Burying Liquid tight flexible metallic conduit

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mooreaaryan

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Bakersfield CA
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Can I bury Ltfmc? Do I need special fittings to use it under ground. Any words of advice and cautions that I need to take. The only reason I ask is because we have piping underground and can not get around them with pvc or rigid but the flew does fit
 
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mooreaaryan

Member
Location
Bakersfield CA
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Electrician
don_resqcapt19 said:
See 350.10(3), however I am not sure that the connectors are suitable for underground use. Also remember that the degrees of bend in the LFMC count towards the maximum of 360° between pull points.
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We are looking at about 270degree max I’ve reached out to T&B for cut sheet and spec hopefully that will clarify. Others have said they’ve done it with no known issues. I’ve have never tried
 
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curt swartz

Electrical Contractor - San Jose, CA
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San Jose, CA
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Electrical Contractor
I know I have used NM that is listed for DB but don't remember seeing the DB listing on any of the Metallic I have installed. I have never seen a metal connector listed for DB.

I personally would never bury either. I have use short runs of NM in curved concrete walls to connect lighting boxes.

What size raceway are you installing? Unless it is very large I could bend PVC to fit.
 
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ramsy

Roger Ruhle dba NoFixNoPay
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LA basin, CA
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Service Electrician 2020 NEC
Fred B

Fred B

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Upstate, NY
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ramsy said:
Complies with UL standards 360, File Number E34028

On-line retailer using UL file number without showing manufacturer, or UL stamp anywhere on any packaging, or product.
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Have you bought from them? The web page states it is UL Listed and CSA Certified when clicking on "More Information". I can't speak to accuracy so if you have knowledge of this or other product from them that would indicate this is not accurate, please let us know.
 
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jap

Senior Member
Occupation
Electrician
I can honestly say I've never buried a piece of LTFMC or LFNC in my career.

JAP>
 
don_resqcapt19

don_resqcapt19

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Illinois
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retired electrician
ramsy said:
Complies with UL standards 360, File Number E34028

On-line retailer using UL file number without showing manufacturer, or UL stamp anywhere on any packaging, or product.
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Most of the time when a manufacturer says "complies with xxxx", it means they have self evaluated the product to the standards and have not had it tested to the standards by a listing agency.

The file number belongs to INTERNATIONAL METAL HOSE CO, but cannot tell from the site if that is the actual product.

Am always very suspicious of any product where they have used the "complied with" language in relation to a listing.
 
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mooreaaryan

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Bakersfield CA
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Electrician
Fred B said:
Here is one source for DB rated flex there were others.

www.wireandcableyourway.com

3 in. Liquid-Tight Flexible Metallic Conduit, Type UA, 25ft Coil

3" (LFMC) Liquid-Tight Flexible Metal Conduit, Type UA, 25ft Coil
www.wireandcableyourway.com www.wireandcableyourway.com

My question is how are you bonding that section of flex to the EGC? [2017 NEC 250.4(A)(2),(3)]

LFNC non-metallic only found sizes up to 2 inches, so that probably won't help.
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I don’t think it’s likely to become energized… but honestly didn’t consider it….I’ll have to dig around and find someway that the ahj will approve
 
don_resqcapt19

don_resqcapt19

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wwhitney said:
(2017) 250.86 Exception 3(1) would permit the short section of LFMC to be unbonded if it has at least 18" of soil cover?

Cheers, Wayne
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yes, if the raceway is non-metallic, but that has nothing to do with my comment. The "likely to be energized" does not play any part in the code requirements for a metallic raceway to be connected to an EGC.
 
R

ramsy

Roger Ruhle dba NoFixNoPay
Location
LA basin, CA
Occupation
Service Electrician 2020 NEC
Fred B said:
Have you bought from them? The web page states it is UL Listed and CSA Certified when clicking on "More Information". I can't speak to accuracy so if you have knowledge of this or other product from them that would indicate this is not accurate, please let us know.
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No, just expecting everything sold exclusively on-line to be counterfeit, or poision until proven otherwise.

The lack of packaging, cut sheet, or listing is how phony knock offs are sold.
 
don_resqcapt19

don_resqcapt19

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Location
Illinois
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retired electrician
petersonra said:
There used to be a lot of unlisted liquid tight that was sold. It was half the price of the listed stuff.
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Yes, at some of the supply houses around here, that is still what you get, unless you specify you want the listed version, even though the code has required the listed version since the 1996 edition.
 
qcroanoke

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
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Sorta retired........
petersonra said:
There used to be a lot of unlisted liquid tight that was sold. It was half the price of the listed stuff.
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I sent back more than one roll because it wasn't listed. Purchasing just sees the price and can't understand why we can't use it even though it's not listed.....
 
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mooreaaryan

Member
Location
Bakersfield CA
Occupation
Electrician
Well everyone. We ended up rerouting customers pipe. Nobody was 100% comfortable bring LTFMC underground had schedule 40 pvc heated up and very meticulously bent it into place Fun fun fun
 
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