# Minimum length of flex?



## qckrun (May 18, 2009)

I was working last week and a very knowledgeable journeyman/foreman that I work with called me out on my length of flex going from my conduit and transisting to a motor. He said that it has to be a minimum of 18" and I asked him where in the code it said that. As any good journeyman would do, he told me to look it up and I did. However in the table for flexible metal conduit, and liquid tight I did not see any minimum length, only minimum and maximum trade sizes. Can someone point me to the right direction, I even looked up in the motor section(which I knew it would not be in) I'm just confused. Maybe one of you can direct me to the correct section.

Thanks


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## user4818 (Jan 15, 2009)

Seeing that you're in California, which does not use the NEC directly and has many local codes, I would imagine you have some state or local rule in play. Hopefully one of the west coast guys will chime in.


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## paul d. (Jul 13, 2008)

some of the job specs i've seen lately say 12" min. paul


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## steelersman (Mar 15, 2009)

I've never heard of a minimum, just a maximum. So there is actually a minimum in some jurisdictions? Like you can't run a 6 inch peice of flex, it has to be at least 18 inches? Weird!!!


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## Speedy Petey (Jan 10, 2007)

paul d. said:


> some of the job specs i've seen lately say 12" min. paul


I have seen and heard quite often where guys will say something is code because it is the way they always did it, or because is always spec'd that way.

Good for you qckrun for questioning this.


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## qckrun (May 18, 2009)

Peter D said:


> Seeing that you're in California, which does not use the NEC directly and has many local codes, I would imagine you have some state or local rule in play. Hopefully one of the west coast guys will chime in.


 Um california does use the NEC directly, but we also have my local codes and specs superciding the NEC. This journeyman was specifically referring to the NEC, which I think he is wrong.

For instance, on the job now, the specs state emt strapping is 30" from box and then every 5'.


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## qckrun (May 18, 2009)

Speedy Petey said:


> I have seen and heard quite often where guys will say something is code because it is the way they always did it, or because is always spec'd that way.
> 
> Good for you qckrun for questioning this.


 The reason I questioned it mainly is because I've done flexing less than 18" and an inspector looked and it specifically and did not say a word actually complemented the work.

I think he might be confused because he was recently in the S.F. area working and they always have local codes in play over the NEC. I'm going to bring the code book tomorrow and have him point it out.


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## paul d. (Jul 13, 2008)

job i'm on now had a 4" rigid stubbed up under a chiller panel. with 4" coupling and flex connector it was only appx. 10" of flex to bottom of panel. engineer did'nt like it , but let it go. and the specs did specify the 12" minimum. rare occurance.


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## rotagilla (Jun 28, 2009)

paul d. said:


> job i'm on now had a 4" rigid stubbed up under a chiller panel. with 4" coupling and flex connector it was only appx. 10" of flex to bottom of panel. engineer did'nt like it , but let it go. and the specs did specify the 12" minimum. rare occurance.


 
Check your spec/contract it maybe there, not a code requirement.
Below is a spec from a job I did last year.
Engineers requirement not code.

3. Flexible Metal Conduit: 
a. Where required, install standard flexible steel metal conduit (not liquid-tight) with internal ground wire, in spaces above ceilings. 
b. Install flexible conduit connection such that vibrations are not transmitted to adjoining conduit or building structure. Maximum length shall be four (4) feet, minimum two (2) feet; minimum size shall be ½-inch. 
c. Communication flexible conduit size in walls shall be minimum 1-inch.
d. Flexible conduit for lay-in fixtures may be 3/8-inch factory whip assemblies (6 feet maximum).


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## drsparky (Nov 13, 2008)

steelersman said:


> I've never heard of a minimum, just a maximum. So there is actually a minimum in some jurisdictions? Like you can't run a 6 inch peice of flex, it has to be at least 18 inches? Weird!!!


California = earthquakes I would guess minimum flex has something to do with that.


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## Bob Badger (Apr 19, 2009)

I have had specs here in MA for FMC and LFMC to be no shorter than 18" and no longer then 36".

The EEs wants what they want.


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## Safety-Guy (Jan 22, 2007)

Check the seismic requirements. I am sure you will find your answer there.


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## Cayers23 (Jan 18, 2021)

rotagilla said:


> Check your spec/contract it maybe there, not a code requirement.
> Below is a spec from a job I did last year.
> Engineers requirement not code.
> 
> ...


That is actually in the 2014 NEC Code Book under section 680.42 liquidthight flexible nonmetallic conduit.


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## CWL (Jul 7, 2020)

Pretty sure the 2014 NEC Code Book wasn't out in 2009 when this post was started.


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## Cayers23 (Jan 18, 2021)

CWL said:


> Pretty sure the 2014 NEC Code Book wasn't out in 2009 when this post was started.


Hahaha, sorry didn't see the date!


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## splatz (May 23, 2015)

Cayers23 said:


> That is actually in the 2014 NEC Code Book under section 680.42 liquidthight flexible nonmetallic conduit.


Is it though?


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## Kevin (Feb 14, 2017)

Cayers23 said:


> That is actually in the 2014 NEC Code Book under section 680.42 liquidthight flexible nonmetallic conduit.


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And as a Canadian, I'd like for you to share what the code book actually says as I am curious but do not have a 2014 NEC book...


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## splatz (May 23, 2015)

> 680.42 Outdoor Installations.
> A spa or hot tub installed outdoors shall comply with the provisions of Parts I and II of this article, except as permitted in 680.42(A) and (B), that would otherwise apply to pools installed outdoors.
> 
> (A) Flexible Connections. Listed packaged spa or hot tub equipment assemblies or self-contained spas or hot tubs utilizing a factory-installed or assembled control panel or panelboard shall be permitted to use flexible connections as covered in 680.42(A)(1) and (A)(2).
> ...


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## Cayers23 (Jan 18, 2021)

Cayers23 said:


> That is actually in the 2014 NEC Code Book under section 680.42 liquidthight flexible nonmetallic conduit.





Kevin_Essiambre said:


> Please see the link below. A profile is required here at Electrician Talk. Please make sure to include occupation and general location.
> 
> 
> 
> ...



Was talking about the comment I actually applied to which was this. See below.

Check your spec/contract it maybe there, not a code requirement.
Below is a spec from a job I did last year.
Engineers requirement not code.

3. Flexible Metal Conduit:
a. Where required, install standard flexible steel metal conduit (not liquid-tight) with internal ground wire, in spaces above ceilings.
b. Install flexible conduit connection such that vibrations are not transmitted to adjoining conduit or building structure. Maximum length shall be four (4) feet, minimum two (2) feet; minimum size shall be ½-inch.
c. Communication flexible conduit size in walls shall be minimum 1-inch.
d. Flexible conduit for lay-in fixtures may be 3/8-inch factory whip assemblies (6 feet maximum).


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## Quickservice (Apr 23, 2020)

qckrun said:


> I was working last week and a very knowledgeable journeyman/foreman that I work with called me out on my length of flex going from my conduit and transisting to a motor. He said that it has to be a minimum of 18" and I asked him where in the code it said that. As any good journeyman would do, he told me to look it up and I did. However in the table for flexible metal conduit, and liquid tight I did not see any minimum length, only minimum and maximum trade sizes. Can someone point me to the right direction, I even looked up in the motor section(which I knew it would not be in) I'm just confused. Maybe one of you can direct me to the correct section.
> 
> Thanks


Your jman is full of beans.


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