3" Nipple Strapping

Status
Not open for further replies.
T

Tpiekarczyk

New User
Location
San Dieog, CA
Had a discussion with another electrician and he said this is code compliant. I don't believe it is because of 314.23 (E) What is your interpretation? This is a SPS (secure power supply) switched receptacle mounted to an inverter in a residential application.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
IMO, 344.30(C) would allow the nipple to be unsupported but 314.23 would require the box to be supported by a means other than the nipple.
 
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Until such time as the NEC has a rule that says the conduit termination is permitted to serve as a conduit support, it is my opinion that all conduits and nipples, no matter how short, require a support.
 
G

GoldDigger

Moderator
Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
don_resqcapt19 said:
Until such time as the NEC has a rule that says the conduit termination is permitted to serve as a conduit support, it is my opinion that all conduits and nipples, no matter how short, require a support.
Click to expand...
I would love to see an inspector insisting on support for a close nipple joining two adjacent boxes. :)
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
For a code cycle you were allowed to have up to 18" nipples without support. Why they went back to the original rule that requires a support even for the nipple installation shown in the photo is beyond me. :slaphead:
 
resistance

resistance

Senior Member
Location
WA
infinity said:
For a code cycle you were allowed to have up to 18" nipples without support. Why they went back to the original rule that requires a support even for the nipple installation shown in the photo is beyond me. :slaphead:
Click to expand...
So they can add it again in the next code cycle. Heck, they are running out of ideas. :lol:
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
infinity said:
For a code cycle you were allowed to have up to 18" nipples without support. Why they went back to the original rule that requires a support even for the nipple installation shown in the photo is beyond me. :slaphead:
Click to expand...

With realization that the IAEI "NEC 11 Analysis of Changes" is an opinion, it appears to me (another opinion) that they are saying the change from '08 to '11 where ***(C) was omitted, allows 3 ft of unsupported conduit between terminations.
 
C

Carultch

Senior Member
Location
Massachusetts
augie47 said:
With realization that the IAEI "NEC 11 Analysis of Changes" is an opinion, it appears to me (another opinion) that they are saying the change from '08 to '11 where ***(C) was omitted, allows 3 ft of unsupported conduit between terminations.
Click to expand...


I think that was the intent of the proposal and change from '08 to '11, but that still did not make the actual text. There is nothing in the NEC that qualifies a termination as a support.

According to any NEC text other than that in 2008, you would still need a strap on a close nipple (which is not only ridiculous to require, but also impossible). In my opinion, I agree with the 18" rule for just about any non-flexible conduit type, and I'd agree with a distance up to 1 ft with most flexible types, where 12" is the distance required to the first support.

In the case of the OP's photo, even if we'd conclude that no support is necessary for the conduit, I'm sure we all can agree that the box itself needs to be supported by another means, than just the conduit.
 
Last edited:
don_resqcapt19

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
augie47 said:
With realization that the IAEI "NEC 11 Analysis of Changes" is an opinion, it appears to me (another opinion) that they are saying the change from '08 to '11 where ***(C) was omitted, allows 3 ft of unsupported conduit between terminations.
Click to expand...
I don't see how the code wording that says a conduit must be supported with 3' of a box, can be read as saying unsupported conduits up to 3' are permitted.
The issue is that the conduit must have a support and there in nothing in the conduit articles to say that the conduit termination is also a support. We have a couple of cases in the flexible conduit and cable rules where the code says that the termination is the support. We do not have such a code rule for the rigid conduits.

It remains my opinion that any nipple, no matter how short, is required by the code rules to be secured and supported.
 
infinity

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
The 2008 had this as a code change:

344.30(C) Unsupported Raceways. Where oversized, concentric
or eccentric knockouts are not encountered, Type RMC
shall be permitted to be unsupported where the raceway is
not more than 450 mm (18 in.) and remains in unbroken
lengths (without coupling). Such raceways shall terminate
in an outlet box, junction box, device box, cabinet, or other
termination at each end of the raceway.
Click to expand...

The 2011 deleted 344.30(C).
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Don, Rob: I follow what you are saying and don't disagree with you on the wording.
As stated, it does appear, to me, that the Analysis interprets it differently but that is, of course, an opinion.
I doubt any of the local inspectors would reject the OPs install on "conduit support", but many might on "box support"
 
kwired

kwired

Electron manager
Location
NE Nebraska
And back when they had that 18" rule I remember having discussion at a CEU class, an inspector was the instructor, and he even mentioned an example of a piece of 3" RMC 24" long between two cabinets and the fact that if one were to put a strap on that raceway that the raceway likely supports the strap more so then the strap supports the raceway - and I totally agree with that, same concept applies to the nipple in the OP.
 
kwired

kwired

Electron manager
Location
NE Nebraska
tom baker said:
The intent of Ryans proposal was to get the interpretation of the rule. Strapping a 1/2" 12" long makes sense, what about a 3" dia x 12" long?
Click to expand...

Sorry but 1/2 x 12 doesn't make much sense to me. Where is it going to go? And if it is going to go a measly 1 hole strap isn't going to change anything in most instances.

1/2 x 36 is usually well enough supported IMO. As has already been mentioned NEC needs to clarify whether the termination is sufficient for support.
 
Status
Not open for further replies.
Top