am actually sure it is stronger .... unless it rusts as has been mentioned.
 
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