Is there a maximum length for a conduit sleeve? I am trying to figure out if what I need to install is considered a sleeve or a conduit run for telecommunication cables. I have a distance of 25' that I need to get across that has a hard ceiling. I could not find anything in the 2014 NEC book.
Conduit Sleeve Lengths
- Thread starter superki
- Start date
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fmtjfw
Senior Member
- Location
- Fairmont, WV, USA
There is no NEC limit on the length of conduit used as sleeves.
Actually there is no limit on the length of conduit used as "conduit" either.
Actually there is no limit on the length of conduit used as "conduit" either.
- Location
- Illinois
- Occupation
- retired electrician
If the raceway terminates in an enclosure at each end, then it is a conduit.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
is that in the code somewhere?
how about a piece of emt used to route conductors out of a cable tray? is that conduit? is it a sleeve? a raceway?
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
Or a very small enclosed cable tray? :lol:
- Location
- Illinois
- Occupation
- retired electrician
In my opinion, that is a conduit system and not a sleeve.
This is not really in the code as far as I know.
kwired
Electron manager
- Location
- NE Nebraska
[h=2]300.12Mechanical Continuity ? Raceways and Cables.[/h]Metal or nonmetallic raceways, cable armors, and cable sheaths shall be continuous between cabinets, boxes, fittings, or other enclosures or outlets.
If it is not continuous between cabinets, boxes, fittings, etc it is a sleeve and not a raceway.
If it is not continuous between cabinets, boxes, fittings, etc it is a sleeve and not a raceway.
IMO 300.12 does not distinguish between raceway or sleeve, it just requires the raceways to be mechanically continuous. If it is not mechanically continuous then it is an installation violation. Not necessarily a raceway or sleeve issue.
kwired
Electron manager
- Location
- NE Nebraska
You are correct, but if it is not mechanically continuous it is one step in the wrong direction for raceway usage. A raceway "system" must be complete. A sleeve is for physical protection only and the wiring method being protected needs to be one that is a "stand alone" wiring method. You can "sleeve" a piece of NM cable with a material that is listed for use as a raceway to provide additional physical protection where necessary. You however can not "sleeve" a group of THHN/THWN conductors in a similar manner - those must be installed in approved raceways or wireways, and they must be complete between enclosures - with limited exceptions.
- Location
- Massachusetts
Where are you finding the definition raceway system?
If I instill a few lengths of conduit from a cable tray with a bushing at each end that is a complete system is it not?
kwired
Electron manager
- Location
- NE Nebraska
That is one of the limited exceptions.
- Location
- Massachusetts
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I don't believe a cable tray is considered a raceway
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Not sure what the op is trying to accomplish. Are you concerned that a long sleeve is not allowed? or are you thinking fill capacity? etc
- Location
- Illinois
- Occupation
- retired electrician
My opinion of a complete raceway is one that is terminated at an enclosure at each end. If it is connected to the cable tray and connected to an enclosure at the other end, I would see it as a complete system. If it is connected at the tray, but not to an enclosure at the other end, I would see it as a sleeve.
Just my opinion and no code other than 300.12 to back up my opinion.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
What about parallel service conductors that enter an MCC with no bottom? Just messing with you
kwired
Electron manager
- Location
- NE Nebraska
Sorry Bob, I don't know a lot about cable trays. Assuming what was proposed is allowed - it has to be permitted someplace else (ike in art 392 somewhere) instead of being an exception to the general rule. I kind of looked a little through 392 but did not find what I was looking for, but maybe it is there and I am not quite understanding it as well since I am not so familiar with cable trays. Maybe calling it an exception was the wrong thing to do, even though it essentially is an exception to the general rule.
sgtsparky
Member
- Location
- Dexter, Oregon, USA
I was also looking for sleeve length but could not find it,
in my state NMB is allowed to be sleeved or in nipples in vertical runs outside (yes I know this is a wet location) but i haven't found the maximum length my location Oregon, my reference: statewide alternate method 08-03.
in my state NMB is allowed to be sleeved or in nipples in vertical runs outside (yes I know this is a wet location) but i haven't found the maximum length my location Oregon, my reference: statewide alternate method 08-03.
sgtsparky
Member
- Location
- Dexter, Oregon, USA
i did have a note in my code book that a sleeve was limited to 10' but can not find where I got that from.
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