12/2 UF wire in 1/2" PVC

[Btbamfan4]

View attachment 2553116 View attachment 2553117
I know that's right! Do you know what the other dimensions are on nm?

It has 4 different ones

 

[FionaZuppa]

I'd say that pulling UF in PVC is one of the toughest pulls there are.

In 1/2" PVC too. Will there be any sched 80 in there, yikes.

 

[FionaZuppa]

Why not pull individual wires?

Q - since UF-B is like a formed insulator around the two CCC's & EGC wire, if the EGC wire is bare wire, is it still considered "insulated" EGC ?

 

[Btbamfan4]

Nah, see, all I had was uf on me. I pieced it all together. Literally couplings fittings, pipe, etc. So no wire was damaged. I just wasn't aware that uf needed 3/4. I figured hell you can run 50 amps with #8 thhn in 3/4, so 1/2" should be alright for 12/2. Lol last time I'll "figure" anything

In 1/2" PVC too. Will there be any sched 80 in there, yikes.

 

[winnie]

As noted in post 17 https://forums.mikeholt.com/threads/12-2-uf-wire-in-1-2-pvc.2555307/post-2599671 , if you have a _sleeve_ rather than a _raceway_ you might be kosher.

Loose THHN requires a raceway. But UF is a cable assembly, and could simply be stapled to the joists/studs/etc. In which case the PVC might simply be there for mechanical protection or as a convenient way to support the UF.

You are not permitted to piece together a raceway around loose wires; you have to fit all the bits together and then pull the wires in. But you can assemble a sleeve in whatever fashion makes the most sense mechanically. A raceway needs to be complete from one box to another; but a sleeve can end in free air (possibly with some protection for the exiting cable).

There are probably other requirements that I am forgetting about the differences between the two.

So, do you have a PVC sleeve or a PVC raceway?

-Jon

 

[Btbamfan4]

It would have to since its rated for direct burial

 

[Btbamfan4]

As noted in post 17 https://forums.mikeholt.com/threads/12-2-uf-wire-in-1-2-pvc.2555307/post-2599671 , if you have a _sleeve_ rather than a _raceway_ you might be kosher.

Loose THHN requires a raceway. But UF is a cable assembly, and could simply be stapled to the joists/studs/etc. In which case the PVC might simply be there for mechanical protection or as a convenient way to support the UF.

You are not permitted to piece together a raceway around loose wires; you have to fit all the bits together and then pull the wires in. But you can assemble a sleeve in whatever fashion makes the most sense mechanically. A raceway needs to be complete from one box to another; but a sleeve can end in free air (possibly with some protection for the exiting cable).

There are probably other requirements that I am forgetting about the differences between the two.

So, do you have a PVC sleeve or a PVC raceway?

-Jon

Its piped all the way. TA to TA. FS box to panel. I only had to pipe it, due to the steele structure in the crawlspace. Hence, no where to staple

 

[Btbamfan4]

I'm just going to push it with thhn. Just wasn't aware of uf not being acceptable in 1/2". Kind of a nuisance when they consider the diameter of the sheathing as one conductor. I get pipe fill, but it shouldn't be calculated in for heat measures. At least not when the sheathing is included as a conductor in whole, which produces no heat. Pretty sure its rated at 190°. Theres no way that that wire is getting that hot unless their is a malfunction on the appliance, which the gfi that I installed would trip it before allowing it to draw over 20 amps

 

[FionaZuppa]

As noted in post 17 https://forums.mikeholt.com/threads/12-2-uf-wire-in-1-2-pvc.2555307/post-2599671 , if you have a _sleeve_ rather than a _raceway_ you might be kosher.

-Jon

This is where it's gray for me.
If you "sleeve" it, does that imply "for physical damage protection", or at least subject to applying those words (checks) to the evaluation of the sleeve? If so then it requires sched-80.

Surely not all use of PVC for sleeving is subject to physical damage, but you see what I am driving at.

But, seems the UF will now be a pull for towing a pull string through ??

 

[infinity]

I'm just going to push it with thhn. Just wasn't aware of uf not being acceptable in 1/2". Kind of a nuisance when they consider the diameter of the sheathing as one conductor. I get pipe fill, but it shouldn't be calculated in for heat measures. At least not when the sheathing is included as a conductor in whole, which produces no heat. Pretty sure its rated at 190°. Theres no way that that wire is getting that hot unless their is a malfunction on the appliance, which the gfi that I installed would trip it before allowing it to draw over 20 amps

It has nothing to do with heat that would be derating for more than 3 CCC in the raceway. The fill rule is to ensure that the cable can be pulled in without damage.

 

[Btbamfan4]

It has nothing to do with heat that would be derating for more than 3 CCC in the raceway. The fill rule is to ensure that the cable can be pulled in without damage.

Ground isn't a CCC. I literally pieced every single pipe and fitting together one by one. Nice, neat, and safe. I guess the "removal" of the wire would be the only obstruction which goes against NEC?

 

[Btbamfan4]

It has nothing to do with heat that would be derating for more than 3 CCC in the raceway. The fill rule is to ensure that the cable can be pulled in without damage.

What is the code for pipe fill that insists it's for the damage of installation and not heat? Not doubting you. Just learning

 

[FionaZuppa]

What is the code for pipe fill that insists it's for the damage of installation and not heat? Not doubting you. Just learning

The derating of CCC's accounts for heat, based on a function of fill.
I can argue that NEC kinda wraps physical and heat into the fill rules w/o specifically segregating the two things.

The "in close proximity" statement to the conduit for cooling reasons may be true, but the issues comes from say 3 or 4 wires where 1 or 2 of them are surrounded by the others, making heat movement less able and raising the temp in that local region. So although there "might" be a better heatsink available, the derating math takes into consideration the local heat issue (to some extent).

 

[infinity]

What is the code for pipe fill that insists it's for the damage of installation and not heat? Not doubting you. Just learning

Right here:

300.17 Number and Size of Conductors in Raceway. The number and size of conductors in any raceway shall not be
more than will permit dissipation of the heat and ready installation or withdrawal of the conductors without damage to the
conductors or to their insulation.

As far as derating for more than 3 CCC's in a raceway the NEC doesn't care if it's ½" or 6" conduit, you get no credit for the additional air in a larger raceway.

 

[Btbamfan4]

"Heat and ready" it's for both

 

[Btbamfan4]

Right here:


As far as derating for more than 3 CCC's in a raceway the NEC doesn't care if it's ½" or 6" conduit, you get no credit for the additional air in a larger raceway.

Oh but I see your point. So technically it's not heat even though they say it is? So confusing

 

[LarryFine]

"Heat and ready"

"It's what's for dinner."

 

[ActionDave]

It was all I had on me and I was by myself. I pieced it together in the crawl space and didnt damage the wire. Last time I'll ever do this. I just wanted to make sure I dont have to go back out and repull it in thhn, because I will if I have to

Why are you putting uf inside of conduit if you are in a crawl space?

 

[Btbamfan4]

Why are you putting uf inside of conduit if you are in a crawl space?

Because its underneath a trailer that has a steel bottom. nothing to staple to.

 

[ActionDave]

Because its underneath a trailer that has a steel bottom. nothing to staple to.

Beam clamps and zip ties are your friend next time.