Liquid tight NON metal Flex VS Liquid tight flex metal conduit

[brother]

why is Liquit tight Flex NON metal, can be installed in lengths longer than 6ft where the 'length is approved as ESSENTIAL for a degree of flexibility, 356.12 (no straps required) and Liquid tight flex metal conduit is not, other than the fished etc.. 350.30(A)
NEC 2008??? it appears to me it should be same.

Its a technicality but Ive run into a situation where the ltfmc had to be run longer 6ft (about 7ft 5) and they are secured within 12 in of a box, the other end comes off the end of conduit. Just found it odd the code would allow for it to be ok for ltfnm and not lifmc.

 

[infinity]

Not sure I understand the question. Are you saying that LFMC cannot be run more than 6'?

 

[walkerj]

LTFMC cannot be used as an EGC for more than 6'.
You can run it as far as you want if it has a ground wire and is secured properly

 

[don_resqcapt19]

LTFMC cannot be used as an EGC for more than 6'.
You can run it as far as you want if it has a ground wire and is secured properly

...and you have less than 360 degrees of bend...every little sag counts:grin:

 

[brother]

Not sure I understand the question. Are you saying that LFMC cannot be run more than 6'?

Read the articles carefully, and no im not talking about grounding issues. Yes you can run ltfnc more the 6ft WITHOUT SUPPORT IF'length is approved as ESSENTIAL for a degree of flexibility, 356.12 (no straps required) but ltfmc does NOT have that exception for it, it only allows it if it is FISHED. You MUST support ltfmc, unlike ltfnc.

 

[M. D.]

...and you have less than 360 degrees of bend...every little sag counts:grin:

Tell me about it:roll: I sag in places I never imagined could sag:grin:

 

[infinity]

Read the articles carefully, and no im not talking about grounding issues. Yes you can run ltfnc more the 6ft WITHOUT SUPPORT IF'length is approved as ESSENTIAL for a degree of flexibility, 356.12 (no straps required) but ltfmc does NOT have that exception for it, it only allows it if it is FISHED. You MUST support ltfmc, unlike ltfnc.

OK let's start by making this easier to follow along. Liquidtight Flexible Metallic Conduit is know in the NEC as LFMC. Liquidtight Flexible Non-Metallic Conduit is LFNC.

So the real question is what does this mean:

356.12 Uses Not Permitted

LFNC shall not be used as follows:

(3)In lengths longer than 1.8 m (6 ft), except as permitted by 356.10(5) or where a longer length is approved as essential for a required degree of flexibility.

My guess is that if a situation arose when more then 6' were required for flexibility then it's usage would have to be approved by someone, probably the AHJ. I honestly don't know why this is allowed for LFNC and not LFMC.

Good question. :wink:

 

[brother]

OK let's start by making this easier to follow along. Liquidtight Flexible Metallic Conduit is know in the NEC as LFMC. Liquidtight Flexible Non-Metallic Conduit is LFNC.

So the real question is what does this mean:




My guess is that if a situation arose when more then 6' were required for flexibility then it's usage would have to be approved by someone, probably the AHJ. I honestly don't know why this is allowed for LFNC and not LFMC.

Good question. :wink:

Good, Im glad you got the 'jist' of my question, in my opinion, it should be MORE approved for LFMC than LFNC. Maybe its time for a code proposal/change.