6-3 NM Cable in 1-1/4" ENT

[T-Stripes]

Is there a limitation on running 6-3 NM inside a 25'foot run of 1-1/4" ENT (Smurf)? I'm aware of the 1-cable limit of 12-2 (for example) inside conduit over 2 feet in length. Do I need to calculate/de-rate? Usage is a 40A Cooktop (circuit will be 50A as a hedge against a larger need in the future).

 

[Dennis Alwon]

Why are you sleeving it in conduit? Is it indoors or outdoors?

Also Note 9 to Table in Chapter 9

A multiconductor cable, optical fiber cable, or flexible
cord of two or more conductors shall be treated as a
single conductor for calculating percentage conduit or
tubing fill area. For cables that have elliptical cross
sections, the cross-sectional area calculation shall be
based on using the major diameter of the ellipse as a
circle diameter. Assemblies of single insulated conductors
without an overall covering shall not be considered
a cable when determining conduit or tubing fill area.
The conduit or tubing fill for the assemblies shall be
calculated based upon the individual conductors.

 

[T-Stripes]

There is an existing 1-1/4" blue smurf tube integrated into the building construction. It is the only clean access from the garage to the kitchen. Conduit fill won't be an issue with the size of the conduit, but I wondered about any heat limitations, deratings, or any other issue that I am not aware of. I know that conduit fill calcs are all about heat, but I thought there was a rule when there was an overall-jacketed cable run in conduit. It terminates in a low-volt frame but has not been used to run low-volt or anything.

 

[T-Stripes]

Thanks, by the way

 

[don_resqcapt19]

Is there a limitation on running 6-3 NM inside a 25'foot run of 1-1/4" ENT (Smurf)? I'm aware of the 1-cable limit of 12-2 (for example) inside conduit over 2 feet in length. Do I need to calculate/de-rate? Usage is a 40A Cooktop (circuit will be 50A as a hedge against a larger need in the future).

There is no such rule in the NEC...it is totally based on raceway size and area of the conductor, however you have to be careful with Chapter 9, Table 1, Note 9 for flat or elliptical cables as Dennis pointed out in post 2.