Strapping Pipe 24" or less

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kjroller

Senior Member
Location
Dawson Mn
Occupation
Master electrician
If I have a nipple that goes in between 2 boxes 24" or less, does it need a strap? Particularly referring to RMC. Also, what code section tells you that please and thanks you.
 
Yes it requires a strap or some other type of support. Look at 344.30(A) there is no exception for when the conduit is less than 3' in length. We did have an exception that lasted only one code cycle (2008) for nipples 18" or less but for some reason the geniuses on that CMP removed it.
 
At least for emt, 36'' unsupported is legal. Mike holt submitted a PI to allow for a 24" unsupported nipple. CMP says a 36" is already allowed.Screenshot_20251218_082106_Instagram.jpg
 
ppsh said:
At least for emt, 36'' unsupported is legal. Mike holt submitted a PI to allow for a 24" unsupported nipple. CMP says a 36" is already allowed.
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Why does that say securing raceway not required within 3' from a coupling? Not sure who wrote that response.
 
infinity said:
Yes it requires a strap or some other type of support. Look at 344.30(A) there is no exception for when the conduit is less than 3' in length. We did have an exception that lasted only one code cycle (2008) for nipples 18" or less but for some reason the geniuses on that CMP removed it.
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I would dispute this. The code doesn't have a definition for secured, however you securely fasten a conduit to a box via a fitting or locknuts. So if you have two boxes within 3 feet of each other, then each box secures the conduit within three feet of a box.
 
It hinges on whether the short length is securely fastened without the additonal strap. The code typically requires fastening within a certain distance of boxes or conduit bodies. The distance depends on the wiring method and so is found in the wiring method article (e.g. 358 for EMT), but is typically 3ft for hard pipe. The code articles for various raceways notably do *not* typically reference straps explicitly, they just say 'securely fastened'.

So here's the thing: if the two boxes are less than 3ft apart, then as long as each connector securely fastens the raceway, each end is securely fastened within 3ft of the other box. 😉

The NEC does not elaborate on 'securely fastened' beyond the dictionary definitions. In my judgment, if I can grab the pipe forcefully and it doesn’t move (typical of a staight piece or nipple), it's securely fastened. If it moves (typical of a pipe with a 90 bend or LB in it), then it it's gonna need additonal strap or two to securely fasten it.
 
jaggedben said:
So here's the thing: if the two boxes are less than 3ft apart, then as long as each connector securely fastens the raceway, each end is securely fastened within 3ft of the other box.
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If the first strap were at 10' from the box then according to your logic the connector is supporting the box within 3'. That's not what the NEC requires.
 
Strathead said:
I would dispute this. The code doesn't have a definition for secured
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'secured' to me depends on context of where the conduit is, that would be hard to pin down in a definition. What can be secured well enough in one area may not be good enough for another.
We had a service call recently where someone evidently locked a very nice bike to a short section of 3/4" EMT.
It was a L between a panel and a bell box no strap and the conduit had a generous offset.
The bike thief probably used the bike as a lever to rip the conduit out.
A 1 hole strap would probably have ripped out anyway.
I guess that area is now a hazardous location subject to physical damage LOL
 
Watch the video.

Mike Holt submitted a PI to allow up to a 24" length of EMT to be supported only by connectors. CMP rejects it, saying 36" is already allowed, referencing 358.30(a)(1).

The 2008 3xx.30(c) rule justification was

"During the 2008 NEC cycle Panel 8 fully
considered the need for adding the section which the submitter proposes to
delete. The Panel determined that the present language was needed to clarify
that short nipples do not require additional support and that this was not
universally understood by AHJ’s, especially in remote & rural areas."


That last sentence tells you that short nipples did not require support prior to the 2008. The section got deleted in 2011, going back to how it was prior to 2008, after a lengthy PI was submitted detailing all of the issues the 2008 change created.


Post in thread 'Nipple support' https://forums.mikeholt.com/threads/nipple-support.145866/post-2284483
 
ppsh said:
That last sentence tells you that short nipples did not require support prior to the 2008. The section got deleted in 2011, going back to how it was prior to 2008, after a lengthy PI was submitted detailing all of the issues the 2008 change created.
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You've got that wrong. The wording was added in the 2008 because it was not permitted to have sections of raceway unsupported. They settled on 18" when certain conditions were met.
 
infinity said:
You've got that wrong. The wording was added in the 2008 because it was not permitted to have sections of raceway unsupported. They settled on 18" when certain conditions were met.
Click to expand...

It is not my interpretation or my opinion. I'm just going of what CMP-8 has stated. I'm not sure of a more direct source.

If CMP-8 states 36" is allowed unsupported under the current 358.30a I'm inclined to believe them.

IAEIs 2011 code change publication even states the same.

Seems it was purposely left vague.

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