Elec83
Member
- Location
- Wheat ridge, Colorado, USA
I just need to know if I am allowed to install 2 14-2 romex cables in 1/2” EMT as long as it is inside?
The fill limits for raceways are for protection of the conductors or cables from damage when they're installed.Ohhhhhhh, but you can have wire completely surrounded by insulation. Where’s the fill calculation for that?
It’s just a chase.
And that’s why nm-b uses 60* column for ampacity, cause it is often encapsulated with no free air space.
Easy, just want to ruffle feathers.
If it is used as a sleeve for protection, not a raceway, then I think the fill tables would not apply. If used as a raceway, then I think a inspector could kick it for the wire in the cable not being labeled with temp rating and such because the sheath should be removed past the transition fitting. I know of inspectors that kick mc cable for the same reason.
I worked with one electrician years ago, when you would ask how many 3/0 would fit in a 2” conduit, he would say “How many do you need!” LOL!(2 ) 14/2-g nm-b wires will fit in 1/2” EMT no problem, (2) 12/2-g nm-b wires still no problem. Get to 3 you might need a shoe horn and lube.
It depends on the length of the sleeve. Look at note 2 in chapter 9 & 4OK, if they fit OK you woud still have to de-rate? More than 3 conductors. Unless it was not a raceway but a short protective sleeve?
Notes to Tables
(1) See Informative Annex C for the maximum number of
conductors and fixture wires, all of the same size (total
cross-sectional area including insulation) permitted in
trade sizes of the applicable conduit or tubing.
(2) Table 1 applies only to complete conduit or tubing
systems and is not intended to apply to sections of
conduit or tubing used to protect exposed wiring from
physical damage.
(3) Equipment grounding or bonding conductors, where
installed, shall be included when calculating conduit or
tubing fill. The actual dimensions of the equipment
grounding or bonding conductor (insulated or bare)
shall be used in the calculation.
(4) Where conduit or tubing nipples having a maximum
length not to exceed 600 mm (24 in.) are installed
between boxes, cabinets, and similar enclosures, the
nipples shall be permitted to be filled to 60 percent of
their total cross-sectional area, and 310.15(B)(3)(a)
adjustment factors need not apply to this condition.
So what would apply to a sleeve that is not a complete conduit system as mentioned in note #2?It depends on the length of the sleeve. Look at note 2 in chapter 9 & 4
I would cut the sheathing off and then run it into the EMT, NM does not pull well around 90s or offsets. Easiest thing to do is get some THHN off your truck and run it
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So what would apply to a sleeve that is not a complete conduit system as mentioned in note #2?
This is the part that is unclear to me when it comes to sleeves over 24". 310.15(B)(3) is for cable bundling when not in a raceway. Doesn't make any sense to me.In terms of bundling then you are stuck with anything over 2' but for fill it is not clear and apparently any length could be used without fill being of concern, IMO.... Obviously I don't think that is the intent. One could argue that if the sleeve is not being used as protection at a certain spot of the run. But as I see it, a 10' stick of pvc stubbed up the wall in a basement from a receptacle has no fill requirements.
310.15(B)(3) Adjustment Factors.
(a) More than Three Current-Carrying Conductors. Where the number of current-carrying conductors in a raceway or cable
exceeds three, or where single conductors or multiconductor cables are installed without maintaining spacing for a continuous length longer than 600 mm (24 in.) and are not installed in raceways, the allowable ampacity of each conductor shall be reduced as shown in Table 310.15(B)(3)(a). Each current-carrying conductor of a paralleled set of conductors shall be counted as a current-carrying conductor.