Rough in before Dry in

[don_resqcapt19]

Two better words: heat transfer.

Moving air might remove heat faster than stagnant water.

I don't see any moving air within the NM and the wet paper will increase the heat transfer to the jacket where it is dissipated to the air around the NM jacket.

 

[Dennis Alwon]

Many pickup trucks drive around all day long with nm cable in the back. Do you think they remove it when it rains. LOL

 

[Dennis Alwon]

I am curious why NM paper would not be able to dry out in time. Wouldn't the heat on the conductors dry the paper?

 

[roger]

Many pickup trucks drive around all day long with nm cable in the back. Do you think they remove it when it rains. LOL

My pick up might have boxes of breakers too.

 

[Ohm2]

Sure, but your assumption that dry paper plus air is more thermally conductive than wet paper plus water is unsupported. My guess is it would be the opposite, but without any data, we are just guessing.

Cheers, Wayne

Point: Water has different thermal conductivity compared to air. While water itself can absorb heat, it can also conduct heat away from the conductors less effectively if it displaces air, which is the intended medium for heat dissipation.

 

[wwhitney]

While water itself can absorb heat, it can also conduct heat away from the conductors less effectively if it displaces air, which is the intended medium for heat dissipation.

Intended by whom? Both water and air carry transfer heat via conduction or convection. I bet the water would do a better job at it.

Case in point: it is well known that if you are outdoors hiking and get your clothes wet, most fabrics are going to cease to keep you warm. When wet, they conduct heat away from your body much better than when dry, and you can freeze. [Pretty sure that's not just a surface effect due to the evaporation from the wet clothes, and that if you put a dry waterproof layer on over the wet clothes, the wet clothes would still thermally insulate you worse than dry clothes.]

Cheers, Wayne

 

[Ohm2]

To get back on code as it relates to nm cable: it is not permitted in wet or damp locations. Rather we allow it on our open back truck during rain or we rough it in without a dried-in roof…it doesn’t matter.. code stands

 

[Ohm2]

My pick up might have boxes of breakers too.

Wow

 

[infinity]

To get back on code as it relates to nm cable: it is not permitted in wet or damp locations. Rather we allow it on our open back truck during rain or we rough it in without a dried-in roof…it doesn’t matter.. code stands

Its not permitted to be installed in damp or wet locations but the cable is permitted to be damp or wet during the construction of the building. Those two scenarios are not the same.

 

[jim dungar]

I don't see any moving air within the NM and the wet paper will increase the heat transfer to the jacket where it is dissipated to the air around the NM jacket.

My point was in regard to the issue being heat transfer away from the conductors not heat conductivity of the transfer medium. I don't no what mechanics are really involved in rating NM versus UF conductors.

 

[Ohm2]

Intended by whom? Both water and air carry transfer heat via conduction or convection. I bet the water would do a better job at it.

Case in point: it is well known that if you are outdoors hiking and get your clothes wet, most fabrics are going to cease to keep you warm. When wet, they conduct heat away from your body much better than when dry, and you can freeze. [Pretty sure that's not just a surface effect due to the evaporation from the wet clothes, and that if you put a dry waterproof layer on over the wet clothes, the wet clothes would still thermally insulate you worse than dry clothes.]

Cheers, Wayne

It’s not permitted to be installed in damp or wet locations but the cable is permitted to be damp or wet during the construction of the building. Those two scenarios are not the same.

I can agree!!

 

[Ohm2]

Intended by whom? Both water and air carry transfer heat via conduction or convection. I bet the water would do a better job at it.

Case in point: it is well known that if you are outdoors hiking and get your clothes wet, most fabrics are going to cease to keep you warm. When wet, they conduct heat away from your body much better than when dry, and you can freeze. [Pretty sure that's not just a surface effect due to the evaporation from the wet clothes, and that if you put a dry waterproof layer on over the wet clothes, the wet clothes would still thermally insulate you worse than dry clothes.]

Cheers, Wayne

Hmm strong argument

 

[Hv&Lv]

Without diving too deep into the technicalities of the heat transfer mechanisms that are happening beneath our feet, it is important to note that the presence of air has one of the most negative impacts on the thermal conductivity of a system. Thermal conductivity describes the ability of a materially to effectively transfer heat. If this material is hotter than the surrounding environment and has high thermal conductivity, it will quickly dissipate heat throughout its surroundings.

The presence of air bubbles or pores in the soil will increase its thermal resistivity, in turn decreasing the soil’s thermal conductivity. This increase in resistance experienced by the surrounding environment creates a stronger insulative barrier for the heat that is expelled from the hot electrical wire to pass through. The more air bubbles present in the substrate, the stronger the barrier and the quicker the cables will overheat.

A quick fix to this disastrous problem is increasing the water content of the soil which results in an increase in thermal conductivity. Water naturally has a higher thermal conductivity than air, so replacing air bubbles with water molecules is seen as a convenient solution to dissipate more heat from an underground cable. In many regions, this is easier said than done. Depending on the type of soil (in which there are a seemingly endless number of categories), water infiltration can have little to no effect on the overall thermal conductivity of the soil.

The Effects of Soil Thermal Conductivity on Energy Transfer

Exploring the underground Cable Systems and the effects of the thermal conductivity of soil on energy transfer.

thermtest.com

 

[kwired]

I think the bigger issue than whether Romex can get mist on it is, if you’re roughing in before dry-in, there’s a bunch of other issues:

-Are HVAC and plumbing done as well? Because we generally come after those guys.

-Siding nails and nails used for sheathing and shear walls are usually a lot longer than a drywall screw for 1/2” rock. Chances of (many) nails penetrating your wiring goes way up.

-Chances of having something damaged when major framing is still going on, goes up.

-There is probably a ton of blocking that still need to be installed, and the possibility of your wiring being in the way of at least some of it is close to 100%.

Just a couple things to keep in mind.

none of which are the inspector's problems, this is between the EC and those other trades.

 

[kwired]

Or some scumbag coming in and cutting out all of the copper.

That can happen even after it is "dried in"

 

[kwired]

I've seen NM cable run in raceways outdoors that had been there for 20 years without an issue. The thought that some rain or water hitting the cable during construction is going to permanently damage it seems far fetched to me.

Even underground where water will accumulate and stay in said raceway

 

[Birken Vogt]

I've seen NM cable stapled to a board fence in direct sunlight between a woodshed and chicken house for decades with the outer jacket pretty much dust, and people climbing over said fence, and Zinsco breaker protecting, continue to hold up and carry electricity just fine.

 

[Little Bill]

I will fess up and say I have a run of NM in conduit for a shed that I put in years ago before I knew NM wasn't allowed in conduit outdoors. I haven't pulled it out to look at it, but I've had zero problems with it. It is GFCI protected.

 

[retirede]

My dad’s old house originally had 4 individual conductors ran overhead 30’ to a detached garage. L, N, and 2 switch legs. Somebody replaced them with 2, 12-2 NM cables, using the bare copper as the messenger. It was still intact and working fine when he died. Don’t know how many decades it was like that.

 

[Knightryder12]

As Rob mentions in post #15, on large projects you can not risk falling behind especially if there are $1,000 or more per day Liquidated Damages. You start as soon as you can. We would mobilize and start installing early in the project as did most other subs.

As a former field electrician and project foreman, other than the site people, we were usually the first ones in and the last to leave.